AU636389B2 - Roadway rail - Google Patents

Abstract

A rail for vehicles to travel on is supported from a surface (14) by flanges (17) extending transversely from the top of the rail (11). The rail has a groove (16) for the road wheels. The rail is recessed into the road surface in a relatively shallow recess (12). The rail has a low profile since the loading on the rail is taken on the surface and is not carried down as usual to a substrate for the surface.

Description

PT/GB 9 0 0 132 1 08 August .zr

ROADWAY

FILD OF HE INVE NION The present invention concerns a roadway h-avin a rail installed in it. Such roadways are used in particular for joint use by road vehicles and railsayj vehicles especially light railway vehicles.

BACKGROUND OF HEE PRESENT INVENTION The rails for a railway are I beams suppprted by transverse sleepers on a bed of ballast on a fprepared base. WheYe a road crosses a railway, the strface of the road is level with the tops of the rails and the space between the rails is then built up. These rails have a high profile in that the width of the rail is very much less than the depth. For street railways or tramways a similar high profile rail is used. Thus tramways used a so-called phoenix rail which is generally an I beam but with a groove for flanges of the vehicle wheels formed in the upper flange. To install such a rail in a road, it is necessary to excavate the road surface to a depth of at least 50 centimetres to provide for a sleeper or bed of concrete under the rail which itself would be 18 centimetres depth. Such a deep excavation entails re-routing underground services such as water and electricity mains and destroys the integrity of the road construction. Ways of reducing the depth of excavation have been developed in Dresden in the late wherein the rail was cast in concrete panels about centimetres deep (but this involved shortish lengths of rail which had to be welded together) and in Budapest by Dr. Zahummensky in which rails are inserted in steellined channels in concrete panels with the rails being 7 centimetres deep and the panels 18 centimetres deep.

A snag with such panel systems is that the panels have a tendency to settle or rock, in the -Dresden system this is resisted by the rigidity of the phoenix-type track.

in International Patent Publication WO 84/00 3 91 there is described a phoenix-like rail consisting of an Ibeam with a small foot and a large head. This is sa-d to lead to a reduction in the number of sleepers and ,ij OiT ingd Ptent Office SUBSTITUTE SHEET I pCT interntIonalI Application

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PCT/GB 9 0/ 013 0 8 iugust 19S 08 08 other bed structures because flanges formins the head take substantially or"essentially all the loading onto the roadway which is of crushed stone structure a possibly bound by a surface coating of bitumen. It is Ssaid that the depth of excavation needed to install the rail is reduced but as illustrated it shows than the excavation is more than twice the depth of the rail. It would seem moreover that the rail has to be rather deep since crushed stone would tend to settle unless the stiffness of the rail resisted suchJ settling. U.S. Patent 3089650 shows a rail with flanges towards the top but these flanges are to provide a suitable area moment in a weighing device.

This rail would not be suitable for use in a roadway since the groove is large being intended to receive the entire wheel width and not merely a wheel flange and such a large groove would tend to'trap road vehicle wheels and be dangerous.

SUMMARY OF THE PRESENT INVENTION The present invention provides a roadway having a recess in which is installed a rail, which rail has an upper surface for supporting vehicle wheels, a groove in that surface for receiving wheel flanges of those wheels, a bar portion providing that surface and that groove, and a pair of flanges extending integrally from the bar portion to spread the rail's wheel loading over part of the roadway' s surface characterised in that the rail has a depth substantially less than its width and in that the recess, whilst shallow has a depth such that the rail can settle into the recess so that the rail is effectively suspended from the flanges.

Modern roads in.cities where light railways are more likely to share a road with road traffic are built to high standards capable of carrying 40 tonne vehicles with 11 tonne wheel loadings. These roads are expensive to construct and the present invention minimises the amount of excavation needed to install rails. The flanges serve the functions of spreading vertical loading, gripping S the roadway to resist cross-loading, and to minimise damage lOt ciil a nt ftio SUBSTITUTS SHEE a7 j gional Application FCT/G8 9 0 /013 2 ,0 P August 1991 08 08 91 to the roadway due to water seeping down the sides of the bar portion. The flanges can have ridges to bite into the roadway and/or a sealant can be used ;o provide a water seal and to absorb sideways loading.

Where sideways loading is expected to be very large, sections of phoenix track can be used.

BRIEF DECRIPTION OF THE DRAWINGS Figure 1 is a section of a rail fitted in a roadway, Figure 2 is a perspective view of a pair of rails fitted in a roadway, and Figure 5.is a perspective view show~n, a rail intersection. DESCRIPTION OF AN EXEMPLARY EMBODIMENT Figure 1 illustrates on a large scale a rail 11 in a shallow recess 1 in a roadway 14. The recess can be, for example 4 centimetres deep and 10 centimetres wide.

The rail has a central bar portion 15 which is generally a regular trapezium in section but with a groove 16 for a vehicle wheel flange in the wider surface which in use 20 is the uppermost surface of the rail. Extending integrally sideways from the bar portion, there is a flange 17 on each side of the rail. The recess is preferably cut out by suitable cutters such as disc or other cutters cutting the sides of the recess and such as a plane or other cutters removing the material remaining between the cut sides of the recess. The recess is then partially filled with a suitable material 18 so that when a rail is inserted in the recess the rail can be settled into the material 18 so that the vertical loading is effectively taken by the rail being suspended from the flanges. The rail can be of steel, iron or another material rolled, extruded or, otherwise fabricated into the squat T-shape illustrated.

