GB2474936A

GB2474936A - A panel for lining railway arches

Info

Publication number: GB2474936A
Application number: GB1017665A
Authority: GB
Inventors: Steven Caffall Finch
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-10-03
Filing date: 2008-10-03
Publication date: 2011-05-04
Anticipated expiration: 2028-10-03
Also published as: GB201017665D0; AU2008306580B2; GB2475137B; GB201017667D0; EP2231940A2; WO2009044277A2; GB2475138A; GB2475137A; GB2453840B; GB2453840A; JP2011516754A; AU2008306580A1; GB2475138B; GB201017666D0; EP2231940B1; WO2009044277A3; JP5630764B2; GB2474936B; GB201017669D0; GB0818127D0

Abstract

A panel 200 comprising a front surface 204, an opposing rear surface 212 and at least one attachment portion (206, fig 35c); the panel further comprising an upper wall (225, fig 36b) and a lower wall 215 wherein the upper wall extends from the rear surface proximate the upper edge of the panel and the lower wall extends from the rear surface proximate the lower edge of the panel. The panel may include a body portion 201 which may be rigid foamed plastics material. The body portion may include a plurality of channels (213, fig 35a) and the channels may increase in depth towards the lower edge of the panel. In use, water-shedding structures on lateral portions of the shield overlap the panels to provide a waterproof lining without seals.

Description

Panels and shields for lining railway arches This invention relates to systems, methods and apparatus for lining arched structures and for installing mezzanine floors, particularly in railway arches.

Railway arches are the spaces defined between the adjacent piers of an arched viaduct supporting a railway line, and are commonly adapted to accommodate light industrial, storage, retail, office and other commercial activities. Other arched structures include tunnels, vaults and the like.

A viaduct comprises a plurality of spaced-apart, usually parallel piers, each being a masonry structure extending transversely across the width of the viaduct and upwardly from a foundation, with an arched masonry structure known as a barrel supported between each adjacent pair of piers so that its soffit or intrados (the downwardly facing, curved surface) meets each pier along a usually horizontal line, not always visually discernible, known as the spring.

The width of the arch is thus defined as the horizontal distance between the respective piers in the transverse direction of the arch, which is typically parallel with the longitudinal axis of the viadUct; and the length of the arch as the length of the piers in the longitudinal direction of the arch, corresponding to the width of the viaduct. The overall height of the arch is the vertical distance between the arch floor or ground surface and the crown, which is an imaginary line extending along the length of the arch at the uppermost part of the soffit, typically equidistant between the respective piers.

The inwardly facing surfaces of the piers (i.e. the surfaces facing inwardly into the arch) thus define the generally vertical sides of the arch, while the two ends of the arch are often closed by freestanding walls defining a front entrance and, optionally, windows. Where the height of the arch permits, an additional floor (herein termed a mezzanine floor) may also be provided at an upper level.

Railway arches are usually damp and dirty and are often severely affected by rainwater which penetrates through the masonry and drips continuously from the soffut. The whole interior surface of the arch (piers and soffit) must therefore be lined so as to intercept the water and divert it, typically to narrow soakaways formed between the base of each pier and the adjacent edge of a concrete floor *.** slab, and/or to gutters arranged at or below the spring.

* Railway arches vary widely in their dimensions and in the geometry of the soffit, which for example ** may conform to a cylindrical surface, or may be flattened at the crown, or may be ellipsoidal with the minor radius at the crown. The spring may range in height from below ground level to many tens of * metres above ground level, although for most commercially usable arches it is likely to be of the orderof about im -15m above ground level. **** ** *

* In order to maximise the available space within the arch, it is important that the lining should conform as closely as possible to the surface of the soffit and piers while providing a continuous downward fall to carry water from the crown to the ground. Conventionally, the lining comprises overlapping corrugated plastics sheets which are screwed or nailed to horizontal battens fixed at spaced intervals to the soffit and piers. Each fixing passing through the corrugated sheets must be sealed to prevent water penetration.

In order to ensure their structural integrity, railway arches are subject to regular inspections, and in the United Kingdom a major inspection is typically carried out every ten years. This requires the sheets, battens and any interior structure to be entirely removed so that the masonry can be inspected and repointed or replaced as required. The arch is then re-lined with new materials. Over the years, numerous fasteners are inserted into the soffit and piers, and the repeated drilling damages the masonry while the fasteners corrode to leave voids which weaken the barrel and encourage water penetration.

The size and geometry of a railway arch often poses significant access problems when lining the soffit. For example, an average lined arch might be six metres in width and seven metres in height at the crown, with a height of four metres at the spring. Since the soffit curves away on either hand, it is impossible to support an ordinary ladder to safely reach the crown. A scaffolding tower is also inconvenient since it provides only a small working area and must be repeatedly moved as the work progresses. It is time consuming and difficult to drill multiple fixing holes into the soffit overhead and to accurately align the fixings with holes in the battens. Masonry is a heterogeneous material, comprising bricks and mortar joints of varying hardness as well as old, corroded fasteners and localised voids. It is therefore likely that the drill will wander or will need to be repositioned so as to avoid local obstructions.

GB 2 383 804 discloses an arch lining system comprising a plurality of overlapping tiles supported on a framework. The framework comprises a central, galvanized steel water deflection plate, which is fixed along the crown of the arch, and a set of spaced-apart frame elements, each comprising an outer, galvanized steel water deflection plate and an inner, aluminium extrusion, which are arranged in pairs to extend downwardly along the curve of the soffit in opposite directions from the central deflection plate on either side of the crown. The deflection plates are fixed to the soffit by means of *.... expanding bolts. Once the framework is in place, the tiles are fixed in horizontal rows between the * : *.: aluminium extrusions, so that the central portion of the lower edge of each tile extends downwardly behind the upper edge of the tile below, forming a continuous surface which sheds water. The ends * of each tile are sealed against the aluminium mouldings by means of neoprene gaskets, while any * : ..: 35 water falling onto the zone above the tile ends is diverted by the galvanized steel deflection plates to the central portion of the tiles on either side. * .*e * * S...

* The system of GB 804 advantageously provides for inspection of portions of the brickwork by *.: selective removal of the tiles, but it is not clear whether the system is able to accommodate variations 7/ in the curvature of the soffit without compromising the waterproof seal between the tiles and the aluminium extrusions.

Disadvantageously, the expanding bolts apply a point load in an inward direction away from the sofflt, which may dislodge individual bricks from the barrel. Moreover, the system of GB 804 relies on gaskets to seal the penetrations of the expanding bolts through the deflection plates, so that the integrity of the waterproof lining depends on the waterproof seal provided by each of the gaskets.

It is a general object of the present invention to provide an improved apparatus which may be used in installing a lining in an arched structure, particularly a railway arch.

Accordingly the present invention provides a panel and a lining comprising the panel as defined in the claims.

A novel framework comprising a plurality of elongate, flexible frame elements, which may be supported by stanchions at either side of the arch, is easily installed within an arched structure without inserting any fixings into the soffit or piers, so that the attendant problems of water penetration and structural damage are entirely avoided. Moreover, the flexible frame elements are adapted to be cut to length and re-joined as required and adapt automatically to the geometry of:the arch in which they are installed. Each installation can thus be accomplished using standard, interchangeable and largely re-usable components, and requires neither complex measurement nor customised parts.

The invention recognises that it is possible to provide a framework which is entirely self supporting -which is to say, a framework which is capable of transferring its own weight, plus the load imposed upon it by lining panels, lighting fixtures and the like, to the ground -but which nevertheless relies upon contact with the pre-existing masonry structure to provide it with rigidity and stability.

Alternatively, each flexible frame element may comprise locking joints which confer sufficient inherent rigidity to permit the frame element to be mechanically decoupled from the soffit in the installed position, which may be advantageous in ensuring compliance with applicable regulations. * * ****

* . * Since each flexible frame element does not need to provide the inherent rigidity and resistance to wind and other external loading required of an independent, freestanding structure, it may * * consequently be surprisingly long and small in profile compared with its load carrying capacity, * .: 35 making it relatively light in weight and cheap to manufacture. By engaging each flexible frame element pressingly against the soffit during installation, the whole lining may be accommodated within an envelope of no more than about, say, 50mm -75mm from the inner surface of the arch, * maximising the available space in the lined arch. * *. * S. /

The long, narrow, flexible frame elements are preferably supplied, bound together in pairs so as to form a rigid assembly which is easy to transport, and are easily installed without specialist access equipment by means of the novel installation tools which permit the majority of the installation work to be carried out at ground level. Once in place, the novel framework may be used to support a working platform or mezzanine floor which affords easy access for attachment of the lining panels beneath the soffit. After installation, the frame elements and panels may provide conduits and attachment points for wiring, small diameter pipework, lighting and power fixtures, and the like.

More specific objectives as well as further features and advantages will be understood from the following description in which some illustrative embodiments of the various elements of the invention are set forth, purely by way of example and without limitation to the scope of the invention, and with reference to the accompanying drawings, in which: Figs. 1 -12 illustrate sequential steps in the installation of a first embodiment of the novel system in a railway arch; Figs. 1 3A -1 3C. are respectively front, top and side views of a firstbaseplate; Figs. 14A -14C are end views respectively of a first stanchion, a first, unitary frame element incorporating a first, plastic deformation element, and the first frame element attached to the first stanchion; Fig. 14D is an end view of two first frame elements strapped together as supplied for transportation; Fig. 15 is a front view of part of the first stanchion; Figs. 16A and 16B are respectively a rear view and a side view of one end of the first frame element; Fig. 17 is a side view of part of the first stanchion; *q** * : * * Fig. 18 is a front view of part of a second, unitary frame element incorporating a second, plastic deformation element, slidingly engaged with a second stanchion; ** S * S S * S. * 35 Figs. 1 9A and I 9B are respectively a rear view and a side view of one hinge portion of the first frame element of Fig. 16A, showing the first, plastic deformation element after a first stage of deformation; S... * S *S.S

*. . Figs. 1 9C and 1 9D correspond to Figs. 1 9A and 198 and show the first frame element after a second * stage of deformation; Figs. 20A -20D show views corresponding to those of Figs. I 9A -1 9D of the second frame element of Fig. 18 after respectively first and second stages of deformation; Figs. 21A -21 E are respectively front, rear, side, first end and second end views of one rigid section of a third, articulated frame element incorporating a third, resilient deformation element, prior to assembly; Figs. 22A and 22B are respectively a side view and an end view of a spacer of the third frame element; Figs. 23A and 238 are respectively a side view and an end view of a pivot of the third frame element; Figs. 24A -24C are respectively rear, front and side views of one hinge portion of the third frame element after assembly, showing the third, resilient deformation element; Fig. 24D corresponds to Fig. 24C and shows the third frame element during installation; * Figs. 25A and 25B are respectively a front view and a side view of a jointing bar for use in joining together two short frame elements to form a longer frame element; * 20 Figs. 26A and 26B are respectively a side view and an end view of a second jointing bar with a cable tray; Fig. 27A is a cross-section of a first, preferred shield after extrusion and prior to rolling; Fig. 27B is a perspective view of the first shield after rolling; Figs. 28A and 28B are enlarged views respectively of the central attachment portion and of one longitudinal water guiding structure of the first shield; S...

Figs. 29 and 30 are cross-sections through the first shield attached respectively to the preferred * : * stanchion of Fig. 80 and to the preferred frame element of Fig. 85; S* S * ** * ..

Figs. 31A and 31B are respectively a front view and an end view of one end of a crown lining sheet; Figs. 32A and 32B are respectively a front view and an end view of a bracing strut;

S S. S

* Figs. 33A and 33B are respectively a side view and a front view of a bracket for use with the bracing strut;

F

Figs. 33C and 33D show alternative resilient deformation elements for use with the articulated frame element; Fig. 34A is a rear view of a first panel, in which the central portion is cut away to show both of its ends; Fig. 34B is a longitudinal section through the first panel at B -B in Fig. 34A; I0 Fig. 34C is a lower end view of the first panel as shown in Fig. 34A; Figs. 35A -35C are enlarged views of the lower end of the first panel as shown respectively in Figs. 34A-34C; Figs. 36A and 36B are enlarged views of the upper end of the first panel as shown respectively in Figs. 34A and 34B; Figs. 37A -37C are cross sections showing the cooperating upper and lower ends of two first panels after installation respectively near the crown, near the spring tine, and on stanchions adjacent the piers of a railway arch; Fig. 37D shows the rear water shedding surface of the panel in an alternative embodiment; Figs. 38A and 38B are respectively a front view and an end view of part of a replacement mounting flange for attachment to a cut end of the first panel; Fig. 39 is a section through part of an installed lining at the crown of a railway arch, parallel with the longitudinal axis of the arch; S...

Fig. 40 is a section through part of another installed lining lower down on the soffit of another railway **S* * * arch, parallel with the longitudinal axis of the arch; * S * * 35 Figs. 41-79 are deleted; and **.S.. * S

Figs. 80 -86 show particularly preferred embodiments of the stanchion and frame element for use * *** with the first shield, in which: S. * * Sb * S. Fig. 80 is a cross-section through the stanchion;

V

Fig. 81 shows a bracket assembly for attaching a bracing strut to the stanchion; Fig. 82 shows the bracket assembly attached to the stanchion; Fig. 83 shows a second bracket assembly for use in attaching a joist to the stanchion; Fig. 84 shows the second bracket assembly in use; Fig. 85 is a cross-section through the frame element; and Fig. 86 shows the frame element engaged with the stanchion.

It should be noted that small, repetitive details such as fixing apertures and hinge components are not shown in the views of Figs. I -12, and for full understanding, reference should be made to the individual component drawings in which these details are depicted.

