GB2367050A

GB2367050A - Beam lifter

Info

Publication number: GB2367050A
Application number: GB0016322A
Authority: GB
Inventors: John David Iliffe; William Henry Summers; John Brian Scruby
Original assignee: John Mowlem & Co PLC
Current assignee: John Mowlem & Co PLC
Priority date: 2000-07-03
Filing date: 2000-07-03
Publication date: 2002-03-27
Anticipated expiration: 2020-07-03
Also published as: GB0016322D0; GB2367050B

Abstract

An apparatus is provided for conveying and erecting a support beam (3) inside a railway tunnel. The apparatus comprises a railway wagon (1) on which an extendable platform (2) is mounted. The extendable platform (2) is moveable to a position laterally displaced from the railway wagon (1). A vertically extendable, load lifting tower (4) is mounted on the railway wagon (2) and is moveable onto the extendable platform (2). A rotatable turntable (5) on top of the tower 4 enables a load (3) supported thereon to be rotated with respect to the railway wagon (1).

Description

BEAM LIFTER

This invention relates to a method and apparatus for strengthening the roof of tunnels. Specifically it relates to strengthening the roofs of"cut and cover"type tunnels for railways.

The best way to illustrate the problems which the present invention seeks to overcome is by reference to the particular example of the Circle and District lines of the London Underground railway network.

"Cut and cover"type tunnels are extensively used for the Circle and District lines of the London Underground railway system. Typically, when"cut and cover type tunnels need reinforcement the easiest and most cost effective method to repair the tunnels is to remove the roof and rebuild it from scratch. However some sections of the London Underground tunnels which need reinforcement have buildings erected directly on top of them. This means that removing the roof of the tunnel in these areas is not practical or cost effective and that reinforcement has to be carried out from entirely within the tunnels themselves.

These"cut and cover"tunnels are formed by brick piers supporting cast iron girders which span the tunnel and support a brick barrel vaulted roof. To reinforce such tunnels new concrete walls are provided between the brick piers and"aerofoil"steel beams are supported on the new concrete walls and lie beneath the barrel vaults. Any spaces between the aerofoil beams and the barrel vaults are backfilled with grout. The steel beams must be conveyed down the tunnel to the required location and lifted and secured in position. The steel beams required typically weigh more than 5 Tonnes. There is therefore a need for a machine which can move, lift, slide and position the beams precisely prior to them being secured.

The difficulties of installing the beams from within the tunnel are compounded in the case of operational underground railway tunnels by the fact it is strongly

desirable to keep trains running through the tunnels during the day. Closure of the railway system for any extended period of time results in a loss of revenue and severe disruption. Therefore, as far as possible, the beam installation apparatus must be able to be conveyed to and from the site and must perform installation and then be removed during the so called"engineering hours"each day when the trains are not running.

According to the present invention an apparatus for conveying and erecting a support beam inside a railway tunnel, comprises: a railway wagon; an extendible platform moveable to a position laterally displaced from the railway wagon; a vertically extendible, load lifting tower mounted on the railway wagon and capable of transverse movement with respect to the railway wagon and onto the extendible platform; and a rotatable turntable to enable a load supported on the tower to be rotated with respect to the railway wagon.

Preferably the extendible platform takes the form of a pair of propped cantilever beams on which the tower is slidable.

It is difficult for the railway wagon to be stopped with sufficient precision to be in the correct position for beam installation. Therefore it is preferable for the apparatus to be able to move the beam in a direction parallel to the railway tracks. Preferably the tower is moveable on a traverser sub-frame, mounted on the cantilever beams, in a direction parallel with the railway tracks.

Another preferred feature of the apparatus is that it is adjustable to suit variations in the cant and gradient of the railway track. In a preferred embodiment this is achieved with jacks, placed underneath the cantilever beams and traverser frame, which are adjustable to maintain the tower vertical.

Preferably the apparatus for conveying and erecting a support beam inside a railway tunnel comprises two lifting towers mounted on a single railway wagon.

Preferably the turntable is mounted on the top of the tower. In this case the turntable is preferably adjustable for pitch and roll by small rams positioned underneath the turntable. This is advantageous as a beam can then be oriented in a variety of attitudes during installation. For example this allows one end of a beam to be installed on the top of a concrete wall before raising the other end of the beam into position.

