All 3 configurations were used and one would hope that they would all be available for PFR. It would be great if the 104 was layered into all the routes that used them, which is many. Someone correct me if I'm wrong, but, ironically, I believe that some ended their lives on the Goblin Line. Apart from a possible US route, this is about the only thing I'm looking forward to in TSW.
Towards the end of their working life, when a small fleet was allocated to Old Oak Common to cover the Gospel Oak to Barking service they ran as 2 car power twins, with the centre cars removed. However in their heyday the usual formation was three cars.
3 car yes. Not sure they ever ran as 4 car formation within the same unit as that would kill the power to weight ratio.
There were 4 car formations formed with a DMCL at each end with a trailer brake and a TSL but they wouldn't have been used on the PFR route, I think they were mainly used on the eastern region. The Buxton ones were 3 car sets.
