Finally, I’ve worked out where Platform 0 at Redhill is going to go. Of course, the answer was buried on RMWeb, and a thread on Rebuilding London Bridge (station.) So, the answer is that platform 0 is going to be parallel to platform 1 on the right of the photo below, next to the clump of trees (that have mysteriously disappeared.)
RMWeb gave this interesting overview of the problems at Redhill, and the signalling issues…..
I suspect the problems with using Platform 1 at Redhill stem not from its length (which definitely is long enough for 12 car Electrostar) but rather its position and some oddities built into (or left out) of the mid 1980s re-signalling scheme.
The problem with its position stems that for Down trains to use it they must cross over (and indeed run along) the Up line either end of Redhill station. Use of platform 1 in the morning for Up trains obviously is easier as it doesn’t interfere with the Down line.
The signalling issue comes from the fact that trains from Tonbridge, Gatwick or Reigate MUST reverse in platforms 1 or 2. There is no signalling to allow a normal passenger move to enter platform 3 from the south which reduces flexibility in dealing with service problems. Additionally for a 12 car train to fit in platform 1, the mid platform signal under the canopy (T491 for regular travellers) needs to show a proceed, however when this is combined with the platform exit signal (T493) being at Red, trains frequently get ‘tripped’ by the TPWS installation for T491 causing the rear of the train to come to a halt over the London end pointwork. I can’t remember the specifics of why it happens off-hand but IIRC when it was fully investigated the conclusion was the issue was due to the design of the interlocking. Normally this is never a problem as most trains that depart southwards from platform 1 are short and the majority have reversed there so get both T491 and T493 showing a proceed together.
Interestingly back in BR days when they were drawing up the specification for the Brighton line resignalling, there was a serious proposal to completely rebuild Redhill with two island platforms (like Haywards Heath) and ditch the through roads. While improving the flexibility and possibilities for passenger services it was rejected on the grounds of its impact on freight handling ability (Holmthorpe sand works was still in full production at the time) plus the likely reduction in speed it would produce for trains diverted away from the quarry lines during engineering works / failures. The other big factor is that BR had renewed the very complex, expensive and bespoke trackwork at the south end of the station only a couple of years before (early 80s that is) and to junk it all after barely a couple of years wear was considered wasteful. Thus the signalling and trackwork you see today at Redhill is pretty much IDENTICAL to that in use back in the 1930s (although at the last-minute a new crossover was added to give direct access to the post office dock from the Down line without the need to perform a shunt maneuver and a couple of the sidings were rationalised).
Platform 0, while providing more platform space will do NOTHING to address the shortcomings of the 1980s signalling system which simply perpetuated the 30s layout and was not designed with todays service in mind (particularly the Gatwick – Reading service which people want to increase to 3tph). What Redhill desperately needs is a remodeling of the layout, particularly at the south end along the lines of NRs proposals I posted earlier, which provide for extensive parallel moves and the ability to easily have two Up or two Down services to be handled (with both calling at Redhill), without awkward conflicting moves currently necessary or needing to fit around trains that reverse there.
And these useful diagrams of present and future trackwork…
Tomorrow, it’s back to Allan’s pictures…..