Corresponding parts are indicated by the same reference numerals in each of the figures.

Referring to Fig. 1, a brickwork railway arch 1 comprises a barrel 2 which is supported by two parallel piers 3, 3' whose respective opposite, inwardly facing vertical surfaces 4, 4' are spaced apart by about 5.5 metres in the transverse (width) direction W of the arch to define the two sides of the arch.

The tower surface of the barrel forms an arched soffit 5 which intersects the sides 4, 4' of the arch to define two horizontal spring lines 6, 6' at a height of about 3.5 metres above the arch floor 7.

The soffit curves upwardly and inwardly as shown from the spring lines on either side of the arch towards an imaginary horizontal crown line 8 at its uppermost part, which extends longitudinally along the arch, parallel with the piers and equidistant between the two sides 4, 4' at a height of about 6 metres above the floor. The arch extends for a length of about 11 metres in its longitudinal direction L *..* * to a freestanding wail 9 at its rear end, and is open at its front end so that we can see whaVs happening. (Normally the front end would be closed with a corresponding wall or shutter.) The floor 7 comprises a concrete slab which is spaced from each pier by a narrow soakaway 10, 10'. S..S * * *.I* * * ** * * * * * S.

Overview Each flexible frame element can be a single length of top hat steel section, with the central U-shaped channel divided into portions by cut lines which leave the flanges intact to form deformable hinge portions. Alternatively the element can comprise a plurality of individual lengths of top-hat section pivotably riveted together.

The stanchions also comprise top-hat sections, preferably with tubular reinforcing portions, and are arranged in opposed pairs, one every two metres down each side of the arch. A length of extruded polyethylene shield is interposed between the rear wall of each stanchion (which faces the brickwork) and the pier. A tool is then mounted on each stanchion at floor level, and a mount on the top of the tool is pivoted about its axis (which is orthogonal to the plane of the pier) by releasing a ratchet until the mount lies on an axis slanting slightly down from horizontal towards one end of the arch. One end of the flexible frame element is releasably attached to the mount. Preferably, each flexible frame element is in two separate parts, and the corresponding end of the other part is attached to the other tool on the opposite stanchion. The two parts are then brought together manually in a generally horizontal plane and joined by a jointing bar in the centre of the floor of the arch, so that the frame element forms into an arched shape assisted by springs or plastic deformation elements at its joints.

A length of flexible shield is attached to the central web of the flexible frame element. It is then raised into a vertical plane, supported by the ratchets, and the tools are then driven simultaneously up the stanchions until the frame element (carrying the shield with it) engages pressingly against the soffit The mount can also be moved axially along its pivot axis so as to bring the frame element (top hat section) into nested sliding engagement with the stanchion, flanges against flanges. Continued upward movement of the tools engenders a hoop stress which conforms the frame element flexibly to the geometry of the soffit, after which the frame element is bolted to the stanchion.

The arch is thus lined with a series of hoops, each comprising a flexible frame element pressed against the curved soffit between the spring lines at either end and supported by a pair of vertical stanchions. In a development, the joints can be locked (e.g. by simultaneous or sequential resistance * * . projection welding in series), following which the tools can be lowered very slightly to relieve the hoop stress from the soffit. Panels are then attached between the hoops to form a complete water * shedding lining, with the lengths of flexible shield overlapped to define a dry zone covering the stanchions and the frame elements.

Once in place, the stanchions may be used to support a temporary working platform or mezzanine S...

* floor which affords easy access for attachment of the panels beneath the soffit, while the hoops S * * * . provide conduits and attachment points for wiring, small diameter pipework, lighting and power fixtures, and the like.

Simple baseplates In accordance with a first embodiment, installation commences by spacing out a series of mounting bases, which in their simplest form comprise flat attachment plates or baseplates 20 on the floor along the base of each pier. The baseplates are set out in pairs, one on either side of the arch and aligned in the transverse direction of the arch, at a spacing which corresponds to the length of a panel plus the width of a stanchion, as further described below. Conveniently, these components are dimensioned so that the baseplates are spaced apart by an easily measured distance, which in the example shown is 2 metres. The first pair of baseplates are arranged adjacent the front end of the arch, and the final (seventh) pair are arranged adjacent the rear wall 9 so that the spacing between the last two baseplates on each side is reduced to correspond to the length of the arch.

Referring to Figs. 13A -13C, each baseplate 20 comprises a flat steel plate 21 which is bent upwardly to form an angled portion 22 at its rear edge. A hole 23 is formed in each corner of the angled portion:for attachment of bracing wires as further described below. A short bracket 24 is welded to the plate 21 sothat its rear waIl 25 extends for a short distance beyond the angled portion 22, and its two side walls 26 are provided with fixing holes 27 and slots 28 which correspond respectively to the rear apertures 47 and front fixing holes 48 in the stanchions 40, as further described below.

The plate 21 is provided with fixing holes 29, and each plate is bolted to the floor slab 7 by means of two small expanding bolts inserted (preferably via the central pair of fixing holes 29) into holes drilled in the floor, so that the rear wall 25 is spaced about 5mm from the inner surface 4, 4' of the respective pier and overhangs the soakaway 10, 10'. The plates need only light fixing sufficient to locate the base of the respective stanchion adjacent the pier and to support the stanchion in an upright position during installation, as will now be described. Once the framework is in place, the fixings do not play any part in supporting it.

The initial fixing of the baseplates is the only stage at which any drilling is required, and also the only stage at which the arch needs to be measured so as to accurately locate components, since subsequent steps in the installation are all dependent on the position of the baseplates. Since the *: * principal measurement and all of the drilling is carried out on the floor, it is a very easy task : 35 compared with the conventional method of lining in which most of the work is done high up under the soffit. **0* * *

** * Once the baseplates are in position, support means are attached to the baseplates along each side * * * of the arch for supporting the flexible frame elements. Of course, each of the stanchions could alternatively include a suitable baseplate, so that it is fixed directly to the floor slab without the need for a separate mounting base.

Simple stanchions Referring to Figs. 14A -17, the support means comprise a plurality of first, rolled steel stanchions 40, each formed from a unitary length of mild steel plate formed into an elongate "top hat" profile comprising a central, U-shaped portion with a pair of oppositely directed lateral flanges 41. In this specification a stanchion is synonymous with a column, post or pillar.

Referring particularly to Fig. 15, each flange 41 is perforated with an array of panel fixing holes 42, 42' which receive self-tapping fixing screws for the attachment of lining panels 200 to the stanchion, as further described below. The panel fixing holes 42 are arranged in groups, the groups being spaced apart in the vertical (longitudinal) direction of the stanchion by a distance di. The corresponding groups of fixing holes 208 and slots 209 in the panel flanges 205 are spaced apart in the vertical direction by a repeat distance d2 (Fig; 36A), in which d2 = (d1 -(di / n)) wherein n is a whole number. This provides a fixing system in which the vertical position of each panel is finely.' adjustable according to the principle of a Vernier scale in increments of (d1 I n) with one coincidenàe' (providing a pair of aligned fixing holes) occumng at a distance of(d2.n), i.e. every(n -1) groups of holes 42.

The four fixing holes 42 within each group are spaced apart in the horizontal or transverse direction and in the vertical or longitudinal direction of the stanchion 40 by small distances, which in the vertical direction are not a factor of the increment (d1 I n) and so provide for still finer vertical as well as horizontal adjustments in the position of the panels 200 between the increments (di I n). Each panel can thus be fixed in any required vertical position.

In addition to the panel fixing holes, each flange 41 is provided with a series of regularly spaced * 30 rectangular apertures 43, and a further series of regularly spaced elongate apertures 44 with rounded ends. * *

The rectangular apertures 43 receive the projecting teeth 471 of the drive pinion 470 of the first *:*. installation tool 300, as further described in due course, so as to form a rack, while the flanges 41 : 35 provide an installation tool mounting structure which receives the mounting mechanism 301 of the installation tool so as to releasably mount the installation tool for sliding movement up and down the ** **** stanchion 40. The rack can also be used to support shelving or pallet racking arranged at the sides of ** * the arch. * * * * *e

The elongate apertures 44 provide windows which are so dimensioned and positioned that at least one of each diagonal pair of panel fixing holes 78 in the corresponding flange 71 of a first frame element 70 (visible in Fig. 16A and further described below) when attached to the first stanchion 40 (as shown in Fig. 14C) coincides, either with a rectangular aperture 43 or with an adjacent elongate aperture 44. The longitudinal spacing d3 between alternate panel fixing holes 78 in the first frame element also corresponds to the spacing between the fixing holes in the panel flanges according to the Vernier principle, so this arrangement ensures that every respective coincidence between the corresponding fixing holes in the frame element flange and in the panel flange is available for attachment of the panel to the frame element, with the fixing screw passing through the corresponding aperture 43 or 44 in the stanchion, when the frame element is attached to the stanchion as shown in Fig. 14C.

Referring particularly to Fig. 17, the central, U-shaped portion of the first stanchion comprises a rear wall 45 and two side walls 46, each side wall being provided with a series of rear apertures 47 adjacent the rear wall 45, and with frame element mounting or attachment means comprising two series of front fixing holes 48, 49 adjacent the respective flange 41.

The rear apertures 47 provide fixing points for the attachment of bracing wires and bracing struts as well asfor attaching the stanchion to the baseplate, as will shortly be described. They are spaced apart from the flanges 41 by a sufficient horizontal (transverse) distance to avoid the corresponding U-shaped portion of the first frame element when it is inserted into the stanchion, as most clearly seen in Fig. 60.

The front fixing holes 48, 49 of each series are spaced apart in the vertical (longitudinal) direction by a distance d4, corresponding to the longitudinal spacing d5 of two corresponding series of fixing holes 79 in each corresponding side wall 76 of the first frame element 70 (Fig. 16B), wherein d4 = (d5 -(d5 / n)) and n is a whole number.

This provides another fixing system on the Vernier principle, defining a range of positional adjustment * 30 between the frame element and the stanchion such that respective ones of the fixing holes in each senes 48, 49 are brought consecutively into alignment with corresponding ones of the fixing holes 79 * : * in the first frame element 70, each consecutively aligned pair of holes defining a through-hole for receiving a bolt 50 (Fig. 14C) for attaching the frame element to the stanchion, as the first frame *: element 70 is displaced axially along the first stanchion 40 through the incremental distance (d5 I n). * *

By way of example, where d5 = 35.0mm and n = 10, d4 = 31.5mm, providing one coincidence every (d.n) = (d5.(n -1)) = 315mm at an incremental axial displacement of no more than 3.5mm from any * given axial position of the frame element relative to the stanchion. -,

Whereas the corresponding two rows of apertures 79 in each side wall 76 of the first frame element are aligned in parallel, the corresponding front apertures 48, 49 of the first and second senes of the first stanchion are spaced apart by a longitudinal (vertical) distance d6 = (d5 /2). This doubles the number of repeat coincidences between corresponding apertures in the first frame element 70 and first stanchion 40, providing one coincidence alternately in the first series 48 and second series 49 of front fixing holes for every ((n -1)12) fixing holes 79 of the first frame element 70, i.e. spaced apart by a distance ((d4.n) I 2), for any given incrementally displaced position of the first frame element 70.

Of course, the relative spacings d4 and d5 could be reversed.

In a simple form, the two cooperating elements are thus provided with respective first and second series of apertures spaced apart respectively by the distance x and by the distance (x ± y), so that corresponding apertures of the first and second series are brought consecutively into alignment by relative axial displacement of the two elements through the incremental distance y. Preferably however, y = (xln) wherein n is a whole number, providing a large number (which may be many times n) of repeat coincidences with a very small and consistent increment throughout the full range of axial movement, in accordance with the Vernier principle described.

Installation of simple stanchions Referring to Fig. 2, each stanchion 40 is first cut to length as required using an angle grinder or the like so that it extends in its installed position to just below the spring line 6, 6'. A length of shield material 149 (further described below) is then attached to the rear wall 45 of the stanchion so that it extends from the bottom of the stanchion to about half a metre above the top of the stanchion, and the stanchion is then placed over the bracket 24 of the respective baseplate 20 (which fits slidingly between the side walls 46) and attached by means of bolts passing via the rear apertures 47 and front fixing holes 48 through the fixing holes 27 and slots 28 respectively. Once mounted on the baseplate, the rear wall of the stanchion extends into the small gap between the rear wall 25 of the bracket and the inner surface of the pier, so that the stanchion is supported in a vertical position just above the upturned rear edge' 22 of the bracket with the flanges 41 facing inwardly into the arch and * : * the shield sandwiched between its rear wall 45 and the pier. This allows water to run down between the inner surface 4, 4' of the pier and the shield 149, behind the rear edge 22 of the bracket and * t *, .: straight into the soakaway 10, 10'.

*..,: 35 Once in position, each stanchion (other than those at the front and rear of the arch) is braced against *::: :* rotational movement about its base parallel with the plane of the pier (i.e., prevented from toppling * : over in the longitudinal direction of the arch) by means of two small galvanised steel tension cables 67, one on either side of the stanchion, each being attached at its upper end to one of the rear apertures 47 close to the top of the stanchion and at its lower end to a galvanised turnbuckle 68 fixed to one of the holes 23 in the baseplate of the adjacent stanchion. The turnbuckles are tightened to tension both cables, while the stanchion is checked for verticality by means of a plumb-bob or, conveniently, a spirit level with a vertical vial. Any water running down the cable will drip off the tumbuckle into the soakaway at its base.

