Post by Deleted on Jan 13, 2006 18:32:56 GMT
dunois said:
I was more thinking about North Greenwich than La Courneuve ligne 7 for a deep level equivalent as for sure build two island plateforms with three tracks would be very expensive.I see your point, a side and island arrangement would be cheaper than two islands, particularly for deep level tube construction. North Greenwich is however of a cut and cover construction rather than deep level tube construction. If all trains were to be reversed in sidings, then given LULs tipping out policy, then the island would be more suitable on the arrival side. If reversing were to be split between sidings and the centre platform track, then it would be better to have the island on the departure side.
If reversing were to be done on all three platform tracks, then I don't think it really matters where the side and island platform are located, although the side platform is usually located on the inbound side. However I don't think a deep level three platform reverse in platform terminus would provide any capacity increase over a two platform reverse in platform terminus. This is because of the increased track seperations increasing the size of the crossover, thus increasing crossover transition times. There would also be passenger flow problems.
