Sprat and Winkle couplings

smyles
Posts: 45
Joined: Fri Jul 25, 2008 8:46 am

Sprat and Winkle couplings

Postby smyles » Sat May 14, 2011 3:44 pm

Have you any ideas as to how to fit 3mm Sprat and Winkle couplings to bogie rolling stock? I like to fit the couplings with the hook part below the headstock but the presence of a bogie seems to make it impossible.
Thanks,
Mike

Philip Hall
Posts: 1247
Joined: Mon Aug 10, 2009 7:49 pm

Re: Sprat and Winkle couplings

Postby Philip Hall » Sat May 14, 2011 6:14 pm

I've just looked at the only bogie vehicle I ever fitted these to ( a 56' coach) and I fixed the hook and 'paddle' to the floor just behind the buffer beam and cut away the centre part of the bogie stretcher at the coupling end, to leave room for the paddle to move up and down. I left the end cross beam of the bogie in place. I used curves down to 2'6" on the layout and it worked well as I recall. Coupling and uncoupling, though, was usually done on gentler curves or on the straight.

Philip

martin goodall
Posts: 984
Joined: Fri Oct 02, 2009 6:20 pm

Re: Sprat and Winkle couplings

Postby martin goodall » Wed May 18, 2011 10:05 am

Another quote from my unpublished article on 4mm auto-couplings:

"Probably the most popular magnetically operated auto-coupling currently in use is the ‘Sprat & Winkle’ type, now supplied by Model Signal Engineering. This design originated in the 1950s as the Hope & Nixon (H&N) coupling. Some modifications were later proposed by Harry Newcombe of the Epsom & Ewell MRC (see the March 1971 and November 1980 issues of Model Railway Constructor) and these various design features were brought together by Derek Mundy to create the ‘Sprat & Winkle’ coupling we know today. These couplings may appear rather conspicuous when viewing a single vehicle in isolation, but when in use on a layout they are not unduly obtrusive. The 3mm version of the coupling is often preferred by finescale modellers in 4mm scale to make these couplings less conspicuous.

The ‘Sprat & Winkle’ is a hook and bar coupling, in which the hook is pivoted, and is pulled down by the action of a magnet. The hook relies on a counter-weight in the form of a brass plate or ‘paddle’ to return it to its normal position after it is operated. Thus the resistance caused by any form of spring return is eliminated, although the form of pivot is somewhat crude, and the size of the counterweight can make it difficult to fit these couplings under some vehicles, especially bogie stock. Finally, as I observed in relation to the Alex Jackson coupling, the vertical pull exerted by a magnet on the dropper to pull down the hook does not seem to be so effective as the turning moment exerted when a pivoted dropper is attracted towards a magnet to raise a loop mounted on the same pivot.

The difficulty of fitting these couplings under vehicles, especially bogie vehicles, persuaded me that these couplings did not offer me what I was looking for."


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