Referring also to Figs. 32A -338, the front and rear stanchions on either side of the arch are braced to their respective adjacent stanchions by means of a horizontal bracing strut 60, 60'. Each bracing strut comprises a tubular body 61 with a long internal thread 62 at each end, the rear bracing struts 60' having a shorter body. A series of external collars 63 are spaced apart near each end so as to prevent water from running horizontally along the strut in front of the shields. One end of the strut 60 is attached loosely to the upper end of the stanchion 40 by means of a bolt passing through one of the rear apertures 47 to engage the thread 62. The other end of the strut is attached to an elongate stud 64 which is welded to a bracket 65 having elongate fixing slots 66 which are dimensioned to allow it to be bolted to any adjacent pair of rear apertures 47 of the adjacent stanchion in any axial position along the stanchion. Once the bracket is attached and the thread 62 is engaged with the stud 64, the body 61 is rotated to advance it along the stud and adjust the spacing between the two stanchions, and once the end stanchion is upright, the bolt at the other end of the strut is tightened.

After the installation of lining panels as further described below, the panels will also support the stanchions in vertical alignment The stanchions 40 are now restrained in the longitudinal direction L by the bracing wires and struts and outwardly in the width direction W by the piers, so their only freedom of movement is now by rotation of the upper ends of the stanchions inwardly in the width direction W, away from the piers and into the arch. This movement is resisted prior to installation of the flexible frame elements by the small expanding bolts at the base of each stanchion. Once the flexible frame elements are fixed to the stanchions as will now be described, and during the process of installing them, their load (including the hoop stress applied during installation, and the load placed on them after installation by the lining, lighting fixtures etc.) braces the upper ends of the stanchions 40 outwardly in the width direction W towards the piers, so that the entire framework is stabilised and rigidified without *.I.

attachment to the masonry of the arch at any point. It is then impossible for the framework to collapse * : * under load, provided that its component parts are of adequate strength. ** . * * * * **

Preferred stanchion and frame element * I *. The top-hat configuration of the stanchion advantageously provides a rack for sliding/rolling *. : engagement by the tool, and the flanges provide attachment points for the panels, while the body of * the panel extends rearwardly of the flanges so that the flanges define the approximate plane of the interior surface of the finished arch lining. The central U-shaped recess also receives the frame / element and functions as a cabling channel. However, top-hat section may be vulnerable to buckling at higher slenderness ratios. It is therefore the particular object of one aspect of the invention to provide a stanchion which presents two lateral, oppositely directed flanges flanking a central recess, but which has improved axial compressive loadbearing capacity compared with a plain top hat section.

Referring to Figs. 80 -86, a preferred stanchion 600 (Fig. 80) is roll-formed from steel strip to form an elongate profile defining a central recess 601 with a pair of oppositely directed lateral flanges 602, the edges of the strip being continuously welded at the joint 603. The central recess comprises two spaced-apart rear walls 604, 605 and two side walls 606 arranged between the rear walls and the flanges. Each of the flanges defines a respective tubular section 607 (by which is meant a portion closed in cross-section), while the rear walls define a third tubular section 608. Advantageously, each of the side walls 606 comprises two layers of steel, which may be rigidified by spot welding them together, the mounting holes 609 for attachment of the flexible frame element being penetrated through both layers. The tubular flanges 602 and the tubular rear wall portion 608 resist local buckling, stiffening the section and greatly increasing its axial loadbearing capacity so that it is suitable for use in supporting a mezzanine floor.

The rear tubular section is penetrated by spaced-apart apertures 610 which receive the curved end 620 of a first bracket element 621 (Fig. 81). A cooperating second bracket element 622 óarrying a stud 624 is inserted into an aligned aperture 611 in the tubular flange 602, and the two bracket elements are bolted together (the bolt engaging in a threaded hole 623 in the first bracket element 621 and extending through it into the mounting hole 609) so as to fix the stud 624 to the stanchion as shown in Fig. 82, the stud then being used as required for attachment of a bracing strut 60 or cable 67.

A joist (not shown) may be attached to the stanchion using a pair of brackets 630 (Fig. 83), each having a vertical array of fixed studs 631 and threaded holes 632, the studs 631 being inserted into the mounting holes 609 in the double thickness side walls 606 so as to rapidly provide a satisfactory shear connection which is secured by only two bolts inserted via adjacent mounting holes 609 into corresponding adjacent threaded holes 632 in the brackets. The vertical web of the joist (not shown) is received between the two brackets, while the central recess 601 of the stanchion remains available . for cables 629 as shown in Fig. 84. The brackets 630 are waisted 633 so as to leave the flanges 602 * : clear to receive the mounting portions of the panels and accommodate lateral variations in stanchion spacing. ** * * * S

* The rear tubular section 608 is provided with two grooves 612 to receive the ribs 155 of the S...

* attachment portion of the first shield 150 (Fig. 28A) in snap-fit relation, as shown in Fig. 29. *.** * * S... *. S

S S *S w

Fig. 85 shows a preferred, one-piece flexible frame element 640 having a generally top-hat configuration with corresponding grooves 641, which similarly receive the ribs 155 of the shield 150 so as to retain it in snap-fit relation as shown in Fig. 30. The holes 642 for attachment to the preferred stanchion are formed through the grooves 641, which are cut away to receive rectangular nuts 643 (or rectangular headed bolts) as shown in Fig. 86, so that the frame element nests inside the stanchion 600, flange against flange.

Flexible frame elements Each flexible frame element may comprise a continuous, flexible metal or plastics section or profile (i.e. an elongate element with a uniform cross-sectional profile), such as an I-beam, a top-hat section, a square or rectangular hollow section, or the like, which has sufficient resistance to axial compression that it is capable of flexing to conform to the curvature of the soffit without collapsing axially under load. Alternatively, it may comprise a plurality of rigid, non-compressible portions joined in series by hinge portions. The latter arrangement is preferred since each hinge portion may then be arranged to prevent the formation of a reflex angle on the inner side of the frame element, i.e. the side facing inwardly into the interior space of the arch. (If a non-jointed, continuous, flexible, e.g plastics; profile were used, then it would need to have sufficient flexibility to bend outwardly to conform to the curvature of the soffit at its minimum radius. If the same profile were used on another arch with a much larger radius, then its flexibility could give rise to a risk of local buckling followed by catastrophic inward collapse of the arch lining, e.g. vertically downwardly at the crown. A hinged frame element, i.e. comprising rigid sections joined by hinge portions, would be usable in both arches as long as the hinges were arranged to substantially prevent the formation of a reflex angle.) The rigid portions and hinge portions may comprise integral parts of a unitary length of material, in which case the frame element may be manufactured at relatively low cost (conveniently in mild steel by laser cutting) and may be suitable for one-time installation or, with care, for re-use for a limited number of times. Alternatively, a fully re-usable element may be assembled from individual, jointed sections. Long frame elements may also be cut to make shorter elements, and short lengths may be joined together to make longer elements.

Referring to Figs. 14B -17, a first flexible frame element 70 comprises a unitary length of rolled mild * * steel utop hat" section, having a central, U-shaped recess portion with a pair of oppositely directed lateral flanges 71, in which the central, U-shaped portion is divided by means of a laser cutter to * define a flexible series of rigid portions 72 joined end-to-end by the flanges 71, which are left intact so * that they form a plastically deformable hinge portion 73 adjacent each cut. (Each rigid portion is 6.9*..

* "rigid" in the sense that it resists buckling under axial compression, although if desired it may admit of slight deflection in order to more closely conform to the curvature of the soffit. It is also possible for each rigid portion to be slightly curved rather than straight as shown.) The laser cutter produces cut lines of minimal thickness, so that the adjacent cut surfaces 74 which define the ends of each respective pair of rigid portion remain substantially in abutment to limit the range of pivotal movement at each hinge portion 73 to define a maximum angle 8 of about 1800 between the respective adjacent rigid portions on the inner side of the frame element, i.e. the side which faces away from the soffit This substantially prevents the formation of a reflex angle on the inner side of the frame element, which ensures that the arched configuration of the frame element cannot fail by localised buckling inwardly and downwardly away from the soffit. The maximum angle 8 of 180° also allows two frame elements 70 to form a rigid straight-line configuration when they are bound together flange-to-flange for dispatch from the factory, which makes them easy to handle prior to installation. Moreover, it allows adjacent rigid sections 72 to be vertically aligned along each stanchion below the spring line in their installed position.

Of course, rather than laser cutting, the frame element could be manufactured by conventional cutting or stamping/pressing. In order to bring the cut surfaces 74 into closer abutment, part of the rear wall 75 or side walls 76 which together comprise the central, U-shaped portion can be pressed or stretched to form a slight bulge at each cut line prior to cutting and then pressed back again afterwards, or local portions of the cut surfaces can simply be pressed together after cutting. It is also possible to press locahsed areas of adjacent rigid portions together so as to define a maximum angle 8oflessthan 180°.

The central, U-shaped recess portion of the frame element is adapted to be slid ingly received in the central, U-shaped recess portion of the first stanchion 40 during assembly so that once the frame element 70 reaches its installed position, in which the rear wall 75 is pressingly engaged against the soffit (adjacent each hinge portion) for at least some or, preferably, most or all of the length of the frame element, it can be bolted directly to the upper part of the first stanchion 40 as shown in Fig. 14C, with the flanges 71 lying against the flanges 41 of the stanchion.

Each pair of adjacent rigid portions 72 are pivotable during installation about their respective hinge portion 73 through a range of movement which is preferably limited in the outward direction by the abutment of the cut surfaces 74 and both restrained and limited in the inward direction by a plastic deformation element as further described below, so as to define an obtuse angle 0 between them on 1.1* ** * the inner side of the frame element. This permanent flexibility allows the frame element 70 to be * * raised into its installed position beneath the soffit so that, once it contacts the soffit, it may be urged against the soffit so as to conform to its upward and inward curvature, defining a self-supporting * arched configuration which transfers the load of the frame element to its respective first and second ends 77, which in turn are supported by the respective stanchions 40 extending upwardly from the I.....

* ground on either side of the arch. Once in its installed position, the frame element 70 does not need * to be supported at any point other than at its respective ends 77, although it may be further rigidified **** *. * * S S * and stabilised in the longitudinal direction of the arch by the attachment of bracing struts and/or panels between adjacent frame elements as further described below.

The rigid portions 72 are independent of each other so that they can adopt a different angle at each hinge portion 73, enabling the frame element 70 to conform to the curvature of any soffit, irrespective of its shape, and also to adopt a more acute angle at the spring line where it departs from the stanchion.

Since each flexible frame element 70 in accordance with the first embodiment is stabilised and rigidified by compressive hoop stress and by frictional contact with the soffit, it is unnecessary and undesirable to provide means for locking each of its rigid portions 72 in fixed angular or rotational relationship to the next. This permanent flexibility simplifies the frame element and also makes it easy to remove it and re-use it, as well as enabling it to conform to the curvature of the soffit as it is installed. The frame element of the first embodiment is thus only suitable for use in contact with an existing, arched soffit, and would not provide the rigidity required for a freestanding structure, independent of an existing arch or tunnel.

In alternative embodiments, means are provided whereby, after the frame element has been pressingly urged against the soffit so as to conform flexibJy to the curvature of the soffit as described above, the hinge portions may then be locked, following which the frame element may be slightly lowered so as to mechanically decouple it from the soffit while still retaining its arched configuration.

The flanges 71 form the inner side of the first frame element 70 which faces away from the soffit in the installed position, and each flange is provided with panel attachment structure (panel attachment means) comprising two rows of panel fixing holes 78, which are adapted to receive self-tapping screws and are arranged in diagonal pairs as shown so as to cooperate with the corresponding fixing holes in the panel flanges according to the Vernier principle as discussed above with reference to the first stanchion.

Each rigid portion is provided with support attachment means (stanchion attachment structure) comprising two rows of stanchion fixing holes 79 in each of its side walls 76, which are adapted to cooperate with the corresponding front fixing holes 48, 49 of the first stanchion forming an adjustable S...

* attachment system according to the Vernier principle as described above. This enables the first and * : ** second ends 77 to be slidingly adjusted in very small increments relative to the stanchions during installation so as to bring the rear wall 75 pressingly into abutment with the soffit, and then to be *: * attached to the stanchion 40 so as to support the frame element 70 in the installed position.

S

*S **..

* Since stanchion fixing holes 79 are provided in each rigid portion, rather than just at the ends 77, the * *.* frame element 70 may be divided by cutting it with an angle grinder or the like so as to form two 55* *5 * * S S * ** / shorter frame elements, and the cut ends of each frame element may thereafter be attached to the support means.

Preferably, the cutting (and joining of shorter elements, as described below) is done in the centre of a rigid portion, so that for reliability the hinge portions are always formed at the factory and not by the user. Indicia 80 are provided on the outer surface of the rear wall 75 of each rigid portion 72 to indicate the correct cut line.

The rear wall 75 of each rigid portion 72 is also provided with means for releasably attaching the frame element to an installation tool, comprising two oppositely directed pairs of keyhole slots 81, 81'.

When the rigid portion is cut by the user, one pair of slots 81 or 81' is left on each cut half, which then forms the end 77 of the frame element for attachment to the tool. In the example of Fig. 16A, the end 77 of the frame element terminates at a position corresponding to one of the cut tines, proving a terminal rigid portion 72' half the length of the others, which is attached to the tool during installation.

Each frame element is supplied from the factory with one such half length terminal rigid portion 72' at each end, so that the frame element can either be cut to length or used as supplied.

It is important to ensure that the frame element is able to bend at each respective hinge portion 73 as it engages the soffit, so as to avoid straight portions which depart from the curvature of the soffit.

