GB2317634A

GB2317634A - Levelling railway lines

Info

Publication number: GB2317634A
Application number: GB9620397A
Authority: GB
Inventors: Daniel George Porter
Original assignee: AMEC RAIL Ltd; SOUTH WEST INFRASTRUCTURE MAIN
Current assignee: AMEC RAIL Ltd; SOUTH WEST INFRASTRUCTURE MAIN
Priority date: 1996-09-30
Filing date: 1996-09-30
Publication date: 1998-04-01
Also published as: WO1998014662A1; GB9620397D0; AU4562897A

Abstract

A method of levelling a railway line 8 which comprises a series of parallel sleepers 10 which are laid on a ballast bed 12 and which support rails 14, comprises locating a gap 16 between a sleeper 10 and the ballast bed 12, positioning the sleeper 10 at the desired level, removing some ballast to expose the gap 16, and passing further filling material 24 into the gap 16 from a filling outlet 18 located in the gap 16. The filling means 17 may comprise a hollow steel tube having at one end a connection 20 to a compressed air line A, the outlet nozzle 18 at the other end, and a container 22 containing chippings 24 connected between the ends, so that the chippings are drawn into the pipe by passage of the compressed air.

Description

APPARATUS AND METHOD FOR LEVELLING RAILWAY LINES The invention relates to a method of levelling a railway line.

A railway line may comprise a series of parallel sleepers laid on a bed of ballast and supporting rails. After time, the ballast may settle unevenly leaving a gap between the ballast and one or more sleepers. Any such gap can cause the sleeper and hence the rails to sink when no train is present and/or when a train passes over that portion of the rails. These gaps are undesirable, and are filled.

One known method of filling these gaps uses a Tango" hammer.

An operator uses the Tango" hammer to force additional chippings into the gap between the sleeper and the surface. This method will only work if it is possible to see any such gap.

Additionally, use of a Kangow hammer for long periods of time is restricted, as operators can develop "White finger", where blood supply is cut off from the fingers.

A further known method of filling the gaps uses a vertical hollow spike which is hammered into the ballast adjacent the gap using a Kangon hammer. Chippings are then fed down the hollow spike into the gap. The volume of chippings is related to the perceived size of the gap. This method is also unsatisfactory as use of a Tango" hammer is still required and the operator can not directly see the gap that is being filled. Furthermore, should the hollow spike become blocked by a stone before the gap is filled, it will appear to the operator that the gap has been filled to rejection as no more stone can flow through the hollow spike. This method may not ensure, therefore, that the gap has been filled correctly.

According to the invention, there is provided a method for levelling a railway line comprising a series of parallel sleepers laid on a bed of ballast and supporting rails comprising the steps of locating a gap between a sleeper and the ballast bed; positioning the sleeper at a required level; removing an amount of ballast to expose the gap; locating in the gap an outlet from a filling means; passing a filling material through the outlet into the gap until the gap is filled.

According to the invention, there is further provided filling means for use in levelling a railway line, comprising a generally longitudinal hollow pipe provided with an inlet at one end for connection to a source of fluid under pressure and an outlet nozzle at an end opposite said one end and a material container having an outlet into said pipe intermediate the ends thereof so that material placed in the container is forced out of the nozzle when fluid flows through the pipe, the nozzle and the pipe being formed in one piece.

The following is a more detailed description of an embodiment of the invention by way of example only, reference being made to the accompanying drawings in which: Figure 1 is a cross-sectional schematic view of the layout of a railway track showing a sleeper of the track laid on a ballast bed with gaps between the sleeper and the ballast.

Figure 2 is a schematic side view of a blowing tube for use in filling gaps of the kind shown in Figure 1.

Figure 3 is a similar view to Figure 1 but showing the blowing tube of Figure 2 positioned to fill a gap beneath the sleeper of Figure 1.

Referring first to Figure 1, the railway line 8 comprises a substantially rectangular sleeper 10 laid on a generally horizontal ballast bed 12. Rails 14 are subsequently laid on the sleeper 10 and held in position by rail fastenings 11. After a period of time in service, the ballast forming the ballast bed 12 may settle, due to the pressure of trains travelling on the rails 14, causing gaps 16 to form between the ballast bed 12 and the sleepers 10. These gaps 16 can cause the tracks to move by up co 50 to 75mm, although movement of around 25mm is more usual.

In order to prevent damage to the track and to provide a smoother ride for trains it is necessary to fill the gaps 16 with chippings or similar.

This filling uses the blowing tube of Figure 2 which comprises an elongate rigid pipe 20 provided at one end with an inlet for connection to a compressed air supply (not shown) and, at the end remote from this connection, with an outlet nozzle 18. At a point between the two ends, the pipe 20 is connected to a material container 22 where the container 22 has an outlet into the pipe 20. The container 22 is filled with chippings. The nozzle 18 and the pipe 20 are formed in a single piece - they may be formed from a single member or formed in two parts and fixed together by, for example, welding.

