If I remember correctly freight trains can be fitted, unfitted or partially fitted. If a train is unfitted am I correct in thinking that the train would use Instanter coupling and if fully fitted would use the screw coupling. I’m not sure about partially fitted but I can’t see it feasible to use Instanter and screw fitted couplings on the same train, either one or the other. Then again, is the Instanter coupling used in the close couple position or not, as the case may be. Any thoughts would be appreciated please.
I believe that fitted freights have a continuous vacuum along the train, partially fitted only have a vacuum along part of the train and unfitted freights have no continuous vacuum brake along the train. This is very oversimplified as to go into all the ins and outs I would be here all evening!
Modern fitted freight have an air pipe so allowing the engine to brake using it’s air brakes. Vacuum braked trains could be partially fitted. The unfitted section would have through pipes to allow the vacuum to travel to other vacuum braked vehicles in the rake. Although, I do have a memory that unfitted wagons have to be placed in a certain position within the rake. But my main question was about the couplings used and which coupling to be used in any given circumstance. Cheers anyway.
Sorry I was talking about the oldern days as I've never been involved in the modern railway. Sorry I have no idea then. Also unfitted wagons would be at the back of the rake.
One slight wrinkle to this was "piped" wagons that had brake pipes but no brakes. As you note wagons with brakes were marshalled by the loco' in a train so those brakes would be used. Piped wagons, though unbraked, could be marshalled in between braked wagons because the through pipes allowed the wagons on the side away from the loco' to still have their brakes connected.
I don’t believe any trains running on the current UK routes in the game are unfitted. That may change with Spirit Of Steam, possibly.
This is why I posed the question. In the scenario on Tees Valley line 0Z53 which is dealing with two rakes of coke wagons, they look as if they are air braked because it is an air pipe that is connected between the wagons, but they are using a Instanter coupling, which I thought was only used on unfitted wagons, but perhaps I am wrong. Perhaps someone can put me right, if that is the case.
Instanter couplings were used on a lot of wagons on fitted freights certainly never only on unfitted wagons. Unfitted freight in the UK finished in the late 80s to early 90s and Vacuum braked freight not long after.