One way of achieving this would be to resiliently bias each pair of adjacent rigid portions away from a straight line configuration, i.e. towards an inwardly bent configuration. However, to facilitate easy handling and transportation, it is preferable for each frame element to be biased towards (or supplied in) a straight line configuration in its rest position.

In order to achieve both of these objectives, preferably each hinge portion is provided with means which readily permits a first, small degree of bending inwardly into the arch, but which resists further bending until a substantially greater torque is applied to the joint. This means that as the frame element is progressively bent into its installed configuration (such as during attachment to the installation tools), as each hinge portion reaches its first extent of bending, it begins to transfer torque to the rigid portions on either side, so that all of the hinge portions are bent to the first, small extent, before the applied torque increases to the extent necessary to bend any of them further. Since all of * .** * the hinge portions are thus placed in an initially bent configuration when they contact the soffit, they are more readily bent to a furtherextent necessary to bring all of the rigid portions into abutnientat their ends with the soffit. ** , * * S

* Of course, it is not essential for every one of the rigid portions to abut the soffit after installation, since *SS*SS * the load on the framework will bring each frame element progressively into contact with the soffit at * .. its outer ends, ensuring that it remains stable even as it flattens slightly at the crown to accommodate * 40 any slight settling or movement after installation. p.

Referring to Figs. I 9A -I 9D, rather than cutting completely through the central, U-shaped portion at each hinge portion, the cut is preferably interrupted to define a plastic deformation element 87 in the rear wall 75 which forms the outer side of the first frame element 70 in the installed position, attached to the respective rigid portions 72 at each end and adjacent and spaced apart from the respective hinge portion 73.

(For the avoidance of doubt, in this specification the term "plastic deforrriation element" means "plastically deformable element", and not "a deformation element made from plastics material"; whereas the term "plastics" or "plastics matenal" refers to polymer material. Preferably, the plastic deformation element is made integrally with the frame element, e.g. from mild steel.) In the first frame element 70, the plastic deformation element 87 comprises a pattern of cuts (conveniently made by a laser cutter) similar to that used when forming the diamond shaped steel mesh commonly known as "expanded metal" or "expamet".

Each plastic deformation element is progressively plastically deformed by elongation during installation as the obtuse angle 8 between the respective adjacent rigid portions reduces. The cut lines in.the centre of the plastic deformation element are closer together than those at the ends, defining a weaker, initial deformation region 88 which is deformed to a first, minor extent as shown in Figs. 19A -19B by application of relatively little torque to the respective hinge portion. The remainder of the plastic deformation element is deformed to a second, relatively greater extent as shown in Figs. I 9C -. I 9D, only by application of relatively greater torque.

In its maximally deformed condition (perhaps slightly beyond the position shown in Figs. 19C and 1 9D), the plastic deformation element 87 prevents further bending and so defines a minimum, limiting angle 8. Once deformed, the plastic deformation element 87 will also provide a degree of resistance to bending in the reverse direction, so that it tends to hold the flexible frame element in its arched configuration which makes it easier to remove and re-install it without fatiguing the hinges.

Referring to Figs. 18 and 20A -20D, a second unitary, flexible frame element 90 is formed similarly to the first frame element 70 from a unitary length of mild steel "top hat" section. Each flange 91 has two rows of panel fixing holes 98, which (unlike those of the first element 70) are spaced apart by a *....: distance d7 which is a factor of the length of each rigid portion 92, so as to form a continuous pattern * 35 from one rigid portion 92 to the next. As described above, the distance d7 is related to the spacing d2 * between adjacent fixing holes in the corresponding flange of the panel 200 to form an adjustable panel attachment system on the Vernier principle.

*S ** S* * S In Fig. 18, the second frame element 90 is shown with its central U-shaped portion slidingly engaged in the corresponding central U-shaped portion of a second stanchion 100. Each flange 101 of the second stanchion has a series of rectangular apertures 102 spaced apart by a distance d8, which are adapted to be engaged by the movement mechanism of a second, alternative installation tool as further described below. Each flange 101 also has a row of outer fixing holes 103 and a row of inner fixing holes 104, the holes in each row being spaced apart by the same distance d7 as the panel fixing holes 98 in the second frame element so as to receive self tapping screws for attachment of the panels to the stanchion.

The second frame element 90 is narrower than the second stanchion 100 so that the outer fixing holes 103 on each flange of the stanchion are exposed when the second frame element 90 is attached to it in the position shown. The vertical panels can thus be fixed to the outer row of fixing holes 103 in this region, and to the outer fixing holes 103 or inner fixing holes 104 over the rest of the stanchion.

A second plastic deformation element 94 is arranged adjacent each hinge portion 93 of the second frame element 90, and functions similarly to that of the first frame element. It is formed by continuous, interlaced cuts in the outer waIl 95 defining a relatively smaller, weaker central region 96 which deforms to a first, small extent as shown in Figs. 20A -20B on application of a first, small torque.

while the remainder of the deformation element 94 is relatively larger so that it is substantially deformed to a second, greater extent only on application of substantially greater torque, as shown in Figs. 20C -20D. Deformation increases proportionately to the applied force.

In alternative embodiments, the plastic deformation element can be arranged as a crumple portion which is compressed as the angle 9 reduces. It can also be a separate element, e.g. wrapped around the pivot pin of each discrete rigid portion of an articulated, re-usable flexible frame element, one embodiment of which will now be described.

Referring to Figs. 21A-24D, a third, fully re-usable flexible frame element 110 comprises art articulated assembly of individual rigid portions 112 joined end-to-end by pivots 113.

Similarly to the first and second flexible frame elements, each rigid portion 112 comprises a short length of galvanised or passivated zinc plated mild steel formed into an elongate "top hat" section comprising a rear wall 115 and two opposed side walls 116, which together form a central U-shaped * portion, and two oppositely directed lateral flanges 111. The rear wall 115 forms the outer side of the frame element which engages the soffit, while the flanges 111 form the inner side of the frame * 35 element which faces away from the soffit in use. The end walls 114 of each rigid portion cooperate to * form abutment surfaces which limit the obtuse angle 0 formed between each pair of adjacent rigid portions on the inner side of the frame element to a maximum of 180° as shown in Fig. 24C. **S** * *

* *** Panel fixing holes 118 are provided in each of the flanges 111, while stanchion fixing holes 119 are * * provided in each side wall 116 so that the frame element can be attached to one of the stanchions 40 as already described above. Two oppositely directed pairs of keyhole slots 121, 121 are provided in each rear wall, and indicia 120 indicate the correct position at which the rigid section 112 may be cut to define two separate, half length terminal sections, each of which may subsequently be attached to the first installation tool and thereafter to one stanchion 40 as one end of a separate frame element Similarly to the first and second frame elements, each third frame element 110 is supplied with two half length terminal rigid sections (not shown) so that it is ready for use.

The side walls 116 of each rigid portion 112 are joggled inwards to form an outer pair of hinge brackets 122 at one end of the rigid portion and an inner pair of hinge brackets 123 at the other. The rigid portions are assembled together at the factory by means of a steel rivet 124 which passes through the respective outer and inner hinge brackets to form a pivot pin about which the two sections can pivot. The pivot pin 124 passes through a spacer 125 (made for example from plastics material) which maintains the separation between the inner pair of brackets 123 so as to rigidify the resulting pivot or hinge portion 113.

After assembly, the ends of the pivot pin or rivet 124 lie flush with or slightly inward of the side walls 116 as shown, so that the assembled frame element can be slidingly engaged in the stanchion 40 in the same way as the first and secOnd frame elements already described.

The rear wall 115 of each rigid portion 112 is cut at each end to define a bracket 126 which is bent inwardly towards the flanges 111. A resilient deformation element, comprising a helical steel tension Spring 127, is attached between each pair of adjacent brackets 126 so that it extends between the two adjacent rigid portions 112 in spaced relation to the hinge 113. The spring is accommodated by a cutout 128 in the rear wall so that it can be positioned as far as possible from the hinge portion 113.

As the adjacent rigid portions 112 pivot about the hinge 113 during installation (Fig. 240), the spring 127 elongates proportionately to the applied torque, so that it transfers torque from one rigid portion to the next in a similar way to the plastic deformation elements already described, ensuring that each hinge portion is angled during installation.

Preferably, the spring 127 is arranged so that, in the 180° or rest condition of the respective hinge portion, its coils are almost or completely closed and it is only lightly engaged with the brackets 126, * as shown in Fig. 24C. This means that relatively little torque is required to pivot the rigid portions 112 * : *.: to a first, minor extent, before the spring more strongly resists further deformation until substantially greater torque is applied. Each resilient deformation element 127 thus biases the third frame element *. lightly towards a straight line configuration in its rest condition, as shown in Fig. 24C. * S. IS *S

* The tension spring 127 or hinge portion 113 or rigid portions 112 may be provided with an extension * **. limiting arrangement (for example, a short steel cable or bar inside the spring, or a sleeve around the spring, or an arm which extends from one rigid portion to abut against the other) which defines a minimum, limiting angle e and so prevents over-extension of the spring. Instead of a tension spring, the resilient deformation element might comprise a helical compression spring arranged between two abutting surfaces of the respective adjacent rigid portions 112 -for example, between the rear wall of one rigid portion and a projecting arm of the other rigid portion -in which case the compression spring will define a minimum, limiting angle 8 at the point at which its coils are fully closed. A resilient, rubber or plastics spring could be used instead of or in addition to a coil spring. Alternatively, the resilient deformation element could comprise a leaf spring, or any other type of spring, such as a torsion spring arranged around the pivot pin or spacer so that its projecting ends engage the respective rigid portions 112. Of course, the articulated, third frame element 110 could also be made without resilient deformation portions.

Instead of resilient or plastic deformation portions, each separate pivot or integral hinge portion could include some other means providing a reaction force or resistance to pivotal movement -for example, a friction device arranged at the pivot.

Referring to Figs. 33C and 330, each resilient deformation element could be formed by a plastics or rubber block instead of a spring. Fig. 33C shows a resilient deformation element 770 cut from an * extruded section of resilient material, e.g. rubber, having a central hole 771 to receive the pivot, two wings 772 which engage the respective rigid portions of the frame element, and a stem 773 supporting a compressible top cap 774 which extends between the frame element and the soffit, so as to cushion the abutting ends of the rigid portions against small movements of the soffit. The stem extends between the ends of the rigid portions of the frame element, which are recessed to accommodate it; it may resiliently bias them apart so as to initiate the angular deflection between the two sections in use.

Fig. 33D shows an alternative resilient deformation element 780 extruded from resilient plastics material and having insert portions 781 for insertion into apertures in the central wall of the U-shaped section of each respective rigid portion; a corrugated, resiliently extensible portion 782 which resists angular deformation at the joint; and a stem 783 which may be used to urge the rigid portions apart as installation commences, or to insulate them where welding is intended.

Of course, if preferred, the pivots 113 could be arranged to permit the user to divide the frame element and re-join it at each hinge. Preferably however the hinges are permanent and are made in * * . the factory so as to avoid any risk of incorrect assembly, and the frame element is divided if required by cutting through a rigid portion where indicated (120). ** * * * * * **

The pivots 113 allow the third frame element to be installed, removed and re-installed as many times as necessary, so it can be re-used each time the framework is removed for renovation of the arch. * *** * * ** * * I I * **

In contrast, where the first and second, unitary frame elements are made from mild steel or perhaps from aluminium, they must be treated with care so as to avoid repeatedly stressing their unitary hinge portions, which could result in metal fatigue and ultimately failure of the hinges. The relatively great length and small profile of each frame element may make it difficult to install it without repeated flexing; however, this difficulty is ameliorated by the presence of the deformation elements which limit angular displacement at each joint, and is preferably overcome by use of the novel installation tool, as further described below.

It is envisaged that articulated frame elements (assembled from separate sections) will be preferred for long term use in arches which are frequently inspected, whereas unitary frame elements (which can be manufactured at low cost, for example, by re-working a roll formed or pressed, top hat section with a production laser cutting machine) will be preferred in one-time installations which are not likely to be disturbed, or in situations where economy is more important.

It is also envisaged that those using the novel system on a regular basis will keep a stock of frame elements and divide and re-join them as necessary for each job.

Referring to Figs. 25A and 25B, a jointing bar 130 comprises a rigid, U-shaped section having a rear wall 131 and two side walls 132, eachside wall having a series of holes 133 which correspond to the fixing holes (79, 119) in the side walls of each rigid section of the first, second and third frame elements. Two frame elements may be joined end-to-end to form a longer frame element by arranging the jointing bar 130 inside the central, U-shaped portions of the respective, half-length terminal rigid sections of the two shorter frame elements so that they abut in the centre of the jointing bar, and bolting the two frame elements respectively to the jointing bar via the cooperating holes.

Shield Referring to Figs. 27A -30, a first, preferred shield 150 comprises an elongate profile extruded for example from high density polyethylene. A central, attachment portion 151 extends along its longitudinal axis L, flanked by two lateral water shedding portions 152, each having a front surface 153 which faces away from the soffit in use and an opposite, rear surface 154 which faces towards the soffit in use.

* 35 The attachment portion 151 forms a resilient clip structure having ribs 155 which engage in corresponding grooves in the stanchion and frame element to attach the shield, either to the rear *.,..: surface of the stanchion (Fig.29), or to an outer side of the frame element (Fig. 30) so that the shield * stays in place as the frame element is raised into an installed position beneath the soffit. The clip also **0** defines grooves 156, which receive the ribs 155 of a second length of shield, the clip structures ** * * * * * ** deforming resiliently so that the two lengths can be clipped together in nested relation, such as at the overlap just above each stanchion.

