Starting Monday 31st October
(401) 8 700
5W78 03+38 Three Bridges Depot to Three Bridges
1W78 03.46 Three Bridges to Bedford
1V83 06.14 Bedford to Sutton
2V12 08.08 Sutton to St Albans
2O37 09.44 St Albans to Sutton
2O38 11.07 Sutton to Luton
2V67 13.14 Luton to Sutton
2V68 15.08 Sutton to St Albans
2O93 16.44 St Albans to Sutton
2O94 18.11 Sutton to Luton
2V41 20.20 Luton to Sutton
2O48 22.47 Sutton to Bedford
5G48 01+10 Bedford to Bedford CS
As per my diagrams I posted a few days ago.
Did actually see a Thameslink 387 on a Brighton-London Bridge service yesterday though!
Disruption caused by lack of drivers means stock does moves around.
Has Brighton-London Bridge always been run by Thames Link? It seems strange to come under TL and not Southern as I tend to think of TL as being only services that run through the "core"
The service exists because Thameslink trains between Blackfriars and London Bridge have been diverted during building works at the latter.
Prior to Jan 2015, it effectively used to "join up" with the 2tph Bedford-Three Bridges to give a the third and fourth hourly Bedford-Brighton trains, all via London Bridge.
It was split in two to retain an off peak Brighton-London Bridge link (that would otherwise be lost with the diversions), but also keeping 4tph Gatwick-Croydon-Thameslink
Remember that Thameslink, not Southern provides the main non peak service for Three Bridges to Brighton for all stations and has done for many years.
Southern provided the peak service due to Thameslink cutting it's peak service to 2tph rather than the off peak 4tph. This was because most of the peak services could not go via London Bridge so there wasn't the paths via Herne Hill. So the (Southern) 1Bxx exist to keep the link between Brighton and London Bridge.
Note the 1Bxx service is really the old 1Txx type service with the 1Wxx beng more the 2Txx all stations service. The 2Wxx Three Bridges service keeps up the 4tph from MML to Gatwick (and long term it becomes a Gatwick terminator). As Ian states, the existence of the 1Bxx off peak service is to provide the only London Bridge link to the BML off peak.
Come (May) 2018 the 1Bxx will be extended to Cambridge North as a Thameslink service run by 700s. (Peterborough is other service scheduled to start running through the Core in May 2018).
Once the Thameslink programme is finished Southern mainline services will be aimed at Victoria (mostly) with London Bridge services generally provided by Thameslink for BML passengers.