The Anonymous Widower

Will We See More Slab Track On UK Railways?

I ask this question, as I’ve just read this article on Rail Engineer, which is entitled Slab Track Austria: Now A Serious Contender?

 Slab track or ballastless track has a Wikipedia entry.

This is said under Characteristics.

In ballastless tracks, the rails are rigidly fastened to a special type of concrete ties/sleepers that are themselves set in concrete. Ballastless tracks therefore offer a high consistency in track geometry, the adjusting of which is not possible after the concreting of the superstructure. Therefore, ballastless tracks must be concreted within a tolerance of 0.5 millimetres. The elasticity of the ballast in the traditional railway superstructure is replaced by flexibility between either the rails and the concrete ties/sleepers or the ties/sleepers and the concrete or asphalt slab as well inherent elasticity within the conglomerate of the tie/sleeper, whereas the concrete or asphalt slab is usually inelastic.

Applications in the UK recently include.

This picture shows some of the slab track on the Gospel Oak to Barking Line.

I suspect, that slab track was used here mainly because of limited clearance. But low maintenance and long life, must have improved the financial case.

Returning to the Rail Engineer article, it would appear that the engineers behind the slab track, have rethought a lot of the process of building a railway.

Slab Track Austria, which used to be called PORR-STA, seems to offer the following.

  • Factory-build or one-site fabrication.
  • Ease of installation.
  • Accurate alignment
  • Switches and crossing can be fabricated.
  • Transition solutions to ballasted track.
  • Low noise and vibration.
  • Ease of maintenance
  • Sixty year life.

Slab Track Austria would also appear to have worked extensively with Austrian Railways, to get everything as right as possible.

It just shows how much improvement can be squeezed out of some traditional industrial and construction processes.

HS2

TheSlab Track Austria track has also been used extensively on the new Berlin to Munich high speed line, that I wrote about in From Berlin To Munich In Four Hours By Train. This is said about the use of the track on that line, in the Rail Engineer article.

PORR was contracted to design and build three major sections of the railway route. Its patented slab track, STA, was installed over a total length of 320km, in tunnels, on bridges and in open sections. Operations started successfully in December 2015 on the VDE 8.2 section, from Erfurt to Leipzig and Halle. Since December 2017, the sections VDE 8.1.2, from Coburg to Illmenau, and VDE 8.1.3, from Bad Staffelstein to Coburg, have been in operation. Trains have been running on the STA slab track layout at speeds of 300km/h. Prior to commissioning, this slab track was tested at 330 km/h.

So it would appear to be suitable for the 400 kph, that is quoted for HS2, with perhaps a bit of tweaking.

The article also says this about using the track on HS2.

Cost analysis research suggests that the savings made from the reduced maintenance required for STA track will equate to a payback of within 15 to 20 years when compared to ballasted track systems. The opportunity for significant savings, as well as increased network availability due to the reduced maintenance requirement, has to mean that this system is a serious contender for any new railway route, one of which, of course, is HS2.

A dedicated factory producing the slabs would surely increase quality.

But whatever happens, with its numerous, bridges, tunnels and viaducts, I suspect that HS2 will be built using slab track.

In the last quote, a payback time of fifteen to twenty years is suggested, if the track is used on a new railway.

So where else could slab track be used to advantage?

East-West Rail Link

I feel that the East West Rail Link, could be a possibility.

Consider.

  • It will not be initially electrified.
  • It is through terrain that is not very challenging
  • It is fairly close to HS2 and a possible slab track factory.

Building the line with slab track, could help make the East West Rail Link a low-energy and low-noise line for battery or hydrogen trains.

West Anglia Main Line Four-Tracking

Adding two extra tracks to the West Anglia Main Line between Coppermill Junction, which is just South of Tottenham Hale station, and Broxbourne station will be a difficult project.

The line is hemmed in on both sides by housing and slab track might give advantages.

  • Ease to squeeze the tracks in the limited space available.
  • Reduced noise.
  • Speedier construction.

If Crossrail 2 is built, this four-tracking will have to be done.

Calder Valley Line

The Calder Valley Line should be updated to create a quality roue across the Pennines from Preston to Leeds.

Parts of the line would be challenging to improve to say the least, with lots of heritage features around the track.