The front surface 153 of each of the water shedding portions 152 includes an outer zone 162 having a plurality of water guiding structures 157 which extend in parallel with the longitudinal axis L so that they face towards the rear, water shedding surface of the adjacent panel in use. Each structure comprises a group of fins with narrow tips 158. The fins extend away from the surface 153 and curve slightly away from the attachment portion, defining an incurved portion 159 and a plurality of crevices 160, all of which tend to trap water droplets so as to encourage them to travel longitudinally along the water guiding structure while preventing them from travelling laterally across the front surface 153 towards the attachment portion.

The outer edge portions 161 of the water shedding portions curve back towards the soffit so that the outer zones 162 are urged away from the soffit and into contact with the rear surface of the panel.

The fins are most effective near the crown, where the shield is almost horizontal, so that any water droplets that run onto the downwardly facing front surface of the shield are likely to run or drip off the narrow tips 158 of the fins onto the rear surface of the panel, which channels them down towards the ground. -..** A pair of first and second inner zones 163, 164 are arranged between each, outer zone and the attachment portion. After extrusion, the inner zones 163, 164 are flat as shown in Fig. 27A. The extrusion is then passed between a pair of mating, heated rollers which impress a pattern of corrugations 165, 166 forming oblique water guiding structures into each of the inner zones. In the first inner zones 163, the corrugations 165 extend obliquely downwardly and outwardly away from the attachment portion as shown, while in the second inner zone 164, the corrugations 166 are reversed so as to extend obliquely upwardly and outwardly as shown.

The oblique corrugations become increasingly effective as the shield becomes progressively more steeply angled towards the vertical. In the position shown, any water droplets reaching the first inner zone 163 are guided outwardly away from the attachment portion by the corrugations 165.

Preferably, two lengths of shield are arranged, both in the orientation shown, with a short gap at the crown of the arch which is covered by a short capping extrusion (not shown), which may be a thin extrusion with downwardly extending edges. This makes it easy to remove and re-install the frame *....: element without disturbing spinal cabling running along the crown between adjacent frame elements, * 35 with the capping extrusion being left behind on top of the cabling. However, if preferred, a single *: * length of shield can be attached along the whole length of the element It will be appreciated that the other end of the shield will then be in the upside-down orientation to that shown, so that the *.S.S* * directions of the corrugations 165, 166 are reversed. The corrugations 166 of the second inner zone 164 are then effective to guide any water droplets which reach that area, outwardly away from the * * * 40 attachment portion. ** * * S * * S.

The central wall of the attachment portion has thick corrugations 168 which form a compressible structure 167, which is arranged in use between the flexible frame element and the soffit. The soffit of a railway arch exhibits very small movements (in the order of 1mm -2mm or so) as trains pass over it, and the corrugations provide sufficient stiffness to react the hoop stress against the soffit, yet are capable of collapsing so as to provide lost motion which cushions the frame element and mechanically decouples it from small movements of the soffit. Instead of corrugations, an inherently compressible material could be used, such as a foamed plastics material, an elastomer, or the like.

When the frame element 70 is raised into an installed position beneath the soffit 5 as shown in Fig. 40, the attachment portion of the shield is thus positioned between the rear wall of the frame element and the soffit. The compressible structure cushions the frame element 70 against the soffit 5, so that the shield is not damaged as the ends of each rigid section of the frame element press upwardly and outwardly against the soffit. The lateral water shedding portions are spread out on each side during installation of the panels 200 so that they are urged resiliently into engagement with the channelled rear surfaces of the panels as shown, providing a dry zone beneath the shield.

(For the avoidance of doubt, references in this specification to the frame element being engaged against or in contact with the soffit are to be construed as including this arrangement, in which a shield is interposed between the frame element and the soffit.) Preferably, the shield material is supplied on a large diameter roll, so that as it is unrolled it naturally adopts a curved configuration which helps it to conform to the curvature of the frame element.

It will be noted that the shields and panels do not rely on any compressive seal for their effectiveness, but rather on the respective downwardly and outwardly oriented water channelling surfaces which prevent water from travelling laterally towards the frame element This provides great tolerance between the various system elements so that the system remains effective, irrespective of the accuracy of installation or the curvature of the soffit Of course, compressive seals or the like could be provided if preferred. The water shedding surfaces could also be micro-structured so as to define an energy bamer for droplets moving transversely, e.g. transitioning between the Wenzel state and the Cassie-Baxter state. * U. * S **.

Alternative shield elements 149 and 140, each comprising a flexible plastics or elastomeric extrusion * S having lateral water shedding portions with longitudinal water guiding corrugations 143, and a central * . attachment portion comprising an adhesive stripl 45 for attachment to the frame element and a compressible structure 147 for absorbing movement between the frame element and the soffit, are *S 4 *S* * 1 shown respectively in the installed position at the crown of the arch in Figs. 39 and 40. In alternative embodiments, the shield could be made from other plastics material such as polyester, or from thin galvanized steel, aluminium or the like. In further alternative embodiments, the central attachment portion can have a rounded external surface which tends to deflect the frame element and shield away from any old fixings projecting from the soffit as the frame element is raised into position, and which also resiliently clips over the central recess portion of the frame element and cushions it against the soffit. A springy cap made from galvanized steel or hard plastics material could also be clipped over the rear surface of the shield to deflect it away from old fixings projecting from the soffit, which are more preferably removed prior to installation.

Installation of flexible frame elements The nominal required length L1 for each flexible frame element can be calculated roughly, based on the width W of the arch according to the formula L1 = ((irW)/2) + 2m, which resolves to L1 = (1.57W) + 2m. This gives the correct length to span a semi-cylindrical soffit with a 1 m overlap for fixing at each end.

Alternatively or additionally, a table can be supplied in which the columns are headed by representations of the arch configuration (egg-shaped, cylindrical, flattened, etc.), the rows correspond to the width of the arch, and the body of the table gives the required length of the flexible frame element for each combination.

In the example shown in Figs. 1 -12, each unitary, flexible frame element 70 is about lOm in length, about 50mm deep (between its rear wall and its flanges) and about 110mm in width (between the outer edges of its flanges). It is relatively rigid in its width direction, but due to its length it is quite floppy in its depth direction, which presents a potential difficulty in transporting it and raising it into its installed position, several metres above ground level, while avoiding uncontrolled movements which could cause unnecessary flexing and weakening of its integral hinge portions.

Referring to Fig. 14D, this problem is avoided prior to installation by supplying the flexible frame elements 70 in pairs which are arranged front to front (flanges together) and banded together by plastics ties 178. Since each frame element is preferably constrained to form a maximum angle on its inner face (facing away from the soffit in use) of 180° at each joint, the two elements together thus form a substantially rigid, straight assembly in which they are easily handled and transported to the *** ** point of use without damaging them. * .

Referring to Figs. 3-8, each frame element 70 is then preferably installed by means of a pair of first installation tools 300, by which means each frame element 70 is easily raised into pressing * engagement with the soffit and then secured in its installed position while avoiding any unnecessary ***SS a flexing of its integral joints. S... * . S. S

I -S.

Referring particularly to Fig. 3, each first installation tool 300 comprises a releasable mounting mechanism 301 for mounting the tool for controlled movement towards the soffit; a frame element attachment mechanism (302, Fig. 5) for releasably attaching one end of the flexible frame element 70 to the tool; and a movement mechanism 303 for controlling the movement of the tool up and down towards and away from the soffit. In the embodiment shown, the releasable mounting mechanism 301 is adapted for releasably mounting the tool in sliding engagement with the flanges 41 of one of the stanchions 40, while the movement mechanism 303 comprises a mechanism for manually raising and lowering the tool up and down the stanchion.

In addition, each tool 300 preferably includes a separation adjustment mechanism 304 for moving the respective end of the attached frame element 70 towards and away from the respective stanchion 40; and a pivot mechanism 305 controlled by a releasable ratchet mechanism, which permits the frame element 70 to be raised from a substantially horizontal orientation to a substantially vertical orientation after attachment to the tool while restraining the frame element 70 against downward movement.

Once all the stanchions 40 are in place and the bracing struts 60 and bracing cables 67 have been installed, each of the two installation tools 300 is mounted on the base of a respective one of a first pair of stanchions 40 on opposite sides of the arch, the ratchet is released by pulling the detent ring 423, and the pivot mechanism 305 is pivoted in whichever direction offers more room, so that each respective frame element attachment mechanism 302 extends horizontally or, preferably, slightly downwardly towards the floor of the arch. The separation adjustment mechanism 304 is adjusted by means of its removable handle 396 to provide a gap between each end of the frame element and the respective stanchion 40, which accommodates the ends of the shield 149 as the frame element is raised as further described below.

A first pair of frame elements 70 are then placed on the ground and separated by cutting the ties 178.

One frame element 70 is then attached at a first one of its ends 77 to the attachment mechanism 302 of a first one of the tools, so that it extends along the ground away from the respective stanchion 40 (Fig. 3).

The installer then walks with the second end 77 of the frame element in a wide arc towards the e*0 second tool, so that the frame element is progressively bent into an arched configuration while it lies on the ground, and attaches the second end 77 to the attachment mechanism 302 of the second tool 300 as shown in Fig. 58. Bending at each hinge portion is controlled by the respective plastic * deformation elements as described above. * *e *

* Once the two ends 77 of the frame element 70 are attached to the two respective tools 300, the * *.* midsection of the frame element is raised a short distance off the ground and supported on building :: 40 blocks 11 or the like. A length of shield material 149 is then cut from the roll and fitted over the outer (i.e. the soffit-engaging) face of the frame element 70, so that it extends along the whole length of the curved frame element between its two ends. (Fig. 4.) The frame element 70 is then raised to a substantially vertical plane as shown in Fig. 5, while the attachment mechanism 302 of each tool pivots about its pivot mechanism 305. The ratchet mechanism cooperates with the pivot mechanism 305 to allow upward movement while preventing the frame element from falling back downwards in either direction, and cooperates with a safety detent bolt 421 (further described below) to automatically lock the pivot mechanism 305 of each tool when the frame element 70 reaches its vertical position.

This makes it relatively straightforward for two people to raise the flexible frame element 70 by pushing it upwards, one at each end, or even for a single person to raise it by pushing it initially as close to the middle as they can reach, then closer to one end, relying on the two ratchets to hold it up once it reaches a more upright position. The maximum 180° angle 0 between adjacent rigid portions 72 prevents the frame element 70 from bending outwardly to contact the stanchions 40, so that it settles into a stable, fairly even, arched configuration in which it is safely supported in a vertical plane, clear of the stanchions, as shown in Fig. 54..

Alternatively, for installation by one person, the midsection of the frame element 70 can first be raised as high as possible off the ground and supported on a short freestanding ladder. A rope or plumb-bob cord 12 is then passed through the two centre keyhole slots 81, 81' in the rear waIl 75 of one rigid portion 72 nearest to the middle of the frame element 70, and the frame element is raised to the vertical position by pulling the rope or cord 12 in the longitudinal direction of the arch. This can also be accomplished without effort by passing the rope 12 through a block which is fixed between the upper ends of two distant stanchions, or by using two ropes passing through two blocks fixed respectively to the upper ends of two distant stanchions.

Of course, if preferred, each tool could also be adapted to provide a geared mechanism or the like for raising the frame element to an upright position, although the applied torque will then be substantial.

Once the frame element is locked in the vertical position by the detent bolts, with the shield 149 -extending down between the frame element and the stanchion at each end, a handle 550, comprising a short steel tube with a threaded inner end and a hole in its outer end, is screwed into the left-hand : (upward) drive socket of the movement mechanism 303 of each tool. In the example shown, a short length of cord 13 is also attached to the hole in the outer end of each handle so that the handle can * be operated from the ground against the restoring force of its return spring. (Fig. 5.) * SSSI** * The two handles 550 are then operated (either simultaneously by two people or alternately by the same person) by pulling on the cords 13 to raise each tool 300 carrying the frame element 70 up the S. S * *S * *5 two stanchions 40, until the outer face of the rear wall 75 of the frame element (cushioned by the shield 149) contacts the soffit 5.

The ends of the shield material 149 attached to the frame element 70 are thus removed progressively from the gap between the frame element and the stanchion by the upward movement of the tools.

They are then trimmed as necessary, and the upper end of the shield material 149 previously captured behind each stanchion 40 is led up beneath the shield material 149 on the frame element as shown, so that the two lengths overlap to provide a water-shedding joint. (Fig. 6.) The removable handle 396 of each separation adjustment mechanism 304 is then operated to move each respective frame element attachment mechanism 302 carrying the respective end 77 of the frame element 70 outwardly, so that the central U-shaped portion of each end of the frame element is slidably engaged in the central U-shaped portion of the corresponding stanchion 40, with the flanges 71 of the frame element abutting against the flanges 41 of the stanchion, as shown in Fig. 60.

If necessary, each frame element 70 can now be adjusted for verticality by means of a plumb-bob 14 suspended on the cord 12 which is attached to the midpoint of the frame element. A second cord 15 is stretched between the respective supporting columns 40 beneath the frame element. The position of the frame element is simply adjusted by pulling on the plumb-bob cord 12 in the required longitudinal direction of the arch until the plumb-bob 14 is in alignment with the bottom cord 15. (Fig. 6.) The handles 550 are then operated again so as to raise the tools 300 and the frame element 70 slidingly upwardly relative to the stanchions 40, forcing the frame element pressingly upwardly and outwardly against the soffit 50 into its final, installed position. This upward movement induces a compressive hoop stress between the ends 77 of the frame element, forcing each rigid portion 72 of the frame element outwardly against the soffit 5 and sandwiching the shield 149 between the frame element and the soffit along its whole length while urging the upper ends of the stanchions outwardly against the piers.