The rail can be secured in place by mechanical or other means such as an adhesive bond which preferably has a degree of resilience as is provided by Corkelast. It is possible to provide ribs or a shallow groove in the underside of each flange to improve the sealing and the resistance of the rail to sideways movement. Rails can be welded or otherwise joined end-to-end to form a jnited Kingdom Patent Office SUBSTITUTE SHEtT POT Inten!ntional Application *l l^ c I* I I -i PCT/G8 9 0 0 1 3 2 03 Auguai iy- 0 8 08 31 continuous track and can be laid under tension to avoid thermal expansion problems. As shown in Figure 2, a pair of rails will normally be used and a pair of recesses can be cut simultaneously using ganged cutters to ensure correct spacing. Cross ties not illustrated can be provided at intervals to form gauge defining devices and these can be recessed below the roadway surface.

To avoid crossing road traffic and in particu.ar two-wheeled v hicles such as pedal and motor cycles being inconvenienced by the smooth metallic bumps formed by the rails, the space between the rails 11 is built up to the top ci the rails by a thin layer of tarmac 20 or other road facing material. It would be possible to recess the flanges slightly in the road surface so that they are substantially flush with the roadway and then merely fill the seam alongside the flanges with tarmac or the like. It would also be possible to have the flanges slightly down from the top of the rails with tarmac or other material on top of the flanges to minimise O0 the amount of metal exposed.

Figure 3 illustrates a junction piece which would be cast or otherwise formed and comprises two rails 21 and 22 crossing at an angle with the grooves in the two rails extending across the central intersection 23. Where more complicated arrangements are involved such as junctions, special provisions might be made 'fUnited ingdom Patent Office SUBSTITUTE SHEET CT In ional Application SUBSTITUTE

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WO 91/02843 PCT/GB90/01325 such as the provision of sections of conventional phoenix tracks but a suitable adaptation of Figure 3 is possible.

The present invention is mainly for use where road vehicles and track vehicles share road space. Such situations arise where there are tramways or light urban railways. The invention can be used even when such tramways or urban light railways run on segregated tracks and even for mainline railways. ihere segregated tracks or mainline railways are involved the roadway in which the rails are laid can be made of heavy concrete or stone slabs or panels or even on a continuous concrete bed laid in situ; with such concrete roadways there would have to be expansion joints but the recesses can be formed during manufacture or laying wet concrete.

For example the recesses can be formed by a slip-form paviour or other machine. The low profile rail according to the present invention offers advantages due to the reduction in rail height over traditional railway track especially when a track is being adapted for electrification or gauge conversion since it woud-, not be necessary to lower an existing track bed possibly exposing wall foundations in existing tunnels.

The rails can be used for signalling or electric -power supply if the rails are insulated. However it is probably not possible to supply suffidient power to drive a vehicle in this way but only to use the rails as a return path and then it would be desirable to bond the rails to a low resistance earth cable at intervals to avoid earth leakage currents interfering with other services.

The cross-section of the rajis depends on the use.

The groove is shaped to suit the ittended traffic and can,'for example not only engage those wheels supporting a vehicle but also steering wheels which engage the groove and transmit steering information to the supporting wheels.

The central bar portion would be deep enough to provide an adequate groove and typically would be about 7 centimetres deep with 4 centimetres recessed in the roadway, and would be typically 10 centimetres wide with the WO 91/02843 WO 9102843PCr/G B90/0 1325 6flanges extending further out hy sufficient distance bearing in mind the substrate load-bearing capacity to suspend the rails fro= the roadway so the vertical and. horizontal loading on the rails is taken on the upper surf~ace of the roadway without appreciable settlement unlike the previous systems wharein the vertical loading was taken to the bottom of the rails.

,Even when the flanges are of'fset or recessed down the bar portion and. the fl1anges as we'l as the bar portion ar- recessed in the roadway, the vertical loading is taken near to tL- top surface of the roadway. it is thought that having the flanges recessed into the road~way will only be practical when the recesses are preformed during roadway laying or when the rails can.

be laid. during roadway construction w..ith the final.

surfacing burying th fl ang~es without raising the intended level of' the roadway.

Claims (8)

1. A roadway having a recess in which is installed a, rail, which rail has an upper surface for supporting vehicle wheels, a groove in that surface for receivins Sw.heel flanges of those wheels, a bar portion providing that surface and that groove, and a pair of flanges extending integrally from the bar port i on to spread Sthe rail's wheel loading over part'of the roadway's surface characterised in that the rail has a depth substantially less than its width and in that the recess, whilst shallow, has a depth such that the rail can settle into the recess so that the rail is effectively suspended from the flanges.

2. A roadway according to claim 1 wherein the rail is secured in place by mechanical or other means.

3. A roadway according to claim 1 or claim 2 wherein the flanges seal onto the road's surface.

4. A roadway according to claim 1, claim 2, or claim 3 wherein the rail is formed from lengths welded together.

5. A roadway according to any one of claims 1 to 4 having two rails cross-ng at an angle with a junction piece for the said a o rails' comprising an integrally cast or otherwise ormed member consisting of intersecting bar portions crossing at the said angle with grooves in the bar portions extending across the central intersection and in line with the grooves in the rails.

6. A roadway according to claim 5 wherein the junction piece is of phoenix design.

7. A roadway according to any one of claims 1 to 6 wherein each rail is one of a pair of parallel rails.

8. A roadway a~cording to any one of claims 1 to 7 wherein the bar portion is roughly 7 ,entimetres deep with 4 centimetres recessed into the roadway and roughly 10 centimetres wide with the flanges extending further out by sufficient distance bearing in mind the load bearing capacity of the roadway's surface to suspend the rail from the roadway's surface without appreciable settlement. p/ 3IJicn TU T 1 PCT/GB 90/03~5 0 3 AUqUS1 1~991 08 91 8 roadway according to claim -7 hereinthroda betw.-een- each Lair of rails is built atD to the level o-f the top of the rails. 1; T