What's involved in increasing line speed?

[sburnley]

It was announced not too long ago that the line speed between Wolverhampton and Shrewsbury was to be increased. From my travels along that line it seems to be mostly straight and smooth and it seemed to me that the train could easily travel faster than it was doing.
So what does it take to raise the line speed - would the track be relaid, or the ballast tamped better, or simply more frequent inspections to ensure that the current track remained safe to travel on at the higher speeds?

 

[Tomnick]

Someone else recently posted a vast list of items that need to be considered before the linespeed can be raised, and a lot of it doesn't involve the permanent way. One significant example is signal spacing (can trains still stop at a signal at Danger after passing the first signal displaying an adverse aspect?).

 

[PinzaC55]

Someone else recently posted a vast list of items that need to be considered before the linespeed can be raised, and a lot of it doesn't involve the permanent way. One significant example is signal spacing (can trains still stop at a signal at Danger after passing the first signal displaying an adverse aspect?).

And signal aspects would often be increased from 3 to 4 aspects.
Plus cant (superelevation of the rails on curves) and if it was Bullhead track it would be changed for CWR (continuously welded rail). Lineside notices such as "WHISTLE" would need to be moved forther from the things they applied to, and level crossing barriers would need to be retimed.

 

[Tomnick]

4-aspect signalling and CWR wouldn't necessarily be needed to allow any linespeed upgrade! For example, taking a relatively low-capacity route with 2-aspect signalling, stop signals say 5 miles apart - there's no need to upgrade the whole lot to 3-aspect signalling with shedloads of additional signals unless a capacity increase was required too. All that would be absolutely necessary would be shifting the distants out to provide the necessary braking distance. Likewise for the p-way - existing jointed track, flatbottom or bullhead, might still be suitable for the increased speed.

 

[Bald Rick]

See last post on this thread...

http://www.railforums.co.uk/showthread.php?t=41315&page=2

And this thread generally

http://www.railforums.co.uk/showthread.php?t=44131


There are more than 80 factors that affect linespeed, and they ll have to be checked.

As for Wolves - Salop, it's nearly ready.

 

[The Planner]

Nothing is being done to the signalling on Wolves - Salop, Its more of a structures and track quality thing. This scheme has dragged on for aaaaaaages.

 

[sburnley]

It is far more potentially complex, and interesting, than I thought. I would never have imagined that resonance effects from trains passing over bridges would be part of the mix, for example.

 

[ACE1888]

Some great information on this Forum, the 'Rail workers' input and knowledge is most helpful for an 'enthusiast' like myself

 

[shinkansen1966]

On the subject of line speed increase, what's happening with Midland Main line general increase from 110mph to 125mph ? By December 2013, supposed to be an 8 minute reduction in London->Sheffield journey and, at last, a sub 2 hr journey time.

 

[swt_passenger]

On the subject of line speed increase, what's happening with Midland Main line general increase from 110mph to 125mph ? By December 2013, supposed to be an 8 minute reduction in London->Sheffield journey and, at last, a sub 2 hr journey time.

Current published dates are:

GRIP 6 (work on site) commences June 2011

Early works commissioning December 2011

Main works commissioning Timetable change December 2012

Late works commissioning Timetable change December 2013

Source: NR enhancement plan update Mar 2011.