Each end 77 of the frame element 70 is then attached by bolts 50 to the upper end of the stanchion above the tool, as shown in Fig. 14C, so that the residual hoop stress is maintained by the stanchions acting in compression. Due to the adjustable attachment system already described, * * based on the Vernier principle, the frame element 70 is attachable in virtually any vertical position on the stanchion 40, and the degree of overlap is of little significance, so the system is very tolerant of * errors in measurement or calculation. (Fig. 7.) *** * * If the plumb-bob cord 12 was looped through the keyhole slots in the frame element, it can now be S...

* * *.. recovered by pulling on one end so as to be re-attached to the next frame element. Alternatively, it a. S

SS a *S

could be looped through a small wire or plastics widget (not shown) attached to the keyhole slots, so as to make it easier to recover.

The frame element attachment mechanism 302 of each tool is then detached from the frame element and the handle 550 is engaged in the right-hand (downward) drive socket and operated to bring the tool back down the stanchion 40, after which the mounting mechanism 301 is released and the tool is removed from the stanchion. The remaining frame elements 70 are then installed in the same way. In its installed position, each of the frame elements 70 is thus jammed up tightly against the brickwork of the soffit so that it conforms flexibly to the curvature of the soffit 5, forming a self supporting arched configuration in which it is supported only by the two stanchions 40 on opposite sides of the arch, while being rigidified and also restrained against movement in the longitudinal direction of the arch by frictional contact with the soffit. (Fig. 8.) By use of the novel tool, the flexible frame element may thus be handled and installed simply and efficiently while avoiding unnecessary flexing of the joints. Moreover, there is very little need to work above ground level during installation of the framework. All that is required is a relatively short ladder which gives access to the upper end of each column for fixing the bracing struts and cables, overlapping the lengths of shield material, bolting the frame element to the column and operating the tool, which is preferably operable mostly from ground level as described. Thus (apart from a few bolts and a spanner) there is no need to carry tools or materials up or down the ladder.

Of course, the tools are equally suitable for use in installing the articulated frame elements 110.

Crown jointing element Referring to Figs. 26A and 26B, a second jointing element 650 functions similarly to the jointing bar (Figs. 25A -25B), comprising attachment portions 651 for attachment to additional fixing holes (not shown) which are arranged in the side walls of the preferred flexible frame element 640 (Fig. 85) between its flanges and mounting holes 642. The attachment portions are arranged inside the frame element and spaced apart so as to define an open space communicating with a cutout 652. Raised wings 653 extend outwardly in use from a flat, central joining plate 654 in the longitudinal direction of the arch, and receive a mounting flange 661 of a cable tray 660 which functions in the same way as S.: the struts 60, but also supports cabling running along the crown of the arch, which passes over the * : * plate 654, as well as lighting fixtures which can be suspended from the tray. This cabling can branch off to pass through the cutout 652 and along the recess of the frame element, in the manner of a vertebral nervous system. Cabling can also pass along the frame element across the crown, in which case it is routed beneath the raised wings 653 and supported by bendable fingers 662 of the cable tray. 0s** * S *s*S ** . * * .

S

Advantageously, the cabling may be removed from the central recess of the frame element and left hanging from the frame elements on either side, following which the cable tray is disconnected and the frame element may be lowered (with the jointing element 650 in place). Any cabling passing over the central plate 654 is left in place, hanging from the crown of the arch between the two adjacent frame elements. Preferably, the shield is arranged in two lengths with a short gap at the crown, covered by a crown shield which extends above the spinal wiring. This enables the frame elements to be removed and replaced one by one without disconnecting the wiring.

Desirably, each frame element is divided into two halves, which are attached separately, one to each of the tools, and then brought together and joined in the middle of the floor with the jointing element 650. This makes them easier to handle and halves the amount of space required to bend them. The two tools may be synchronised as described below so as to ensure that all of the jointing elements 650 are aligned at the crown.

Desirably, bendable fingers can also be cutout from the frame element adjacent each hinge portion, which extend part-way across the central recess in spaced-apart relation so as to retain cabling in position, allowing the cabling to be inserted by twisting it between the fingers.

Joists The stanchions may be used to support horizontal joists, providing a mezzanine floor, in which case the stanchions are dimensioned accordingly and the joists and floor are installed once the framework is in place and before the lining panels are attached, so that the floor provides a working platform which affords easy access to the whole of the soffit up to the crown.

Alternatively, where it is not intended to install a mezzanine floor, smaller stanchions are used, and lightweight temporary joists 181 may be releasably attached to the stanchions to support a temporary working platform giving access to the soffit.

Referring to Fig. 9, for installation of a floor or working platform, a bracket 180 is preferably first bolted to the upper end of each stanchion 40. Each bracket 180 may comprise a flat plate which is inserted into the central U-shaped portion of the frame element 70 inside the stanchion 40 and is * * bolted through corresponding holes in the two abutting side walls 76, 46 (Fig. 14C). It may be * : * installed at the same time as the frame element 70 is bolted to the stanchion, so that all three elements are fixed together simultaneously by the bolts 50. The bracket 180 may provide adjustable *: * attachment holes, both for attachment of the bOltS 50 and for attachment of the joist 181, so that the *. * * bracket 180 can be adjustably positioned on the stanchion 40 and/or the joist 181 can be adjustably positioned on the bracket 180. Alternatively, a two-part bracket can be used which provides positional *.** * ** adjustment between its parts. ** . * * * * S.

Conveniently, each temporary joist 181 comprises a telescopic assembly comprising two hollow, box section or inverted, U-section or top-hat section aluminium end portions 182, in which an aluminium centre portion 183 is telescopically received. The centre portion 183 has slots 184, and the three parts are retained in sliding, adjustable relation by bolts 185 which pass through the slots. Each end portion 182 has a fixing hole 186 at its outer end, closer to its base than to its upper (horizontal) wall.

Each temporary joist 181 is first lifted at one end and slid over one of the brackets 180, which is received between the side walls of the joist so that the upper wall of the joist sits on the bracket, and then pivotably attached to the bracket by means of a bolt via the fixing hole 186. (Fig. 9.) The other end of the joist is then raised off the ground (either by lifting it directly or, perhaps, by a modified attachment to the installation tool) and attached at its second end to the corresponding bracket 180 on the upper end of the opposite stanchion 40. The assembly telescopes to accommodate the changing length of the joist. By fixing two or three joists side by side and then laying boards or planks across them, a stable working platform or floor 187 is quickly created which affords easy access to the soffit up to the crown. (Fig. 10.) The framework (comprising principally the flexible frame elements 70 and stanchions 40) can be used to support panels 200 or sheeting to form a waterproof lining, and can also be used either with or without a lining or shield elements to support lighting fixtures, pipework, racking and the like.

Stub stanchions After the joists and floor are installed, the flanges of each stanchion are clear from floor to spring line so that panels can be mounted on the stanchions all the way up, irrespective of whether the beams and floor remain in place. Preferably the beams are installed at least about 1.5m below the spring line (i.e. the line at which the curved soffit meets the vertical piers). This means that if it is intended to install a mezzanine floor, then there are two options after initial installation of the stanchions: i) the flexible frame elements are installed first using the tools, and then the mezzanine floor is installed. * ***.

* ii) the mezzanine floor is installed first, and then the tools are mounted on the portions of the stanchions projecting above the level of the floor, and the frame element is laid out on the mezzanine *. .: floor, and attached to the tools as before, then raised into a vertical position and installed in the same :* way as before, except that the tools will travel only a very short distance before the flexible frame element engages against the soffit. **** * * ** * * * a * S.

In either case, the flexible frame elements can be removed again in the same way, without disturbing the mezzanine floor.

If it is intended to install the mezzanine floor higher than the critical level of about I.5m below the spring line, then an alternative procedure can be adopted.

The stanchions and mezzanine floor are installed as before. Then a short, vertical, stub stanchion is attached by means of a bracket to each end region of each beam. The stub stanchion is at least about 1.5m in height and extends vertically up from the beam to meet the soffit at its upper end. So each stub stanchion is horizontally displaced from the pier by a distance determined by the angle of the soffit, the height of the mezzanine floor and the height of the stub stanchion. The tools are then mounted on the stub stanchions and the flexible frame elements are installed as before, with the flexible frame element being formed into an arched configuration while laid out on the mezzanine floor. The soffit is thus lined with an upper set of panels attached to the flanges of the flexible frame elements and of the stub stanchions, so that this upper set of panels terminate at their lower edges adjacent the mezzanine floor to define low side walls. The piers can be lined with a lower set of panels which are installed behind the floor and terminate at their upper edges at the upper ends of the main set of stanchions adjacent the soffit. Similar stub stanchions can also be set in from the*.

edges of the floor for lining an arch in which the soffitextends up from floor level.

Corrugated sheets are arranged to intercept water falling from the soffit in the zone behind the stub stanchions and direct it down behind the lower set of panels.

Water dripping down the upper set of panels is guided, either into a gutter supported on the beams just behind the stub stanchions (the gutter having sloped edge portions that extend between the adjacent stub stanchions to intercept water falling from the lower edge of each panel), or onto the corrugated sheets which extend down behind the upper edges of the lower set of panels.

When the arch is due for inspection and maintenance, the mezzanine floor can remain in place while the panels are removed. Each panel can be removed individually from anywhere in the arch, with the mezzanine floor providing a working platform for repairing the brickwork behind. While the panels are removed, any wiring remains in place in the U-shaped channels provided by the frame elements and the stanchions (as do any sockets and light fittings attached to the flanges), which are preferably left in place unless the brickwork behind them has to be accessed. This makes it much easier to do *SS*S * regular inspections without disrupting the internal arrangements of the arch. If necessary, the flexible * 35 frame elements attached to the stub stanchions can be removed (and later re-installed) by reversing the installation procedure, without removing the mezzanine floor.

* * * .,** * S * * . **.* Finishing the crown S. * * 40 S. Where it is intended to install lining materials, preferably a crown shield 190 is now attached between the frame elements 70 along the crown line, with its edges lying beneath the shields 149 on the flanges 71 of the frame elements, so as to intercept water falling from the crown of the arch and channel it downwards onto the panels 200 on either side.

Referring to Figs. 31A -31B, the crown shield 190 comprises a corrugated plastics sheet, the corrugations being arranged to run in the transverse (width) direction of the arch so that they channel water downwards along the curve of the soffit.

Preferably, a bracing strut 60 or 60' is also arranged between each pair of adjacent frame elements at the crown, so as to additionally stabilise the frame elements in the longitudinal direction of the arch. (Where panels are to be attached to the frame elements, the panels will also provide stability.) Each bracing strut 60 is installed underneath the crown shield 190 along the crown line so as to support the centre of the crown shield, and the crown shield is optionally attached to the bracing strut by cable ties 191 passing through holes in its edges, beneath the protective shield 149, as shown in Fig. 10 and in cross-section in Fig. 39.

In a development, the bracing strut can be adapted to define a cable channel for retaining cables, pipework and the like running between the adjacent frame elements at the crown line, in which case the adjoining longitudinal panel edges can be spaced apart along the crown line to leave a space for the cabling, which is finished by a longitudinal cover strip.

Panels Referring to Figs. 34A -37C, a first panel 200 comprises a body portion 201 made from waterproof, rigid, closed cell foamed plastics material (e.g. polyurethane, polyisocyanurate or expanded polystyrene), which is bonded to a substantially flat, planar front board 202 with bevelled upper and lower longitudinal edges 203, 222, whose substantially flat front surface 204 faces inwardly into the arch in the installed position. The board 202 can be made from cementitious material, calcium silicate, polypropylene, polyethylene or other fairly rigid plastics material, fibreglass, powder coated sheet steel, compressed cellulose or mineral particles, or any other fairly rigid material which is adequately strong and resistant to damp and which presents an acceptable internal surface 204. S. * *

* . : 35 Two steel flanges 205 are bonded, one at each end of the panel, between the body portion 201 and * the front board 202 so as to extend in the transverse direction of the panel between the upper * longitudinal edge 210 of the panel and the lower longitudinal edge 222 of the front board 202, which is spaced apart from the lower longitudinal edge 211 of the panel, which edges 210, 211, 222 will * * ** generally be horizontal in the installed position. The outwardly extending portion of each flange 205 * . * 40 forms an attachment portion 206 which is perforated with a diagonal pattern of fixing holes 208 and

I

slots 209, which are spaced apart in the transverse direction of the panel by a distance d2 so as to cooperate with the corresponding fixing holes in the respective flange of the stanchion 40 or frame element 70 according to the Vernier principle as discussed above, providing a positionally adjustable fixing system. The attachment portions 206 of the flanges are wide enough in the longitudinal direction of the panel to tolerate substantial variations in the spacing of the stanchions 40 and frame elements 70, so that each panel may overlap the respective flange of the frame element or stanchion to a greater or lesser extent as illustrated for example in Figs. 39 and 40.

The inwardly extending portion 207 of each flange may also be provided with second perforations, so that the front board 202 and flanges 205 can all be arranged in a mould before the body portion 201 is formed by injecting a pre-mixed plastics compound into the mould, which then expands through the second perforations to bond the front board 202 and flanges 205 together.