In places the"cut and cover"tunnels of the London Underground accommodate two parallel railway tracks and they frequently include bends. The tracks can also be on a gradient and can have a camber. These features create a number of variable parameters all of which can be accommodated by the lifting apparatus of the present invention. The extendible platform allows the lifting tower to be centrally positioned in the tunnel regardless of the width of the tunnel. Small changes in the position of the tower on the extendible platform can also be implemented to compensate for changes in the relative position of the centre of the tunnel and the wagon on bends. A central position is ideal prior to lifting and rotating the beam, allowing the beam to be supported close to its centre of gravity at all times. It is also important for the aerofoil beams to be level during lifting and rotating as they are only supported at one central point. The jacks placed underneath the cantilever beams and traverser sub-frame can raise or lower corners of the frame to compensate for the combination of gradient and cant and so maintain the tower in a vertical position. The combination of jacks allows the frame on which the tower rests to be effectively pivoted about one corner.

The present invention provides a lifting apparatus which is effective and reliable in a wide variety of conditions and which can manoeuver a beam or other load in

a wide variety of positions. The lifting apparatus is compact and can deliver a beam through a railway tunnel, install a beam and clear the tunnel in a short time.

A particular embodiment of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is an end on view of the beam lifter and beam mounted on a railway wagon with the sideways movable portion in a transit position; Figure 2 is the end on view of Figure 1 of the beam lifter and beam mounted on a railway wagon on a cambered track with the sideways movable portion in an operational position; Figure 3 is a side view of two beam lifters and two beams mounted on a single railway wagon; Figure 4 (a)- (d) are schematic diagrams of a cross section of a tunnel showing the orientation of an aerofoil beam at various stages in the installation procedure; and Figure 5 shows a side view the jack arches of walls of a tunnel.

Figure 1 shows the apparatus in a position for transit. Two lifting towers 4 (only one can be seen in Figure 1) and two pairs of cantilevered beams 2 (only one can be seen in Figure 1) are mounted on a railway wagon 1.

On top of the lifting tower there is a rotatable turntable 5 on which an aerofoil beam 3 is placed. The position of the centre of mass of the aerofoil beam is slightly offset from the centre of the turntable. The beam is in an aerofoil shape in order to fit into the brick barrel vaults in the cut and cover railway tunnels of the London Underground shown in Figure 5.

Figure 2 shows the apparatus of Figure 1 with the lifting tower in an operational position. The pair of cantilever beams 2 are folded out so that they extend laterally from the railway wagon. This folding out action is effected by cantilever beam actuators 9 formed by hydraulic rams. When the railway track is canted, as shown

in Figure 2, in order to ensure vertical lifting of the aerofoil beams the tower must be on a level set of cantilever beams. The cantilever beams are levelled about a pivot point 7-by the action of levelling jacks 6. The cantilever beams are supported by a steel propping frame 8 with adjustable legs, which is secured in place once the cantilever beams 2 are level. The propping frame also folds out from the side of the railway wagon. The cantilever beams are sized so that the footing of the propping frame usually falls between the running rail of the adjacent track and the centre current rail. If this is not the case the footing of the propping frame can be placed on prop support bridges (not shown), spanning across the adjacent track and resting on the running rails.

A traverser sub-frame 15 is mounted on top of the cantilever beams. The traverser sub-frame is able to slide on the cantilever beams in a direction perpendicular to the long axis of the wagon, powered by a hydraulic drive motor.

The tower is mounted on top of the traverser sub-frame and moves with the traverser sub-frame on the cantilever beams.

The tower can move independently on the traverser sub-frame 15 in a direction parallel to the long axis of the wagonlong travel. Long travel is essential to provide positional adjustment after the wagon has stopped, and to allow two lifting apparatuses on the same wagon to be aligned with different jack arches at the same time.

Figure 3 shows a side view of a railway wagon 1 with two beam lifting towers mounted on it. The rail track shown is on a gradient. One tower A is shown in the transit position and the other tower B is shown in an operating position. The propping frame 8, traverser frame 15, turntable 5 and aerofoil beam 3 can all be clearly seen in B. The cantilever beams 2 and traverser frame 15 are levelled both with respect to lateral cant and longitudinal gradient of the track by jacks 6. Movement of the tower on the traverser frame is actuated by hydraulic ram 16. Figure 3 also shows support stillages 10 and 11 mounted on the

railway wagon. These stillages support the load of the aerofoil beams during transit. The aerofoil beams 3 are anchored on the stillages by anchoring 12. Only after the cantilever beams have been folded out into position is the turntable 5 raised to contact, and bear the load of, the aerofoil beam 3. Once the cantilever beams are level the lifting tower 4 is slid on the cantilever beams to the centre line of the tunnel, as shown in Figure 2.

