TEN years on today - how time flies!

Much of the funding for this work came from money available because of the cancellation of a r-o-a-d scheme with many people oiling the wheels including certain TravelWatch SouthWest directors.  Although we are currently bemoaning (to a greater or lesser extent) the demise of "Restore Your Railway" I also see some early signs that we might - just might - be seeing signs of an intent to make significant improvements. Fingers crossed, touching wood, not walking under ladders and with a "Plan B" in case the "improvements" are less or different than work for us, but looking forward, nervously, to see what happens and perhaps to helping promote and inform community support.

 

Looking back at Swindon <-> Kemble and working out what redoubling might mean for Chippenham <-> Trowbridge

As it stands ... line capacity 3 single journeys per hour
With intermediate signal if very well planned - say 4.5 journeys per hour
With loop in the middle if well planned - say 8 journeys per hour
With dynamic loops between pinch points - say 12 journeys per hour
Redoubled throughout - say 18 journeys per hour

New double track station - Thanet Parkway - £34 million
(( New single track station - Portway Park and Ride - £6 million ))
Cost of redoubling (Swindon to Kemble, £45 million in 2014) - £60 million

Ongoing extra maintenance costs - £??

 
I've never understood how singling was other than a very short-term economy measure, allowing a section of track that needed replacing to be abandoned instead or perhaps to keep the track away from a slipping bit of embankment. In the longer term the remaining single track gets twice the usage so will broadly wear out twice as quickly, there are points/switches with far more moving parts than plain track to maintain at each end of the single line section, and the signalling needs to be more complicated with more to go wrong, to cater for those points and allow for trains going in both directions on one track.

Perhaps the biggest saving is ironically at stations, with fewer platforms and associated lighting etc to look after and maintain (as with track, each will be used twice as much as on a single line but I'm guessing deterioration is caused more by the weather than footfall), and nowadays with the increasing emphasis on access for all a sensibly positioned platform on one side of the single track could avoid the expense of a footbridge and accompanying lifts.

 
The wartime connection between the two lines was double track. The signal box contrlling it was switched out most of the time.

 

Isn't that in effect what happened, but only as part of the "simplification"? One of the two GWR tracks became the Weymouth Single, and the Pen Mill Single uses the other track at the north and then moves across to take the place of one of the SR tracks into Junction. Much the same could have been done with double tracks, but at the time that was not seen as worthwhile.

NLS does also have the 1:10,000 map "Surveyed / Revised: Pre-1930 to 1961 Published: 1962". The revisions declared as after 1930 are boundaries and major roads to 1961 and major changes in 1957. I'd guess that would include railway changes - but only major ones.  The same thing probably applies to the other smaller-scale maps there, such as the 1:25,000 Provisional Edition; Revised: 1901 to 1957; Published: 1958. What post-1928 revisions are included is not clear, but the two lines are still shown side by side without connection. On the map it says, less than helpfully, "other partial systematic revision 1938-57 has been incorporated".

 

The 1928 25" OS Map at the NLS shows a double track from Pen Mill southwards to Weymouth, but the GWR Clifton Maybank Branch was only single track.  There was also a double track SR line from Yeovil Town to Yeovil Junction, which ran parallel to the GWR line from Pen Mill for a while but did not connect.  The GWR line from pen Mill to Town was also shown as single track. 

The 1938 6" OS shows the same.

Unfortunately these are the most recent maps on the NLS website. 

All that would have been necessary to provide a double track connection would have been a crossover from the GWR double track to the parallel SR double track somewhere along the route.  It seems entirely likely that such a crossover would have been added during WW2, but I can find no evidence to prove it. 

 

Somewhere a dynamic loop between Honiton and Pinhoe to enable half hourly Exeter/ Axminster services.

Crediton to Coleford Jn; currently two separate single lines for Okehampton and North Devon.

Both these desirable schemes are outlined planned by Network Rail but await Govt. decision and funding.

 

Was Yeovil Junction to Yeovil Pen Mill EVER double all the way?

The railway geography of the area is complex and my understanding is that there was a line from Yeovil Junction to Yeovil Town, and then a reversal to get you to Pen Mill.  Connection added 1943.

 
Thinking of part singling lines... Kemble - Swindon, versus the practice of dynamic loops as in the Scottish Borders Railway and probably the Highland Main Line... there's presumably optimum places to position the loops, and then, places that it would *not* be a good idea to put them.

There must be computational models that can suggest the optimised pattern if a line does *have* to have single track sections - a pattern for the maximum capacity for traffic and another for how well a particular schema copes with disruption.

Back to Kemble and if anything *had* to be singled it that Kemble to Swindon would have been the section best retained as double track as offering more resilience overall than, say, singling Kemble to Sapperton? Thankfully now in the past.

Off topic, but Ribblehead is weird. An entirely double track main line, singled across the viaduct, but it's not uncommon for your train to wait for the short section to clear. Perhaps it's just the way the traffic on the line is organised, with the delay offering resilience to the timetable overall. The signal might be the one at the exit to the loop there rather than the one that briefly halted that lot...

Mark

 

Pinhoe > Yeovil Junction > Yeovil Pen Mill > Castle Cary so that it provides a proper diversionary route, whenever there is an Exeter<>Castle Cary block of any kind, without disrupting GWR Weymouth & SWR Waterloo schedules.

 
Kemble was the station local to me for a few years at the start of the 'eighties and I wrote a couple of letters to BR, one about the need to redouble the line - the second being that they needed to do something for people ineligible for a railcard. (It was increasingly uncommon, at the station, to see people who looked to be between the ages of 26 and 60)

(Fast forward a few years and I thankfully had an annual season ticket holder's additional nominated railcard - can't recall its name - meaning that running a business involving not much income and a certain amount of travel could be done car-free, which was a blessing for everyone...)

Mark

 

And I would be voting for two tracks from Chippenham to Trowbridge, and four platform tracks through Westbury.

 

I wouldn’t want the job of setting priorities nationally, but it would certainly be good to see Narroways Jct to Clifton Down redoubled. And ‘Four Tracks Now’ from Bristol Temple Meads to Parson Street.

 
We had a very good thread during the time the works were being planned and carried out. 

http://www.firstgreatwestern.info/coffeeshop/index.php?topic=3266.0

 
9 years ago today - from the BBC


Which other previously singled routes should be redoubled next?