You sound as though you need to do a lot of reading up but here are some basic things.
The production power cars ran from 43002 to 43198 and you needed one each end of a set of trailers which were couple using an alliance centre coupler, power supplied by a 415V cable normally from the rear powercar and controlled by a 27 way jumper cable joining them all together. The power cars were originally designated DMB because the rear of the first series of power cars were equipped with a guards office and a luggage area.
The trailer cars were built as TF Trailer First, TS Trailer Second then a variety of catering vehicles such as TRUK etc. With the first trains in service on the Western Region it was decided that the rear of a 2250hp power car was not the best place for the guard so arrangements were made to build TGS Trailer Guard vehicles which had a guards area at the end of the train coupling to the power car. The TGS fleet allowed so reordering of vehicles into sets, traditionally Western Region HSTs which were designated class 253 were formed with 7 trailers, and the Eastern Region sets were generally 8 trailers between the powercars.
That is enough to get you started, suffice to say that a number of MK3A loco hauled Mk3s were subsequently converted to MK3 HST trailer spec, including some of the Cross Country vehicles as well as some former Grand Central Trailers.
Enjoy you knowledge journey
yeah where the 43s are concerned theres alot of history and reading up, what it is im making a video as tribute and including as much documentary information as possible, all old rail adverts with the class 43 I can find, tv show appearences like top of the pops, blue peter and songs of praise, as many of the old rail transport films I can find for clips and a fair few rare clips that are hard to find. at the end I thought of including the whole this is how many are left, this is where they are and this is their future (to the point of naming each powercar by its original numbers, which was a fair bit of reading in itself xD) so far I have found all that information for the powercars but considering gwr and angel trains comments im not sure if the list is 100% as of now.
18 scrapped
1 waiting disposal and scrap
5 being gutted for parts
3 awaiting repairs
1 damaged
5 exhibition status (decommissioned)
37 in storage (future pending)
2 ceased operations
126 in service (63 trains)
(as of march)
angel trains have 30 odd powercars and have said that storing them is becoming expensive and they are worried about their future as there is not a demand for them
GWR have 35 powercars that are going to be taken off service under GWR in december
crosscountry want to phase out their class 43 stock, I think that was 15 odd powercars
scotrail have taken on loads of class 43s and theres been no comments on scotrail retiring them but its clear that people are not happy in scottland with getting a 60 year old train unit
2035 is something to do with the carriages (need to look into that more)
thats what I have compiled so far, the carriage scrap list is bloody huge though XD I did find one but its long and I dont know how far back it dates and need to try and find the conversion list aswell as some were apparently converted and taken away from the 43s (from what one source said)
I also looked into the 91 43 tag team and that was an interesting bit of information