Using slab track in places, has has been done on the Gospel Oak to Barking Line, might help with the following.

  • The construction works needed.
  • Increasing line speed.
  • Lowering noise.
  • Reduced maintenance.

The Wikipedia entry for the Calder Valley Line has a section called Holme Tunnel Engineering Work. This is said.

Holme Tunnel, which lies between Hebden Bridge and Burnley Manchester Road, was closed for 20 weeks from November 2013 until March 2014. This was to allow for major engineering work to fix the distorted shape of the tunnel, caused by movement of the ground through which it passes. The project was budgeted to cost £16.3million. During the works, buses replaced train services. Trains can now pass through at 45 mph.

I don’t think slab track was used in the work in this tunnel, but do we need 45 mph speed limits on Trans Pennine routes? After reading this article on Rail Engineer, it would appear that 75 mph will be possible in the future.

But this project does show some of the major problems on Trans Pennine routes!

It will be interesting to see what happens on this line.

Other Trans Pennine Routes

The other two Trans Pennine routes, the Huddersfield Line and the Hope Valley Line both have similar characteristics.

  • Twisting routes.
  • Several tunnels.
  • Lots of bridges.

They are also busy with passenger and freight traffic.

When the plans for the updating of these lines is published, I suspect that slab track will feature, especially in some of the tunnels.

Across Chat Moss

George Stephenson had difficulty building the Liverpool to Manchester Railway across Chat Moss in 1829. Wikipedia says this about his solution.

 Chat Moss threatened the completion of the Liverpool and Manchester Railway, until George Stephenson, with advice from East Anglian marshland specialist Robert Stannard, succeeded in constructing a railway line through it in 1829; his solution was to “float” the line on a bed of bound heather and branches topped with tar and covered with rubble stone. The M62 motorway, completed in 1976, also crosses the bog, to the north of Irlam.

I have talked to drivers, who drive Class 319 trains along the now-electrified line across Chat Moss. They told me, that the soft suspension gives an interesting ride.

Under Timings And Line Speeds in the Wikipedia entry for the Liverpool-Manchester Lines, this is said.

The fastest recorded run was from Manchester Exchange to Liverpool Lime St in 30 minutes 46 seconds by a 1936 built Jubilee 5707 with 7 coaches. An 1882-built compound steam locomotive was timed on the same route in 38 minutes 18 seconds. Until 1968 trains from Liverpool to Manchester by all 3 routes were scheduled to take 40 minutes and often took less. The southern route via Warrington is now restricted to 85 mph and the northern route via Earlestown to 90 mph, with 75 mph over Chat Moss.

It would appear that something needs to be done  to get timings between Liverpool and Manchester, back to those of the 1930s.

Would slab track across Chat Moss be part of the solution?

Tunnels

Various tunnel upgrades have shown how using slab track in tunnels is a very helpful technique.

Many tunnels will need to be updated to increase clearance for freight trains and overhead wires and also to solve structural problems caused by anno domini.

I believe we’ll see a lot more slab track in tunnels on the UK rail network.

Noise Reduction

The Rail Engineer article, says this about Slab Track Austria’s slab track.

The elastomeric layer also helps to reduce vibration and structure-borne noise, thus offering protection to supporting structures and reducing the noise created by passing trains – an important feature in built-up areas and tunnels.

So will we see increasing use of slab track in areas, where noise asnd vibration is a problem?

Other Lines

I see the Gospel Oak to Barking Line, as an example use of slab track that will be very much copied.

Slab track has been used successfully in sections, where clearance is limited and noise is a problem.

The use of slab track, might have meant that several bridges didn’t need to be rebuilt.

How many places in the UK have similar needs.

Conclusion

The rethinking of how we build railways by Slab Track Austria, will benefit our rail network and all those who use it.

We’ll be seeing a lot more slab track!

 

 

March 21, 2018 - Posted by | Travel | , , , , , , ,

2 Comments »

  1. Would slab track across Chat Moss be part of the solution?

    I doubt it because the ground “wobbles” as trains pass over. Slab track would crack.

    Comment by Mark Clayton | March 22, 2018 | Reply

    • I suspect the Austrians have a solution for that, like mounting it on something flexible.

      Comment by AnonW | March 22, 2018 | Reply


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