The rear, water shedding surface 212 of the body portion 201 is divided into a plurality of channels 213 which extend in parallel in the transverse direction of the panel to guide water falling from the soffit 5 or shields 149 onto the panel, downwardly from its upper edge 210 to its lower edge 211, while preventing it from travelling laterally beneath the shields 149. The base of each channel 213 (forming part of the rear, water shedding surface 212) diverges outwardly from the front surface 204 as shown and downwardly in the installed position towards the lower edge 211 of the panel, where it curves back, inwardly into the arch and towards the front surface 204 to form the outer, water shedding surface 214 of a lower wall 215, whose opposite (inwardly facing) surface 216 also curves inwardly (away from the soffit) in the installed position of the panel to define an elongate recess 221 between the lower edge 211 of the panel and the lower edge 222 of the front board 202.

The lower wall 215 is so arranged that its outer surface 214 and inner surface 216 are both inclined downwardly, irrespective of the angle of inclination of the panel in its installed position, as will be seen by comparing the relative position of the lower wall 215 in its installed position close to the crown of the arch (Fig. 37A) and in a vertical orientation adjacent one of the piers (Fig. 37C).

This ensures that water running down the water shedding surface 212 of the channel 213 will always drip vertically downwardly from the tip 217 of the lower wall 215. In order to prevent water from running laterally along the tip 217 of the lower wall in the longitudinal direction of the panel, each of the lands 218 which separate the channels 213 extends around the tip 217 of the lower wall to provide a nose 219 which always lies at the lowermost point of the lower wall 215 (cf. Figs. 37A, 37C).

* : The overall depth of the panel between each of its flanges 205 and the rear surface 220 of each of the lands 218 is slightly less than the depth of the frame element 70 between its flanges 71 and its * rear wall 75, so that the body portion 201 can be accommodated adjacent the soffit 5 in the space *: . 40 between the frame elements 70 (depending of course on the angular position of each panel relative to the frame elements) and only the relatively thin front board 202 extends outwardly of the flanges 71 of the frame element at the top and bottom of the panel. This allows the whole lining to be arranged very close to the masonry of the arch, maximising the usable space within.

The rear, water shedding surface 212 of each channel 213 terminates at its upper end in a shallow recess 223 which extends longitudinally for the whole length of the panel, proximate its upper edge 210 and generally horizontally in the installed position. Each land 218 tapers at its upper end to meet a shallow, faceted hump 224 which divides the floor of the recess 223 between each pair of adjacent channels 213. This ensures that water falling into the recess 223 will not travel laterally along it, but will rather be shed to one side or the other of each hump 224 and thus directed into the nearest channel 213. (The humps 224' at the ends of the panel face towards the centre of the panel) The upper wall 225 of the recess 223 extends generally in the outward direction towards the soffit (which is to say, outwardly towards the soffit rather than inwardly towards the arch) in the installed position of the panel to define an elongate protuberance 226 which (together with the channels 213, lands 218 and recess 223) also forms an integral part of the moulded body portion 201.

Referring particularly to Figs. 37A -37C, the attachment portions 206 are attached by self-tapping screws respectively, either to the flanges of two adjacent stanchiorts or to the flanges of two adjacent flexible frame elements, so as to support the panel 200 in an installed position in which it is inclined downwardly from its upper edge 210 to its lower edge 211, with its rear, water shedding surface 212 facing in an outward direction towards the sofflt 5 or the adjacent pier 3, 3', as illustrated for example in Fig. 40.

Preferably, installation commences with the bottom panels. Each panel is attached to the framework above the one below so that the flanges 205 of each panel abut the flanges of the stanchion or frame element adjacent the respective upper and lower bevelled longitudinal edges 203, 222 of the front boards 202, which edges respectively abut each other to define, either a wide groove (Figs. 37A, 37C) or a narrow interstice (Fig. 37B) or a groove of intermediate width, depending on the angle 02 defined between the inwardly facing surfaces 204 of the two panels 200.

The rear surface 220 of each of the lands 218 at the lower edge 211 of the panel is radiused about an axis defined by the bottom edges 221 of the flanges 205, so that the second panel may be * : * installed by inserting its lower edge 211 behind the upper edge 210 of the panel below, before rotating its respective upper edge 210 towards the soffit into its installed position, the radiused * surface allowing it to clear the soffit at its lower edge as it rotates. Since the front board 202 of the *: * upper panel then rests on the front board 202 of the lower panel, it is easy to support the upper panel dunng installation, and if preferred, it may be secured by means of only two fasteners, one at each * * . end either at mid-height or near to its upper edge. ** *

* e * 40 * .* Referring to Fig. 37A, two panels 200 are shown in their installed positions, close to the crown line 8 of a wide arch with a gently curving, flattened soffit, with their respective front surfaces 204 substantially aligned and their respective rear, water shedding surfaces 212 both inclined downwardly at a shallow angle 83 of only 2° below a nominal horizontal line H. (In Figs. 37A -37C, the upper panel 200 is denoted by the reference numeral 200' and the lower panel 200 by the reference numeral 200", purely to distinguish their relative positions.) The respective upper and lower walls 225, 215 of the two panels are so configured (as already described) that, even in this position, they interlock to shed water from the rear surface 212 of the upper panel 200' to the rear surface 212 of the lower panel 200", such that the respective rear surfaces 212 of the two panels form an effectively continuous water shedding surface, with the upper wall 225 and protuberance 226 of the lower panel 200" being received in the corresponding recess 221 of the upper panel 200' and the lower wall 215 of the upper panel 200' extending downwards into the recess 223 of the lower panel 200" as shown. In this configuration it is impossible for water to travel up out of the interlocking joint thus produced between the panels.

Referring to Fig. 37B, the two panels may be attached at any point adjacent the soffit or piers so that they are inclined downwardly at different angles of inclination as shown, whilst their respective upper and lower walls 225, 215 still cooperate to shed water from the rear surface 212 of the upper panel 200' to the rear surface 212 of the lower panel 200".

In the position shown in Fig. 37B, the rear, water shedding surface 212 of the upper panel 200' is inclined downwardly at a relatively shallow angle 03 of about 5° below a nominal horizontal line H, representing the position of the upper panel if it were attached, just above the spring line of an arch in which the soffit departs from the spring line at an exceptionally shallow angle. The lower wall 215 of the upper panel 200' is positioned vertically above and behind the rear, water shedding surface 212 of the lower panel 200", so that even in this extreme position, water dripping from the lower wall 215 will fall downwardly, behind the protuberance 226, upper wall 225 and rear water shedding surface 212 of the lower panel, so that the two panels again form an effectively continuous, water shedding surface.

In the position shown in Fig. 37B, the obtuse angle 83 between the upper and lower panels is about *.*S* * * 102°, while in the example of Fig. 37A, the corresponding angle 83 is about 177°, giving a range of * * 35 angular variation between the two illustrated positions of about 75°.

* * Preferably, the upper and lower walls 225, 215 of each panel are so configured that the obtuse angle 82 may be varied by at least 15° while still forming a continuous, water shedding surface between the *.. two panels, which degree of variation allows the panels to be adapted for use in most positions on * * 40 reasonably evenly curved soffits.

More preferably, the obtuse angle 82 may be varied by at least 700 as shown; and most preferably, the aforesaid angutar variation is possible, even where the rear, water shedding surface of the upper panel ties at a relatively shallow angle of only a few degrees below the horizontal, as shown, which permits each pair of panels to be installed at virtually any point on the internal surface of virtually any arch, irrespective of its geometry.

Referring to Fig. 37C, the upper and lower walls 225, 215 are so configured that the two panels may also be installed one above the other on the stanchions adjacent the pier at one side of the arch, with their rear surfaces facing the internal surface 4 or 4' of the pier and their respective front surfaces 204 in vertical alignment as shown, to form a vertical wall. In this position, the lower wall 215 is accommodated in the recess 223 with its tip 217 lying just above the shallow humps 224 (which is why they are shallow), while the protuberance 226 is received in the recess 221, so that once again, the respective rear surfaces 212 of both panels cooperate to form an effectively continuous water shedding surface.

In order to facilitate attachment of the panels to the stanchions adjacent each pier so as to form a vertical wall, as well as. to the frame elements around the soffit so as to form a curved ceiling, the front surface 204 of each panel is preferably flat and planar as shown; of course, if preferred, each panel could be curved for use exclusively beneath the soffit The foamed plastics body portion 201 and lands 218 provide a light weight, rigid structure which also thermally insulates the front surface 204, reducing condensation.

Rather than directing water into soakaways at floor level, the panels may be arranged to discharge water into gutters at the spring. The panels 200 can be attached to any supporting framework, and are not limited to use with the novel flexible frame elements. Instead of self tapping screws, the respective flanges may be adapted if preferred to receive special fasteners, designed for example so that they require only a quarter turn to install or release them. Such adaptations will be within the purview of those skilled in the art.

In alternative embodiments, the front board 202 could simply be a thin layer or coating attached to *... the body portion 201. It is also possible to make the panel in a single, unitary piece, without either * S. flanges or a front board. The two flanges could be combined into a single, embedded supporting * structure, or they could be integral with the front board, so that the panel comprises a foamed body *. : 35 portion with a metal front skin integral with the attachment portions. The panel could also be formed * ** in one piece, or with inserts or a separate front surface material, by structural reaction injection moulding, reaction injection moulding, blow moulding, twin sheet thermoforming, or any other suitable process. S... * . *5*S * S I **

Rather than being deep grooves moulded into the rear surface of the body portion as shown, the channels could be defined by shallow ribs or the like which are formed on the rear, water shedding surface; the body and attachment portions of the panel could then be made for example as a unitary plastics moulding, or from a single sheet of steel which is joggled at its top and bottom edges to form the upper and lower walls.

Of course, the rear, water shedding surface of the panel could also be formed without channels.

Referring to Fig. 37D, in an alternative embodiment, the lateral regions 750 of the panel adjacent the mounting portions 751 are formed with channels 752 which are arranged obliquely so as to run downwardly away from the lateral edge 753 of the panel and towards its lower edge 754; these slanted channels divert any stray water droplets away from the dry zone beneath the shield. In the main body of the panel, narrower lands 755 are formed with a chevron pattern of channels 756 which run obliquely downwardly and away from the centre line 757 of the land 755 towards the larger channel 758 on either side. The parallel channels 758 are aligned with the lateral edges 753 of the panel, which (like those of the foregoing embodiment) advantageously allow the panel to be cut along its transverse (top to bottom) direction between the lateral regions 750 to virtually any required * length, so as to fit between the final pair ofstanchions or frame elements. Any water falling onto the lands is diverted towards the main channel onthenearest side, which prevents lateral flow.

Each of the channels 752 and 756 may be relatively shallower at its upper end 752', 756' and relatively deeper at its lower end 752", 756", so that it functions to divert water towards its lower end, even when the panel is nearly horizontal.

In this embodiment, the mounting portions 751 are discontinuous, comprising a pair of tabs 751 at the lower edge of the panel and a corresponding pair at the upper edge (not shown). This leaves the flanges of the stanchion or frame element clear between the flanges, so that electrical boxes and the like can be attached directly to the flanges between the adjacent panels. The cosmetic covers (not shown) which cover the gaps between adjacent vertical sides of the panels are selectively provided with apertures to conform to the boxes.

Referring to Figs. 38A -38B, in order to allow each panel 200 to be cut to length along its transverse dimension if required, a replacement mounting flange 230 is formed from a single, folded sheet of * ***** * * mild or spring steel, having an attachment portion 231 similar to that of the panel 200 which extends *. : from a pair of resilient, spaced walls 232, 233, which are arranged to embrace the cut end of the * panel 200 with the front wall 232 lying over its front surface 204 and the rear wall 233 lying over the *:1 rear surfaces 220 of the lands 218, so that the double thickness attachment portion 231 then lies in the same position as the original flange 205 which has been cut away from the panel. * .*S * * *. ** * * ** * S.

After cutting the panel 200 to length, a thin scrap steel sheet (not shown) is first laid against the rear surfaces 220 of the lands 218 along the cut edge of the panel. The front wall 232 and rear wall 233 are then resiliently pulled apart (assisted by the separation of the two halves of the folded attachment portion 231) and forced over the cut edge of the panel, with the scrap steel sheet protecting its rear surface. Once the aligned end walls 234, 235 abut the cut end of the panel, the scrap steel sheet is pulled out and the rear wall 233 is tapped with a hammer so that sharp, intumed points 236 formed integrally with the rear wall 233 penetrate the rear surfaces 220 of the lands 218, locking the flange to the panel. Small screw holes (not shown) may also be provided so that the front wall 232 can be screwed to the front board 202 for added security.

Finishing the lining Refemng to Figs. 11 -12, the panels 200 are attached to the flanges of the stanchions 40 and frame elements 70, starting from the floor and working up towards the crown between the joists in a continuous sequence, so that each panel is interlocked with the one below. The final set of panels are cut to length and then fitted with replacement flanges as described above before being attached between the rear pair of stanchions and frame elements on either side of the arch.

Once the final rows of full panels have been placed on either side of the crown, the remaining longitudinal gap at the crown can be filled by a row of panels cut to fit along their longitudinal axes, or with two rows of cut panels which meet at the crown, with the lands being cut away if necessary to accommodate the bracing strut Alternatively, a gap can be left to accommodate cables and the like, in which case it is preferably covered by a removable cosmetic cover strip (not shown). Once lighting fixtures and other fittings are in place, the temporary joists can finally be removed.

