Another 'Alternate history' scenario

[mike57]

On the face of it a fairly simple one.

Assuming the 'London Extension' of the GCR had survived in some form or other. By survived I mean track bed intact, and major bits of infrastructure, e.g. bridges, tunnels etc still in place and subject to basic maintenance so can be brought back into use. Doesn't have to have a service of any sort.

At a guess its about 65 miles to where in interesects with HS2 near Brackley.

So the question, assuming the island platforms were removed what sort of line speeds would be acheivable if the track was relaid to get the best possible speed within the old railway boundary.

Its part of an ongoing discussion off this forum about the value of preserving unused transport routes, and the costs of future re-instatement v build from scratch

So the question is what speeds would be acheivable over the section northwards from roughly Brackley to allow a London - Leicester and Nottingham service, with possible onward extension northwards. The assumption is also non tilting, and no major reconstruction of tunnels or bridges.

I always understood the alignment was pretty straight with only gentle curves for the most part.

I am not considering if we would **want** to do it if the route had survived in some form, just what could be acheived if it had survived.

 

[The Planner]

On the face of it a fairly simple one.

Assuming the 'London Extension' of the GCR had survived in some form or other. By survived I mean track bed intact, and major bits of infrastructure, e.g. bridges, tunnels etc still in place and subject to basic maintenance so can be brought back into use. Doesn't have to have a service of any sort.

At a guess its about 65 miles to where in interesects with HS2 near Brackley.

So the question, assuming the island platforms were removed what sort of line speeds would be acheivable if the track was relaid to get the best possible speed within the old railway boundary.

Its part of an ongoing discussion off this forum about the value of preserving unused transport routes, and the costs of future re-instatement v build from scratch

So the question is what speeds would be acheivable over the section northwards from roughly Brackley to allow a London - Leicester and Nottingham service, with possible onward extension northwards. The assumption is also non tilting, and no major reconstruction of tunnels or bridges.

I always understood the alignment was pretty straight with only gentle curves for the most part.

I am not considering if we would **want** to do it if the route had survived in some form, just what could be acheived if it had survived.

Its much less than 65 miles where HS2 intersects it, its at Grendon Underwood effectively. I imagine if it was desired to get to 125mph north of there, it could have done.

 

[HSTEd]

Your best bet for saving the GCML is that the 'Paytrain" and 'Basic Railway' concepts appear early.

Which would mean a single track line like the West of England Main Line.

Not sure how practical recovering it into a major line would be.

 

[Helvellyn]

One of the reasons for island platforms was to allow Fast Lines to be built around the stations at some future date when traffic picked up. Not sure if the route was built in a corridor that would have allowed future four-tracking throughout. Assuming, however, that it was and all that land remained in railway ownership then though expensive it would have allowed for a two-track higher speed route to built in that corridor, with curves as shallow as possible.

 

[Gloster]

Which would mean a single track line like the West of England Main Line.

I presume that you mean the Waterloo-Exeter line beyond Salisbury. The West of England Main Line is the one via Newbury, Westbury and Taunton: the only singled bits of this were west of Plymouth.

 

[30907]

I presume that you mean the Waterloo-Exeter line beyond Salisbury. The West of England Main Line is the one via Newbury, Westbury and Taunton: the only singled bits of this were west of Plymouth.

Oddly enough the name seems to have remained attached to the SR route, while the WR, with its piecemeal history, has the Berks and Hants label for its direct route - does the label GWML apply beyond Bristol to Plymouth?

 

[mike57]

Your best bet for saving the GCML is that the 'Paytrain" and 'Basic Railway' concepts appear early.

Which would mean a single track line like the West of England Main Line.

Not sure how practical recovering it into a major line would be.

I wasn't really looking at how it survived, just that the trackbed and major infrastucture are still intact, allowing it to be rebuilt using modern track and signalling, probably a similar situation to Oxford Bletchley, and given the alignment what would be the maximum acheivable speed over the route, staying within the original railway boundary assuming track and signalling were new and suitable for high speeds, if it were to be used as an HS2 spur.

The original discussion centred around the premise that the rules for rail closure had protected the route for a period of time, maybe 50 years, and the impact that might have had on future developments and the costs associated with them generally, not just the London Extension. It was very much a 'what if' discussion.

 

[Indigo Soup]

As far as I understand it, the London Extension was only a 'straight, fast railway' by the standards of the 1890s, with lots of curves that would restrict speeds to essentially the same as the other main lines from the Midlands to London. I'd guess it could be a faster route than the MML, but wouldn't be significantly different from the ECML/WCML - that is to say, a 110/125mph railway.

I believe it was appreciably flatter, but this was mostly for the benefit of freight traffic.