Couplings

A quick query - was on a steam railway this summer where the loco was coupled to the train of carriages with a fixed coupling off the loco of the instanter type rather than a screw coupling. Is this practice accepted as I have not seen it before?

Thanks
Anthony

 

There's probably nothing illegal about it but I wouldn't think it was good practice. Better than using a 3-link, though, assuming it was instantered up to short link! Certainly wouldn't have been allowed on the big railway. Coupling of passenger trains need to be tight in order to give as smooth a ride as possible. Any slack between the vehicle buffers is going to provide a rough ride for the passengers.
I'm guessing that it was on an industrial loco? A big problem with them is that they frequently have relatively short buffers and, in such cases, they need packing out with hardwood timber so that the screw coupling can be tightened up.

 

Would tend to agree - probably an industrial or shunting loco. Standing instructions are to always use the loco coupling when attaching to a train. So - if the loco has an instanter, then that's the one to use.

 

An offbeat question I sometimes ask people about coupling up is: 'If you are coupling a grey wagon to a green loco which coupling would you use, and why?' Before anybody jumps in, it only applies to BR locos/liveries!

 

All I can think of is "Number 9" et al with a buckeye on the tender??? Not having any instructions on these foreign types - I would be lazy and use the wagons coupling!!!!!

 

The A4's do show which loco crew members play with coaches as well as engines...

 

The answer would be the wagon coupling, grey wagons being unfitted and having either three link or instantaer couplings the draw bar load on the wagon is evened out by having the same strain imposed at both ends of the vehicle.

 

Your correct. The grey wagon, being unfitted would have a three link coupling. The green loco makes it a passenger loco with a screw coupling. The BR General Appendix required the use of the loco coupling in coupling carriages or fitted freight stock to the loco, However, when an engine is attached to a loose couple freight vehicle the wagon coupling should be used. Some black (ie freight locos/shunters) had three link couplings and the loco coupling would then be used.
The General Appendix allowed the attachment of one Instanter fitted vehicle to a passenger train but the screw couplings on the adjacent vehicles had to be used.

Re the use of a buckeye on an A4 as mentioned by someone else, it is perhaps ironic that on the NYMR No.60007 is frequently paired with the LNER teak set and the leading coach of that set (the GNR Saloon) is not fitted with a buckeye coupler so the emergency screw coupling needs to be used.

 

In what way does the load on the drawbar vary depending on which coupling is used? It's still being attached from the same loco to the same wagon drawbar whichever way you do it.

 

I can only think that if three link couplings are used at both ends, the snatch on starting away is equal. If a screw is used on the loco end and a three link at the other all the snatch will be at the three link end.

 

There's been a big discussion about couplings on RMWeb. here's the thread
proper use of three link couplings - UK Prototype Questions - RMweb