After installation, each frame element 70 is kept dry by its shield 149, so that any water falling on the area above the frame element is diverted downwardly along the shield or sideways onto the rear, water shedding surfaces 212 of the overlapping panels 200, whose channels 213 prevent water from running back beneath the protective shields. The shields 149 extend around the end stanchions to cover the corners of the rear wall 9 (as well as the front wall, which is not shown), so that the front * *.. and rear walls can be finished, either conventionally or by means of another set of panels 200 supported if required on vertical, top hat section brackets screwed to the walls or attached at their ****S' * * upper ends to the rearmost frame element 70, to provide a complete, waterproof lining.

** * 35 : By providing an upper fastener and a lower fastener on each side of each panel 200, which are * " attached to the respective flanges 71 of the frame elements 70 on either side, each panel 200 acts as a rigidifying element or cross-brace which prevents movement of the respective frame elements in * the longitudinal direction of the arch. Once all the panels are in place, the lining forms an extremely * * 40 stable structure. The panels can be removed one by one for inspection and maintenance of the ( -j masonry, and when a major inspection is necessary, the entire lining and framework can be removed and replaced by reversing the installation procedure.

If required, the interstices or grooves between the longitudinal edges of the panels can be filled with mastic or with a compressible rubber or foam profile, but this should be unnecessary as long as they are arranged in close abutment, which is made possible by the adjustable attachment system described above.

Advantageously, the continuous U-shaped channels defined by the nested frame elements and stanchions and protected by the shields can be used as conduits to carry wiring and small diameter flexible pipework around the inside of the arch, while the flanges of the frame elements, stanchions and panels provide mounting points for sockets, lighting fixtures and the like. The gaps between adjacent panels at each frame element are preferably covered by cosmetic, plastics or metal cover strips (not shown) which provide access to the cabling beneath, the cover strips preferably being resiliently retained so that their outer edges are pressed outwardly against the inner surfaces 204 of the panels, providing an even finish at each joint which covers variations in spacing between the stanchions, frame elements and panels. Of course, if preferred, the panels could be arranged to abut at their vertical joints as well.

An alternative frame element comprises a plurality of rigid, mild steel top-har profile body sections, similar to those of the foregoing embodiments, joined together by hinge portions which are adapted to be locked in the installed position by simultaneous resistance welding. The shield material is electrically nonconductive (or has a nonconductive and heat resistant inner surface, such as a layer of woven glass fabric) and is resistant to the momentary localised heat of the welding operation. It may be made for example from a heat resistant plastics material.

Summary

In summary, a preferred embodiment provides a plurality of elongate, flexible frame elements, each * *, a protected by a flexible, waterproof shield and engaged frictionally against the curved soffit by hoop stress applied at either end, preferably by a pair of installation tools mounted on stanchions. Each * : : tool preferably includes a pivoting ratchet which allows the flexible frame element to be formed into * : 35 an arched shape on the ground and then raised into a vertical plane prior to installation. Each frame * element may comprise a unitary top-hat" profile with deformable hinges, each hinge having an * associated deformation structure which distributes bending forces evenly during installation. The frame elements may be fixed to the stanchions to support them at either end in their installed * . .. position, providing a self-supporting, arched framework which relies upon the masonry soffit for its * * 40 shape and stability. Alternatively, each frame element may comprise joints which are remotely locked in the installed position, allowing the frame element to be decoupled from the soffut The framework can be installed without specialist access equipment, and the stanchions may be used to support a temporary mezzanine floor made from modular, interlocking panels which provides access to the soffut for installaton of cooperating, flat lining panels, each panel preferably comprising a foamed plastics body with downwardly directed channels and interlocking upper and lower edges which cooperate to form an angularly adjustable joint.

Instead of the baseplates first described, a single steel beam or the like could alternatively be fixed horizontally along the base of each pier, each stanchion being attached at its base to the beam; alternatively, each pair of stanchions may be attached, one at either end of a beam arranged transversely across the floor of the arch, so that a suspended floor may be laid across the beams, in which case the beams and stanchions need not be bolted to the floor. The entire installation may then be accomplished without the use of a drill or nail gun.

Instead of or additionally to the use of shield material, each frame element and/or each column might be made with an integral shield portion which diverts water downwards to the ground and/or to the panels on either side. In the frame elements, the shield portion might also form the integral, plastically deformable hinge portions, which may then be located on the outer side of the frame element. For example, each frame element might comprise a flat strip of steel, aluminium or plastics material arranged adjacent the soffit, with a series of short, rigid box sections extending (integrally or in fixed relation) from its inwardly facing surface. The box sections may be flanged and may provide attachment means (e.g., screw holes or channels) for receiving the lining panels, which may have flanges as illustrated or alternatively for example may simply slot into the channels. The ends of the box sections may be spaced apart by a sufficient distance that they abut to define a minimum obtuse angle at each hinge portion. The whole frame element (or just the strip) may be galvanised, and the strip may be bent along each edge, inwardly into the arch and/or outwardly towards the soffit, so as to prevent water from running back along its inner surface. Such an integral frame element made from aluminium or plastics material may be very light in weight, and depending on the length and design of the flexible frame element and the availability of access equipment, it may be preferred to install the flexible frame element in low arches or tunnels without using the novel installation tools.

Alternatively, the element can be attached at one end and then engaged against the soffit by using just one tool at the other end. *

Of course, if (unusually) the arch is inherently dry, no shields are required.

*. . 35 The invention may be applied to low arches in which the soffit curves upwardly from the ground or from a short distance above the ground, as well as to round, egg-shaped or horseshoe-shaped tunnels and the like in which the soffit and the sides of the structure form a continuous curve, the * width of the floor being less than the width of the tunnel at its horizontal diameter. In such cases, the * 40 support elements (support means) may simply comprise steel plates bolted to the floor, or the two ends of a beam laid transversely across the floor, or alternatively brackets or the like attached above floor level to the inner surface or structural lining of the tunnel, so that the flexible element extends part way around the soffit from side to side of the tunnel or alternatively right around the curve of the tunnel to terminate at the floor at either end. The support elements may also comprise an integral part of a permanent tunnel lining, which may form a rack or the like for receiving the installation tool.

All of these support means may incorporate or accommodate a screwthread or other adjustment mechanism for forcing the ends of the frame element apart or together (depending on how far the frame element extends around the circumference of the tunnel) so as to induce a compressive hoop stress which urges it outwardly against the inner surface of the tunnel into its installed position. Two frame elements may also be coupled together end-toend by an expander which induces hoop stress. Such arrangements may be suitable for use for example in installing a waterproof inner lining in underground railway tunnels and station plafforms.

The novel framework may also be installed in inclined tunnels, such as escalator (moving staircase) tunnels in underground railway stations, in which case the stanchions and frame elements may be arranged, either vertically instepped relation or inclined normally to the axis of the tunnel, and may be supported additionally against downward movement by attachment to the structural lining of the tunnel and/or by additional bracing struts. Frame elements may also include pivotal joints so that the frame element at one end of an arch can be skewed to follow the end of the soffit where an arch is angled with respect to the longitudinal axis of the viaduct.

Wherever means are disclosed herein for performing a function, that means may comprise any arrangement which is capable of performing that function in its essential aspects as defined by the claims, and is not limited to the specific means described.

The locking structure can comprise any suitable arrangement for locking adjacent rigid portions of the frame element in the selected angular position.

The support elements (support means) can be any arrangement which supports the ends of the frame element securely in the installed position. *s..

S

In very simple installations, such as in low arches in which the floor comprises a soft ground surface, * .5*S.

* S each of the support means may simply comprise a steel stake driven into the ground, or a hole in the * 35 ground into which the respective end of the flexible element is placed (supported in its installed * ** * position hard up against the soffit) before the hole is filled with concrete. If preferred, the flexible element may be attached at one or both ends to a bracket which is bolted or otherwise secured directly to the structural lining which forms the inner surface of a tunnel, or to the masonry of a pier or S.,.

soffit, in which case the brackets may be left permanently in position when the lining and framework * are removed for maintenance of the structure. A stanchion or rack may be secured adjacent one or both brackets to receive the installation tool during installation of the flexible element The frame element attachment structure of the stanchion, and the cooperating mounting or attachment structure of the frame element, can be any suitable means, including holes, flanges, slots, lugs, portion of the stanchion or frame element or other feature whatsoever, whether limited to that function or providing that function in combination with another essential or inessential function, which facilitates the attachment of the frame element to the stanchion or other support means.

Preferably, the attachment means should allow the frame element to be vertically adjusted relative to the stanchion or support means during installation and prior to attachment.

The panel attachment structure of the stanchion can be any suitable means for attaching the panels, and need not comprise cooperating holes for receiving screws or other fasteners. For example, each frame element could provide a channel into which the edges of the panels or corrugated lining sheets can be inserted; alternatively, the frame elements could be adapted to allow the panels to be hooked on without the use of fasteners.

S *.SS

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SISS * S SS' S. * * I S **

Claims

CLAIMS1. A panel for use in lining an arched structure with an internal framework, the structure having a floor and a soffit, the soffit having curvature whereby it curves upwardly and inwardly from opposite, first and second sides of the structure to a crown line, the framework being installed within the structure and extending beneath the soffit; the panel having a front surface, an opposite rear, water shedding surface, and at least one attachment portion, the attachment portion being attachable to the framework so as to support the panel in an installed position in which it is inclined downwardly from an upper edge of the panel to a lower edge of the panel, and in which the rear surface faces in an outward direction towards the soffit and the front surface faces in an inward direction away from the soffit characterised in that the panel includes an upper wall and a lower wall, the upper wall extending from the rear surface generally in the outward direction proximate the upper edge of the panel, the lower wall extending from the rear surface generally in the inward direction proximate the lower edge of the panel, the upper and lower walls being configured to shed water from the rear surface of a first said panel to the rear surface of a second said panel when the first and second panels are arranged in the installed position in a partially overlapping configuration and at an angle, one relative to the other, corresponding to the curvature of the soffit; and an elongate recess is formed adjacent the lower wall, and the upper wall of the second panel is configured to extend into the recess of the first panel in the overlapping configuration in the installed position; and the angle is variable within a range, and the upper and tower walls are configured to shed water from the rear surface of the first panel to the rear surface of the second panel when the angle lies anywhere within the range.bus'.
2. A panel according to claim 1, characteriSed in that the rear surface diverges from the front I,,..surface downwardly in the installed position towards the lower edge of the panel.

S..... 35
3. A panel according to claim I or claim 2, characterised in that respective longitudinal edges of S the respective front surfaces of the first and second panels are configured to abut one another in the ° installed position in the overlapping configuration when the angle lies anywhere within the range.S *5
4. A panel according to claim 3, characterised in that the front surface of the second panel overlaps the recess of the first panel in the overlapping configuration in the installed position.
5. A panel according to any preceding claim, charactensed in that the angle is variable by at least 15 degrees within the range.
6. A panel according to any of claims 1 -5, charactensed in that the rear surface is divided into a plurality of channels, the channels extending downwardly towards the lower edge of the panel in the installed position. I0
7. A panel according to any of claims I -5, charactensed in that the panel includes a body portion made from rigid foamed plastics material.
8. A panel according to claim 7. characterised in that the rear surface is divided into a plurality of channels, the channels extending downwardly towards the lower edge of the panel in the installed position, and the channels are formed in the body portion.
9. A panel according to claim 6 or claim 8, characterised in that the channels decrease in depth towards the lower edge of the panel.
10. A panel according to any preceding claim, charactensed in that the upper and lower walls are configured to shed water from the rear surface of the first panel to the rear surface of the second panel in the installed position when the rear surfaces of the first and second panels are both inclined at not more than 2 degrees from horizontal
11. A panel according to any of claims I -10, characterised in that the front surface of the panel comprises a rigid board attached to the body portion.
12. A panel according to any of claims 1 -10, characterised in that the front surface of the panel comprises a thin layer or coating attached to the body portion.
13. A panel according to any of claims 1 -10, charactensed in that the front surface of the panel comprises a metal skin attached to the body portion. S...* 35
14. A panel according to any preceding claim, charactensed in that the front surface is substantially flat. * * S * **15. A lining installed within an arched structure with an internal framework, * the structure having a floor and a soffit, * S 0 0 * .S SOthe soffit having curvature whereby it curves upwardly and inwardly from opposite, first and second sides of the structure to a crown line, the framework being installed within the structure and extending beneath the soffit; the lining comprising two parallel adjacent arrays of panels, and at least one flexible, waterproof shield; each array comprising at least first and second panels according to claim 6, claim 8 or claim 9 arranged in the overlapping configuration in the installed position; the shield including a central attachment portion and two outwardly extending lateral portions, the central attachment portion of the shield being arranged between the framework and the soffit, each lateral portion having a front surface which faces in an inward direction away from the soffit and an opposite, rear surface which faces in an outward direction towards the soffit; the front surface of each lateral portion having a plurality of water guiding structures; the shield being arranged between the two arrays of panels such that each respective lateral portion partially overlaps the respective rear surfaces of the respective adjacent array of panels.16. A lining according to claim 15, charactensed in that the front surface of each lateral portion has a plurality of water guiding structures which extend in parallel with a longitudinal axis of the shield.17. A lining according to claim 15 or claim 16, charactensed in that the front surface of each lateral portion has a plurality of water guiding structures which extend obliquely with respect to a longitudinal axis of the shield.18. A lining according to any of claims 15 -17, characterised in that the central attachment portion of the shield includes a compressible structure which cushions the framework against small movements of the soffit.19. A lining according to any of claims 15 -18, characterised in that the central attachment portion of the shield includes a resilient clip structure. *..*S S...20. A lining according to any of claims 15 -19, charactensed in that the shield is extruded from S....* 35 plastics material. *. *21. A panel substantially as described with reference to the accompanying drawings. * * 0SS*S*..S 40 ** . * **