How feasible would upgrading routes be?

[Bartsimho]

Just looking at a map of Line speeds and it's clear that many lines have really low Line speeds (such as Nottingham-Lincoln) but how feasible would it be upgrading these lines to even a speed of 85mph?

Surely it's not the Level Crossings existing as Trent Junction to Derby has 110mph Line speed and LC's?

 

[yoyothehobo]

At lot of it depends on the infrastructure, embankments, ground quality, cant of the line, profile of the curves and similar.

There are projects looking at line speed increases.

However there are other things to look at, if you have a bunch of stations close together and you have little time where you would be running at those speeds, then its not worth it as by the time you have accelerated its time to slow down again so you need fast accelerating rolling stock as well in these cases.

If you need to change a curve cant profile or radius to allow your speeds it can rapidly become a very very costly affair.

 

[stuu]

Also... Signal spacing and sighting, condition of the track, dynamic envelope - faster trains can move about more, and a great many other factors. Bald Rick who contributes here and knows what he's talking about said there are over 100 factors to take into consideration. He may have listed them somewhere

 

[Dr Hoo]

Just looking at a map of Line speeds and it's clear that many lines have really low Line speeds (such as Nottingham-Lincoln) but how feasible would it be upgrading these lines to even a speed of 85mph?

Surely it's not the Level Crossings existing as Trent Junction to Derby has 110mph Line speed and LC's?

The crossings between Trent and Derby have full barriers. Many level crossings (including farm and footpath crossings) between Nottingham and Newark with far lower levels of safety integrity.

Quite apart from any physical characteristics the route carries services from as far away as Crewe, Leicester and Grimsby. These have to pass through various busy nodes and fit the extremely limited slots across the East Coast Main Line on the flat. It is far from obvious that any speed increase could be effectively exploited without significant timetable rewrites.

 

[Bartsimho]

The crossings between Trent and Derby have full barriers. Many level crossings (including farm and footpath crossings) between Nottingham and Newark with far lower levels of safety integrity.

Quite apart from any physical characteristics the route carries services from as far away as Crewe, Leicester and Grimsby. These have to pass through various busy nodes and fit the extremely limited slots across the East Coast Main Line on the flat. It is far from obvious that any speed increase could be effectively exploited without significant timetable rewrites.

But timetables are rewritten very often so could be changed over the time of upgrading the line to accommodate the increased speed.

 

[Bald Rick]

There’s over 80 factors to consider Before raising linespeeds.

The first is the difference between feasibility (can something be done) and viability (is it worth it).

There are a number of linespeed improvement projects that have realised next to no benefit as the timetable could not be made to work. Eg Perth to Inverness, Marches line, and more besides.

 

[Pinza-C55]

Does the traffic on Nottingham - Lincoln warrant the expenditure for 85 mph ? For one thing the signal spacings may need to be altered.

 

[Brubulus]

The crossings between Trent and Derby have full barriers. Many level crossings (including farm and footpath crossings) between Nottingham and Newark with far lower levels of safety integrity.

Quite apart from any physical characteristics the route carries services from as far away as Crewe, Leicester and Grimsby. These have to pass through various busy nodes and fit the extremely limited slots across the East Coast Main Line on the flat. It is far from obvious that any speed increase could be effectively exploited without significant timetable rewrites.

There would be a huge timetabling benefit to increasing speeds between Lincoln and Newark as it would allow trains to pass while crossing the ECML, allowing 2tph along that line from Lincoln with the 2 paths an hour across the ECML

 

[The Planner]

But timetables are rewritten very often so could be changed over the time of upgrading the line to accommodate the increased speed.

Define very often, they are published every 6 months, but in the majority of cases just rolled over. You don't change a timetable until you know the work is done and if they don't tally up you don't see the benefit for a while.

 

[zwk500]

But timetables are rewritten very often so could be changed over the time of upgrading the line to accommodate the increased speed.

They're tweaked every so often but not actually rewritten wholesale more than once every few years. Upgrading the linespeed where a train is at one end of it's journey can largely be accommodated quite easily, but if it's in the middle of the journey then often any speed can't be realised as the slots at the junctions don't move.

There would be a huge timetabling benefit to increasing speeds between Lincoln and Newark as it would allow trains to pass while crossing the ECML, allowing 2tph along that line from Lincoln with the 2 paths an hour across the ECML

A flyover may well be better value for money overall though by eliminating the crossing altogether.

 

[MattRat]

Well first you should check if anything can take advantage of higher speeds, and if so, what's that vehicles max speed. I think you'll find upgrading to 90 or 100 makes much more sense that 85, and even then, there's still a lot of stock that can only do 75, although a lot of it is older stock that will eventually retire.

 

[HSTEd]

Does the traffic on Nottingham - Lincoln warrant the expenditure for 85 mph ? For one thing the signal spacings may need to be altered.

You might be able to justify it if you were making the UK equivalent of the Akita or Yamagata Shinkansen.

With ETCS and line speed upgrades you might be able to get journey times to Newark (and thus Lincoln) competitive with the ECML (currently 26m plus 57m to Nottingham via HS2), although obviously to use route for trains to points further north you'd need a new Chord at Newark.

Short of that, I doubt you could get the money to do anything.

 

[zwk500]

You might be able to justify it if you were making the UK equivalent of the Akita or Yamagata Shinkansen.

With ETCS and line speed upgrades you might be able to get journey times to Newark (and thus Lincoln) competitive with the ECML (currently 26m plus 57m to Nottingham via HS2), although obviously to use route for trains to points further north you'd need a new Chord at Newark.

Short of that, I doubt you could get the money to do anything.

You could, of course, just not stop as often.

By far the most effective intervention is to remove the lowest speed restrictions, not increase the highest speeds. Stops are the obvious things to start with, requiring a reduction of speed to 0.

 

[HSTEd]

You could, of course, just not stop as often.

By far the most effective intervention is to remove the lowest speed restrictions, not increase the highest speeds. Stops are the obvious things to start with, requiring a reduction of speed to 0.

The 26 minute time from Nottingham to Newark Castle only stops once! By contrast the train with four stops only takes 29 minutes. Even with 7 stops it takes only 33 minutes.

Not much scope for time savings from that in this case! The speeds are simply too low, especially with modern-ish multiple units.

EDIT:

The ruling linespeed is only 60mph, with significant slower sections superimposed on it.

 

[zwk500]

The 26 minute time from Nottingham to Newark Castle only stops once! By contrast the train with four stops only takes 29 minutes. Even with 7 stops it takes only 33 minutes.

Not much scope for time savings from that in this case! The speeds are simply too low, especially with modern-ish multiple units.

EDIT:

The ruling linespeed is only 60mph!

The difficulty is that as you increase the linespeed, the penalty for stopping increases so if you did want to decrease journey times by Linespeed uplift you'd need to start dropping stops anyway.

 

[Bald Rick]

There would be a huge timetabling benefit to increasing speeds between Lincoln and Newark as it would allow trains to pass while crossing the ECML, allowing 2tph along that line from Lincoln with the 2 paths an hour across the ECML

You could timetable it that way now. It just has other constraints to overcome. Exactly as it would if the linespeed was increased. You have to look at the whole thing.