In order to level a sleeper 10, once a gap 16 is located, the sleeper 10 is first positioned at a required level. This can be done using surveying equipment. A portion of the ballast bed 12 is then removed from beside the sleeper 10 to allow the operator to see the size of the gap 16 and to allow the outlet nozzle 18 of the blowing tube to be placed in the gap 16. The container 22 is then filled with chippings 24 and the compressed air flow switched on and controlled by a valve 26. The chippings 24 may be of smaller size than the ballast 12 supporting the sleeper 10.

For example, the chippings may be 6-18mm nominal size stone.

The air will flow in the direction of arrow A through the pipe 20 and through the outlet nozzle 18 into the gap 16. This air flow will draw the chippings 24 from the container 22 and force it through the outlet nozzle 18 into the gap 16. The air used is 689.5kPa (100 psi), however it will be appreciated that any suitable air pressure may be used.

When the gap 16 is filled with material 24 (i.e. no further material 24 can be pushed into the gap 16) the operator can gradually withdraw the outlet nozzle 18 from the gap 16 whilst also back filling the remainder of the gap 16. This continues until the gap rejects any further chippings 24. The air is then shut off to prevent the transfer of further chippings 24.

During the filling procedure, the operator can see the remainder of the unfilled gap 16 between the ballast bed 12 and the underneath surface of the sleeper 10. Should the blowing tube stop issuing chippings 24 from the outlet nozzle 18, for example if the outlet nozzle 18 becomes blocked by a stone, the operator will be able to see that the outlet nozzle is blocked and that the gap 16 is not yet filled to rejection. Visibility is good as the outlet nozzle 18 can be positioned in a generally horizontal configuration, allowing the operator a better view of the work area. Additionally, there is no longer a requirement to "hammer in" the hollow spike, thus reducing the time taken to complete the maintenance work.

The accuracy required in positioning the nozzle 18 is not important provided the nozzle 18 is in the gap. Furthermore, the outlet nozzle 18 of the blowing tube can be positioned directly in the gap 16 as after the required ballast has been removed from the ballast bed 12 the operator can see the gap 16.

As no Kango' hammering is required in the method described above with reference to the drawings a single operator can use the equipment for extended periods of time without the onset of white finger.

It will be appreciated that any suitable fluid may be used in place of compressed air. Additionally, the outlet nozzle 18 configuration need not be as described and any suitable outlet nozzle configuration may be used, for example the nozzle may be bent. Furthermore, multiple nozzles 18 may be provided.

The apparatus may be provided with a handle for ease of use.

Generally, the blowing tube is formed from steel, however, it will be appreciated that any suitable rigid material may be used.

It will be further appreciated that the filling material need not be gravel and that any suitable filling material could be used.

Claims

1. A method for levelling a railway line comprising a series of parallel sleepers laid on a bed of ballast and supporting rails comprising the steps of locating a gap between a sleeper and the ballast bed; positioning the sleeper at a required level; removing an amount of ballast to expose the gap; locating in the gap an outlet from a filling means; passing a filling material through the outlet into the gap until the gap is filled.

2. A method according to claim 1, wherein the passing step comprises the steps of placing chippings in a container forming part of said filling means, passing said chippings from said container to said gap via a pipe and said outlet.

3. A method according to claim 1 or 2, wherein said chippings are passed into said gap by air pressure.

4. A method according to claim 3, wherein the air pressure is 689.5 kPa (lOOpsi).

5. A method according to any preceding claim, wherein the gravel is approximately 6 to 18 mm nominal size.

6. A method according to any preceding claim, wherein the positioning step comprises the step of raising the sleeper.

7. Filling means for use in levelling a railway line comprising a generally longitudinally hollow pipe provided with an inlet at one end for connection to a source of fluid under pressure and an outlet nozzle at an end opposite said one end and a material container having an outlet into said pipe intermediate the ends thereof so that material placed in the container is forced out of the outlet nozzle when fluid flows through the pipe, the nozzle and the pipe being forced in one piece.

8. Filling means according to claim 7, in which the fluid is compressed air.

9. Filling means according to claim 8, in which the air pressure is 689.5kPa (lOOpsi).

10. Filling means according to any preceding claim, in which the material is chippings.

11. Filling means according to claim 10, in which the chippings are 6 to 18 mm nominal size.

12. Filling means according to any preceding claim, in which the pipe is formed from a rigid material.

13. Filling means according to claim 12, in which the rigid material is steel.

14. Filling means according to any preceding claim, in which the filling means is provided with a handle.

15. Filling means according to any preceding claim, in which the nozzle is welded to the pipe.

16. Filling means according to any preceding claim, in which the angle between the nozzle and the pipe is less than 1800.

17. Filling means as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

18. A method of levelling railway lines as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings