At that time, the Edinburgh/Glasgow sleeper was the only train requiring a banker. However, on Friday's it ran in two portions, neither of which normally required a banker, so getting banked on a Friday was anomalous and I guessing the evening you travelled it was either above the normally permitted load or your train engine was not in the best of health.
The class 47 was what we, the spotters on Garrington's Bridge by the banker mess-room, used to refer to as the 'Worcester banker'. This was a single shift turn from Worcester that supplemented the two class 37's, arriving at Bromsgrove about 2000. It would seem that Worcester would pull whatever arrived on a teatime working from Paddington and send it to Bromsgrove for a night out (about the best night out one could get in Bromsgrove, let me tell you!). Normally this a slightly rarer than the normal range of Western Region class 47's, although for a special treat we would get a class 50, so those spotters still young enough to have a parentally enforced curfew would contrive to ensure the curfew stretched to just after the scheduled arrival of the Worcester banker as there was no knowing what we could be getting. Less popular would be when a class 37 turned up, although at shift end the Bromsgrove crew had a beauty contest amongst the three class 37's on site and the weakest one got sent back to South Wales. Rumours abounded that Peaks and Westerns had appeared at various times as the Worcester banker, although I never saw such a thing.
Despatch of a banked train was by way of the plunger you observed and RA lights. On arrival at Bromsgrove, the train driver pressed a plunger notifying 'ready to start' to Gloucester Box. Meanwhile, the bankers would be following the train, signalled permissively, stopping by the nearest to the train rear of one of a sequence of trackside plungers. One of the crew would press the plunger (allegedly it was unwise to do this while still hanging onto the loco as it resulted in a mild electric shock) to signify bankers ready to start. The bankers then had 15 seconds to get into position ... gently does it with the sleeper ever since a crew were a bit rough one night and knocked that Sir Somebody out of bed. If they were going immediately, as the signal cleared this also cleared a RA repeater on a gantry visible to the banker crew.
Getting out of the Bromsgrove and onto the incline was tricker than it might first seem, particularly with a loose-coupled freight. The worst problem was from the loop where the train snaked right, then left and then the gentle right curve through the station, so the front part of the train might be on the incline while the rear part was being pushed through the reverse curves ... it is unwise to give a loose-coupled short wheelbase train too much of a squeeze or everything might, and indeed sometimes did, end up in a pile between St Godwald's and Finstall Road Bridges. And two class 37's pack quite a punch.
Of course, by the later 1970's and into the 1980's, the end was in sight for regular banking on the Lickey Incline and officialdom largely overlooked what was happening at Bromsgrove. With long gaps in banked trains during the day, I remember an incident where one of the drivers disappeared on an errand. Unfortunately, control decided to send a class 25 hauled special freight and routed it onto the main rather than loop, judging there was enough time to get it inside at Barnt Green before the following express. Anyway, the drivers assistant, a relatively new traction trainee, got the bankers into position, yet wisely decided not to go without the missing driver on board, so they just sat there. Eventually the express came into view and instead of a lovely 80mph run at the bank, was checked into the loop, through the speed restricted loop and carefully out of the loop and onto the incline before applying power. Do not imagine they had an easy ascent. Rumours abounded that the missing driver, who arrived soon after all the excitement, had a 'no tea' summons to explain himself, although he was phlegmatic man who doubtless took it with equanimity. Rumours also abounded concerning when the bankers suffered an earth fault exiting, or not as the case may be, the turn back loop at Blackwell one night. Blocking main lines with two derailed class 37's does tend to draw officialdom's attention, particularly where there is potential for contradictory accounts concerning what actually happened.
Ah I see what you mean. There was a general cutting back of sleeper services back then for a few different reasons.
