Why is the rear loco treated as 'dead' and does not provide any power, whereas in a back to back formation both locos are providing power? Is it possible to get the rear loco to provide power, or is this just the way it is? I understand that this is fairly realistic, just interested in the details really, as I like messing around with formations and seeing what is possible. Talking about UK, Class 20/31/37/40/45/47s etc...
The locomotives rely on MU jumpers, mostly in the above case Blue Star 27 Way jumpers, with a few exceptions these are not fitted to coaching stock and as such the MU signals cannot physically be transmitted through coaching stock or wagons and as such the locomotives on the other side of the stock cannot be controlled from the lead loco. Any such formations would typically require 2 sets of crew to achieve
Thanks. It was your comments from that classic old thread that explained to me about how to setup all the brakes etc on all those locos. So for the UK, is it just the newer versions of the 66 that they added the banking comm feature to, that can top and tail and both contribute power?
For the Class 66 using the RHTT formations, these are MU through wired for top and tailing. One part the game has semi accurate top and tailing.
Yeah, they did that well. I don't think on the older versions without the banking comm there is any way to get the rear 66 to contribute.
There were also strict instructions pertaining to locos on the tail end, notably that the vacuum exhausters had to be shut down. The only way or time the loco would be powered up was if required for banking purposes and there would be a separate crew on board. Also generally there were no radio comms, crews relied on horn signals to communicate the need for assistance and when to shut off power.
Very interesting. Thanks. I assume the lead loco would still have had responsibility for the rear loco brakes, even though it was manned and providing power assistance?
There was really no need for BR to develop DPU operation, because they didn't run trains that size. Where needed they would push with a helper, and for that the same old system used with steam sufficed.
The only exceptions I can think of apart from the RHTT sets were the Top and Tail Class 27s on the Glasgow Queen Street - Edinburgh Waverley services prior to the introduction of the Class 47/7 + Mk3 + DBSO sets. They used Mk2 stock that had been fitted with wiring for the blue star MU control. I believe the stock used on the Top and Tail Class 37 services on the Wherry Lines was also wired to allow both locos to provide power.
I throw another into the mix, DRS used T&T 37's prior to (and when they were not available) the introduction of the DBSO's on the Cumbrian Coast. Most notable during the 6 months after the 2009 floods where they operated T&T over the mile between Workington and the hastily built Workington North. The rail bridge was the only remaining standing connection between the two halves of the town.
Just remembered another example, T&T Class 31s with 2 Mk2s Bedford - Bletchley 1999 due to non-availability of 1st Gen DMUs due to frequent failures. This is getting a bit like what did the Romans ever do for us...!
