Capacity has the easiest fix on the planet: minimum unit lengths.
Varies between 75-80m on each one. The gaps between the signals between Oxford Road and Picc are only 452 and 413m to the mid platform signal and its 194m from the mid platforms to the end. Deansgate to Oxford Road is effectively one signal section. Short of having ETCS block markers equivalent to the signals and effectively planning on single yellows, I can't see what the solution is.
The only way to make any meaningful difference short of metroisation (i.e. unified Stock + ATO) would be to go to minimum block lengths (c.50m) but then you get to the problem of trains potentially being stuck half-in and half-out of a platform.
I am sure the signals don't permit trains to enter the B platforms unless the train infront has passed the main platform starter signal (except in certain circumstances). The mid platforms just save a small bit of time because of overlaps.
See https://www.railforums.co.uk/thread...row-express-type-shuttle.246415/#post-6156336
As I think I posted in that thread at some point, I've seen it happen, stampede and all. Maybe only if the first train has stopped far enough forward to clear the overlap?
Yes, probably if it’s short enough. 6x185 (which was what I used yesterday on the 10:58 to Victoria) is too long.
I've been looking, but I can't really find any hard minimum limit on block lengths in ETCS.
Theoretically I suspect the limit is a single digit number of metres, as it will just be about can the axle counter get a clear reading. but 50m is a rough estimate for practical purposes as otherwise you've just go an insane number of axle counter sections (and the accompanying data setup for the routes, chance of failure, etc).
Minimum blocks we see on Thameslink is 60M.
Platform 13 has a blind corner - not had a cab view but I'm pretty sure the stairs block the view of a train in the departure end until a following train is very close. And as I've already pointed out, it's undesirable from a crowd control point of view to have a second train stopping in the platform and passengers start moving past the narrow part to get to that end.
As far as I'm aware nobody has seriously proposed quadrupling between Piccadilly and Oxford Road. The capacity bottlenecks are the two stations.
Looking at satellite view, it does seem like some demolition would be needed for quad tracking, however a second island platform is probably more realistic. Some grade separated junctions at either end would also help
Two extra through platforms at Piccadilly, much where your red lines are, were officially proposed a few years ago, as a later part of the same overall project as the Ordsall Chord, and got as far as a public inquiry, but Chris Grayling when transport minister refused to fund them. There would also have been realignments and lengthening of the four through platforms at Oxford Road and abolition of the terminal platform. But edwin_m's point in your quote was that the line would have remained just two tracks at the narrowest point between Oxford Road and Piccadilly.
One an hour in each direction.
The dwell times are the bottleneck, so alternating use was indeed intended. This required adequate signalling overlaps beyond the platforms so a train could be arriving in one while the previous train was signalled out of the other one.
On the routes out to Reading and Shenfield the EL shares track with freight.