"andypurk" wrote

So he did, I wasn't paying attention. However the flat junction with a 3:1
split isn't so bad, especially as the route will be under ATO through the
junction and presumably there will be the opportunity to have a bit of
recovery time at Elephant and Castle or London Bridge for the Up trains
(due to having more than one platform available) allowing train to arrive
at the junction at the correct time. I would imagine that the junction at
St. Pancras may be more of an operational problem with only a single
platform to accommodate the merging trains from two routes.

AIUI in normal working there will only be one up platform for Thameslink
trains at each of London Bridge and Elephant & Castle, although there will
be access to other platforms for exceptional working. Clearly a high
standard of operating will be needed at Blackfriars Junction where 18 tph up
London Bridge trains have to cross 6 tph down Elephant trains. The timetable
will no doubt be based on parallel working, i.e. up and down London Bridge
trains will pass at Blackfriars Junction, as will up and dowm Elephant
trains. However, the plans show three Thameslink tracks between Blackfriars
station and junction, so in perturbed working a down Elephant train will be
able to clear Blackfriars station and wait short of the junction for a path
across the junction. Meanwhile a following down London Bridge train will be
able to overtake and move on to the spur down to Metropolitan Junction.

Peter