Chiltern railway - potential for higher speeds?

[adamedwards]

I've just finished this rather nice cab ride video of Birmingham to London Marylebone:

. The video makes the speed limits very clear and it's most impressive how much of the line from Banbury to Northolt is 100mph (aside from High Wycombe). It's also interesting that the line north of Banbury is only 90mph maximum despite being the Cross Country route to Reading. This leads me to speculate as to how much of this could be upgraded to 110mph or 125mph. ( I know with HS2 it would probably not be justified, but this is the mad speculation bit of the Forum!)

So what could be upgraded above 100mph and how much faster might that make the route for journeys, assuming a magic money tree and suitable rolling stock is available?

 

[Bletchleyite]

Is there much point? HS2 will be the fast route within not too long, and the WCML IC services the budget option. Chiltern will return to being a local railway primarily serving local custom, basically comparable to the WCML LNR services.

 

[cle]

Banbury to Leamington could definitely do with uplift.

Other than that, I would see journey time improvements coming through wires, which I think would make a good difference on this route - with both topography and stopping patterns at play.

As to whether it's worth increasing north of High Wycombe, once slow service thins out - I don't know what 125mph electric from there to Banbury would yield, and whom for (given Oxford isn't going to benefit much)

 

[Bletchleyite]

Other than that, I would see journey time improvements coming through wires, which I think would make a good difference on this route - with both topography and stopping patterns at play.

Completely agree. The gain would be via acceleration vs. the sluggish DMU service. Post HS2 services will be much slower to provide local services.

 

[hexagon789]

It's also interesting that the line north of Banbury is only 90mph maximum despite being the Cross Country route to Reading.

It isn't btw it's 100mph as well. There is 90/HST95 from 97.75mi to Leamington Sth Jcn. (Approx 8.75mi), there is also 90/HST100 from Hatton Nth Jcn. to just south of Solihull (approx 12.25mi).

These (and other) HST limits were in place long before the Chiltern Line south of Banbury into Marylebone was upgraded from 75mph.

 

[The Planner]

Knightcote embankment at Fenny Compton has always been a problem child, hence the 75mph. Again, remember 90 to 100 is 4 seconds a mile, so 15 miles needed to get the minute you might not be able to take advantage of.

 

[NoRoute]

Post HS2 services will be much slower to provide local services.

Seems unlikely, all of those existing passengers along the route using it to get to London or Birmingham, they won't be taking HS2 and won't want to see journey times increase.

 

[adamedwards]

Agreed, which is why there is a need to keep the 100 mph services at least as they are. My original post was promptedby the thought that many of the sections of 100mph route would appear to be good for higher speeds than that and so what potential there could be for speeding up say Banbury or Bicester to London (journeys which will never be via HS2). I'm also very aware that raising low speed limits is even better than raising the high speed sections. Is there any potential for getting better speeds out of the section south of Neasden Junction? I assume this is slower due to clearances? Even higher point speeds at Moor St and Marylebone ought to be worth looking at. Time for another Project Evergreen?

 

[The Planner]

Agreed, which is why there is a need to keep the 100 mph services at least as they are. My original post was promptedby the thought that many of the sections of 100mph route would appear to be good for higher speeds than that and so what potential there could be for speeding up say Banbury or Bicester to London (journeys which will never be via HS2). I'm also very aware that raising low speed limits is even better than raising the high speed sections. Is there any potential for getting better speeds out of the section south of Neasden Junction? I assume this is slower due to clearances? Even higher point speeds at Moor St and Marylebone ought to be worth looking at. Time for another Project Evergreen?

I would ignore Moor St anyway as it gets expanded as part of Midlands Rail Hub, a lot, if not all, will go through to Snow Hill and terminate to create the capacity. Point work at Marylebone is 25mph anyway, you aren't going to hammer into a platform end 200 odd metres in front of you much quicker. Its 50mph for the last 3 miles, you would need 70mph to get a minute out of it.