Potential speed of an alignment (reopenings)

[biggus]

I have seen a Network Rail study into reopening an old alignment in which they model the fastest theoretical time that a passenger train could traverse the route. They appear to provide an upper ceiling based only on the inherent limitations imposed by curves and gradients and the capabilities of the trainset (they compare hypothetical speed profiles for a Pendolino with another EMU).

Would the necessary tools for producing such an estimate be available to mere mortals, or is this expensive proprietary technology? Any direction would be much appreciated.

 

[The Planner]

I would presume they have used Railsys by RMCom to do the modelling for this, that is about £10,500 for a licence on the internal NR purchasing system. What study have you seen ?

 

[biggus]

What study have you seen ?

That was the 2008 NR study into Uckfield-Lewes reopening... Appendix 6

http://www.eastsussex.gov.uk/NR/rdo...C-E9F16849E956/0/lewes_uckfield_appendix6.pdf

And I see now that it was Voyagers vs Turbostars not Pendolinos vs Electrostars... it doesn't say whether tilt-mode was evaluated and there is not much discussion of the timing exercise in the published version of the report.

I have been fantasising about reopening of another Sussex line, the Cuckoo line from somewhere near Polegate to Redgate Mill Junction near Eridge.

It is a steep and bendy line, as the curve and profile gradients here confirm: http://www.crjennings.com/Railway Structures Southern/cuckoo line/cuckoo line index.html

The most persuasive case for such a reinstatement would be if it could provide a really good fast service between Eastbourne and London to supplement the currently rather indirect (1h36m) mainline route via Lewes. I am aware of several of the major obstacles to reinstatement of the line (Mayfield Bypass, questionable conformity to modern standards etc). but we don'thave to even worry about those issues if the shiny objective of a fast London service for Eastbourne via the reinstated route would be impossible because of either:

1. No chance of capacity and decent speeds on the existing (currently rather slow, 58 mins) route up to London from Eridge

2. No chance of getting trains up from Eastbourne to Redgate Mill at a decent lick without building a largely new, straightened alignment.

Yes, Hailsham, Heathfield and Mayfield amongst others deserve to be on the rail network again, but relinking small towns is not as sexy politically as putting Eastbourne a whole lot closer to London.

I have walked part of the route and was impressed by the amount of infrastructure that remains in place in terms of bridges and culverts, many of which were built to accommodate double track that was never laid. The line runs through the kind of landscape where forging an all-new alignment would be all but impossible in view of today's political and environmental constraints.

(A six lane motorway would just happen, of course, but not a railway.)

 

[mr_jrt]

I'm in agreement the link should be restored to remove the Eastbourne traffic from the BML and east coastway, not to mention improving their access to London.

That said, it would seem somewhat silly to rebuild an old bendy but level line designed for steam trains when you could just cut a new bumpy but straight line suitable for modern electric traction. The only reason you would have is to minimise environmental aspects, but given it's so far gone it'd essentially be all new build anyway!

The medium-term, best you could probably hope for would be the get the link from Uckfield to Lewes restored on the old alignment, then Eastbourne services could run via Uckfield.