"MIG" wrote

One frequent cause of delays is not so much the busyness of the
two-track section, but the fact that trains heading for platform B at
Waterloo East, and occasional Thameslink trains, get trapped in the
bottleneck by trains coming from Platform C at Waterloo East.

The fact that this happens so often means that the section can't really
be at capacity in terms of moving trains that could fit through, but
any solution I can think of, like pairing by direction through Waterloo
East, would cause horrible crossing movements between there and Charing
Cross instead. Maybe any flyover should be near Jubilee Gardens
instead?

This sounds as though the signallers at London Bridge are, perhaps, not
quite as clever as they might be. There are two crossovers at Metropolitan
Junction, a signal block apart, so if a train for platform B will conflict
with a down train at the first one it can cross behind it at the second. Of
course, if everything is running precisely to time, the WTT is based on
parallel working, so that a train for platform B passes one from platform A
at Metropolitan Junction, while trains to/from platforms D/C also pass at
Met Jn. If necessary, there's another crossover at Belvedere Road, between
Waterloo East and Hungerford Bridge, and for an up train to be replatformed
at Waterloo East is one of the few cases anywhere that replatforming won't
inconvenience passengers.

There is, however, a very strong case for some extra track at Metropolitan
Junction to eliminate the single lead faced by Thameslink trains, if TL2xxx
isn't going to happen very soon. The present layout means that a northbound
Thameslink train can't run through Metropolitan Junction parallel to
anything, not even an ecs between Cannon Street and Blackfriars Reversing
Siding.

Peter