The aerofoil beam is then rotated on the turntable so as to be parallel with the jack arches. This is a rotation of approximately 90 . The lifting tower is then vertically extended to lift the aerofoil beam approximately 1m to be level with the jack arches 20. The beam 3 in the rotated and raised position is shown by the dotted outline in Figure 2 and Figure 5.

The lifting tower is a mechanically guided telescopic frame. The lifting action is provided by two hydraulic rams 14, powered by a self contained diesel driven hydraulic power pack, which is also mounted on the wagon (not shown).

The controls for the lift rams 14 are separate, duplicate and operated in parallel.

The turntable 5 is adjustable for pitch and roll, for reasons which will be explained later, by four small stroke rams 13 in the top of the tower. To achieve the pitch and roll articulation and to ensure an even spread of the load the four lift jacks are hosed to produce a"false three point suspension". One pair is connected hydraulically to allow the oil to flow between them so that they freely take up the angle of roll of the other two. There are just three control levers to control all four jacks, and they cannot work against one another.

The aerofoil beams can thus be moved in all three spatial dimensions and can be rotated and tilted to a particular orientation in space. This flexibility is needed during the installation procedure.

Figure 4 shows a cross section of a railway tunnel and the orientation of an aerofoil beam 3 at several stages

during the installation process. The walls of cut and cover type tunnels in the London Underground system consist of a series of brick arches side by side, as shown in Figure 5. These arches are filled to a certain level with concrete or similar to form piers 21. The piers 21 on one side of the tunnel are formed lower than on the other. At an occasion prior to the installation of an aerofoil beam, a stub end extension 16, together with bearing stool and plate, is placed on the pier, as shown in Figure 4a. The aerofoil beam is subsequently raised by the lifting apparatus until it is aligned with the stub end. The beam and the stub end are then connected to form a complete beam 17, as shown in Figure 4b. The complete beam 17 is then moved back to the centre of the tunnel on rollers 19. In this position the centre of mass of the beam 17 is directly above the centre of the turntable. By tilting the beam using the adjusting jacks 13 beneath the turntable 5, the opposite end of the beam to the stub end is inserted into the higher recess, as shown in Figure 4c. When correctly positioned transversely, the beam is raised to the soffit of the barrel vault. The stub end bearing stool 18 is then positioned under the stub end and the beam is secured.

Finally the recesses are filled with grout. However the grouting can be done after the lifting towers have been packed up and moved away.

The lifting towers are packed up by simply reversing the steps of the lifting operation. The tower 4 and traverser sub-frame 15 are retracted and slid back onto the railway wagon 1 on the cantilever beams 2, the propping frame 8 is then folded up followed by the cantilever beams 2.

The apparatus described above is able to install supporting aerofoil beams into the barrel vaults of a tunnel from a railway wagon quickly and reliably. Most of the individual pieces of equipment that function in the apparatus during the installation procedure have duplicate backups in order that the machine is fail safe. Furthermore

all of the steps in the installation procedure are reversible. This ensures that it is always possible to clear the tunnel before the end of engineering hours.

Claims

1. An apparatus for conveying and erecting a support beam inside a railway tunnel having railway tracks, comprising : a railway wagon; an extendible platform moveable to a position laterally displaced from the railway wagon; a vertically extendible, load lifting tower mounted on the railway wagon and capable of transverse movement with respect to the railway wagon and onto the extendible platform; and, a rotatable turntable to enable a load supported on the tower to be rotated with respect to the railway wagon.

2. An apparatus according to claim 1, wherein the extendible platform is a pair of propped cantilever beams on which the tower is slidable.

3. An apparatus according to claim 2, wherein the tower is moveable on a traverser sub-frame, mounted on the cantilever beams, in a direction parallel with the railway tracks.

4. An apparatus according to claim 3, further comprising jacks placed underneath the cantilever beams and traverser sub-frame which are adjustable to compensate for variations in the cant and gradient of the railway track to maintain the tower vertical.

5. An apparatus according to any one of the preceding claims wherein the turntable is mounted on the top of the tower.

6. An apparatus according to any one of the preceding claims, further comprising small rams positioned

underneath the turntable for adjusting the turntable for pitch and roll.

7. An apparatus according to any one of the preceding claims, further comprising a second extendible platform, lifting tower and turntable mounted on the railway wagon.

8. An apparatus substantially as described herein with reference to the accompanying drawings.