"Two trains in the same platform" at Rennes

[whole diary]

[stuving]

I wonder why SNCF^▸ (Societe Nationale des Chemins de fer Francais - French National Railways) have been making such a big fuss about their new mid-platform signals at Rennes, permitting "two trains in the same platform" (2TMV). This appears, from limited evidence, to be fully signalled platform sharing. There are also platform markings, of course, and rather complicated ones by the look of it. After Rennes, this will be rolled out across other suitable stations - not just short of capacity, but with long platforms and a suitable mix of train lengths and  movements. They seem to be aiming at two trains that depart in opposite directions, so either one or (more likely) both must be originating.

Apparently at Rennes they could previously manage to share platforms only seven times a day "for safety reasons", presumably because of the extra times and staff needed to supervise the permissive working. This kind of signalling is described as already in use in Germany and Switzerland, and the Rennes project has cost 12.6 M€.

Only French reports so far; here's a couple of older ones from 20 Minutes and SNCF, and a new picture from Le Parisien.

[Noggin]

Ummm, isn't this what they do many, many times a day at Temple Meads?

[Red Squirrel]

Indeed. Until recently they used St Andrews Crosses rather than signal lights. And the trains don't even necessarily need to be going in opposite directions; I've been stuck on a northbound train on an even-numbered platform (i.e. at the country end) waiting for another northbound train on the odd-numbered end of the same platform to leave to clear our path.

I have noticed that trains on even-numbered platforms seem to stop a long way short of the 'join', sometimes beyond the canopy, which can be irksome!

[grahame]

Indeed. Until recently they used St Andrews Crosses rather than signal lights. And the trains don't even necessarily need to be going in opposite directions; I've been stuck on a northbound train on an even-numbered platform (i.e. at the country end) waiting for another northbound train on the odd-numbered end of the same platform to leave to clear our path.

I have noticed that trains on even-numbered platforms seem to stop a long way short of the 'join', sometimes beyond the canopy, which can be irksome!

Stacking is not new ... it was even done routinely at platform 2 in Swindon from December 2013, with a 2 car 150 parked up on long turnover on the Cheltenham service parked against the buffers while a single carriage 153 buzzed in from Westbury and back out at the extreme end of the platform.  That has now changed, with the Cheltenham trains running to / from London, and the Westbury service of necessity now 2 or 3 carriages.

[GBM]

Joining still done at Plymouth.

[eightonedee]

Also happens (or used to before I retired last year!) on the bay platforms 4-6 at Reading. Sometimes two North Downs trains would be on one platform, so confused passengers would try to get in the nearer/inner one only to be shooed further up the platform to join "the front train". On one occasion in the evening we arrived at one of the platforms behind an SWT^▸ (South West Trains) train that was due to depart shortly (so therefore in front of it from a departure point of view) resulting in loud unhappy comments from its crew.

Back in the 1980s, a late train back home from London would involve a change for Tilehurst, then my home station. On Platform 8 (if I recall the old numbering correctly - the through platform on the relief lines on the central island platforms) there would be a single car "Bubble Car") that would be the stopping train towards Didcot on the west end, and a 3-car unit at the eastern end that would be a "stopper" back towards London. The west facing bay platform 6 (remember that?) was occupied by a Midland region unit that was the something past one unit that stopped everywhere on the way to Birmingham and connected unofficially with the Midnight Riviera for those who ignored "pick-up only" at Reading for an even later train home!

[stuving]

Joining still done at Plymouth.

And lots of other places, both here and in France - which was the point of the question "why are SNCF^▸ (Societe Nationale des Chemins de fer Francais - French National Railways) making such a big fuss?".

The key seems to be in the claim that making this a signalled move saves a lot of time. That does not seem to be the case, or not so marked, her so I guess the rules in France are more restrictive and cautious. If so, that is one reason there would be less reason to do it here, though I'm sure here are those who would advocate it just to reduce the risk.

The other reason given, that it's a cheap alternative to building platforms, applies much more in France. At Rennes the platforms are all 400 m long, and apart from double-length TGVs^▸ (Train a Grande Vitesse) there can't be many trains that long. However, the same logic does apply here, for the short local/regional trains we have.

The final selection criterion is having congestion and  suitable movements: basically two trains leaving in opposite directions. That can't be very common here or in France.

[Sulis John]

Two trains scheduled to depart in opposite directions may well be a frequent occurrence if you have services terminating from opposite directions and not running through. Think Ormskirk and mentally remove the buffer stops, for example.