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Sprat & Winkle couplings


Mikkel

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Shunter George "Bulldog" Mullins critically eyes stock fitted with Sprat & Winkle couplings.

His shunter's pole is legendary among shunters for being rather crude!

 

The following notes on Sprat & Winkle couplings seemed to generate some interest when first posted over on gwr.org.uk, so perhaps they are of of use to someone here also. I have taken the opportunity to take some new and better photos for illustration.

 

 

Hooked

 

Although the latest RTR offerings have helped enhance the looks of the RTR tension-lock coupling considerably, I still find them a bit too bulky and not quite reliable. They also do not offer the opportunity of "delayed action" uncoupling, which allows you to propel stock forward after uncoupling.

 

Looking for an alternative, I have taken to the fairly well-known Sprat & Winkle coupling, which - although a compromise in some respects - has proved quite reliable and fairly easy to fit. I find the delayed-action feature of these couplings simple and effective, and a plus for me is that they allow cosmetic 3-links to be retained.

 

 

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Hook and bar. It could be argued that it is no less obtrusive than the modern tension-lock coupling.

But I find it less bulky and with more functionality.

 

 

One-hook operation

 

The Sprat & Winkle couplings are available in 2,3,4 and 7mm scale versions. As I model in 4mm my choice was between either the standard 4mm version or the "finescale" version. The latter is in fact intended for 3mm modellers but works fine for 4mm (including OO), as long as your curves are not too severe ( ie less than 4' radius according to MSE). This is fortunate because the standard version is a bit on the large side for my liking, and so I have opted for the finescale/3mm version.

 

In fact, even the finescale version is a bit more prominent than I would personally have wished for, especially when uncoupled. To minimize the visual impact I therefore fit a coupling hook to one end only, adding just the loop at the other end. This obviously requires stock to be facing in a particular direction when placed on the track, but on my layouts (and I think many others) this isn't really a problem. The absence of a coupling at one end also facilitates the fitting process (since you only have to fit one hook per wagon) and means I can add a prototypical (but cosmetic) coupling hook here instead, enhancing appearances a bit.

 

 

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Coupled up using the "one-hook" approach

 

 

Mounting the couplings

 

The coupling hook features a square "paddle" at one end, which works as a counterweight beneath the wagon or coach body. The MSE website has an instruction sheet for fitting the couplings, and details on various extra parts not described here (including custom-made mounting plates). The instructions suggest two possible ways of mounting the hook: An "Upper" method in which the coupling hook is inserted through the headstocks (ie the "buffer beam" of the wagon), and a "Lower" method in which the hook rests immediately below the headstocks, hinged to the wagon floor with wire bent to the shape of a paper staple.

 

It is necessary to standardize on one of these two methods, and in principle I prefer the latter, which also comes recommended in the instructions: This requires only minor modification to the wagon or coach body, and is also - in my opinion - rather less fiddly. That said, I have made two minor modifications to this approach:

 

* Firstly, I replace the curled-up wire included in the pack with straight brass wire from Alan Gibson. I find that this makes it far easier to craft the wire-staple needed for fitting the paddle. The staple is then fitted to a section of square plastic rod mounted on the wagon floor. The plastic rod is not always necessary - it depends on the distance between the floor and the lower edge of the headstocks.

 

* Secondly, I find that the "Lower" method of mounting the coupling can sometimes give problems in ensuring that the coupling hook is fully horisontal: Exactly because it is underhung, the hook may come to rest at a slight upward angle against the bar of the loop on some wagons, which is neither aesthetically pleasing nor good for operation. I don't think it's just me, as I have heard others mention this issue also. My solution is rather crude I suppose, but effective: I simply open out a slight slot in the wagon just above the coupling hook, thereby allowing it to move freely to a full horisontal position against the loop. This may not be to everyone's taste, but the slot is really quite unnoticeable and can always be padded over with a filler if the coupling is removed.

 

 

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The "Paddle", anchored with a wire "staple" to a supporting section of plastic rod

 

 

 

Un-coupling

 

Uncoupling is by means of magnets located beneath the track, nested into the track base. The magnets attract the 3-links, thus tilting the hook downwards. When moving back up, the hook comes to rest in a position which allows the wagon to be propelled forward and left where you want it in the siding. Hence the "delayed-action" concept. The following photos illustrate the four main steps of this process:

 

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1. Wagons are propelled in fully coupled condition

 

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2. Coupling hook drops down as it is attracted by a magnet beneath the tracks

 

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3. As wagons are propelled forward the coupling hook moves back up, but does not fully engage the bar

 

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4. The uncoupled wagon is left where desired, and the rest of train is drawn backwards

 

For me this works well, with one important modification: Because I use only one coupling hook, the very powerful magnets occasionally uncouple the stock even when they are not supposed to - ie when the stock is passing slowly by. This happens even with a good layer of ballast above the magnets, and attempts with a sliver of Plastikard above the magnet doesn't help much either.

 

Again, I resort to cave-man technology for the solution: I simply break the magnets in half, thereby reducing the overall magnetic field. I say "break" because cutting will get you nowhere with these magnets - they need to be broken in two by holding the magnet with one pair of pliers and breaking downwards with another pair. Crude stuff, but it works.

 

Finally, I should perhaps emphasize that I have no affiliation with the manufacturers, and that these are the experiments of a novice: I do not have experience with the other non-RTR types of couplings available (see jim s-w's blog for an interesting entry on the Dingham coupling).

 

Edit 1: For a discussion of fitting the couplings to locos, see the comments to this entry.

Edit 2: The video in the link below shows the Sprat & Winkles in operation on the goods depot layout:

 

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7 hours ago, Mikkel said:

Thanks Jeff and Michael, I will do that. I have another S&W fitting session coming up so will give it a go then (I seem to remember there was a reason I don't use the mounting plate, but I have forgotten why and it may be a myth created inside my head!).

 

In the same boat - I used them in my first go at S&W's but gave up on them for some forgotten reason and have managed successfully without them ever since.

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On 06/11/2009 at 05:44, Mikkel said:

Interesting Richard. I did initially consider leaving off the bar at the hook-end, but found that the hook would then be prone to tilt upwards (rather than remaining horizontal) . But maybe you have found a workaround to that?

 

Thought I'd better get round to replying to this one ...:blush_mini: I adjust the hook end position by bending the weighted paddle to suit. Once done it rarely need altering, usually only after a knock, and hasn't been a problem at all.

Edited by Ben Alder
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On 19/05/2019 at 12:24, JSpencer said:

I remember Sprat & Winkle when I was part of the Chatham club.

 

I am surprised that a NEM version does not now exist.  That would bring more converts.

 

It would certainly be nice, but maybe there aren't enough people who want to fit S&W couplings to RTR wagons  to make it worthwhile? A chicken and egg situation.

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Mikkel

Posted (edited)

On 19/05/2019 at 17:14, Ben Alder said:

 

Thought I'd better get round to replying to this one ...:blush_mini: I adjust the hook end position by bending the weighted paddle to suit. Once done it rarely need altering, usually only after a knock, and hasn't been a problem at all.

 

Good to know. I do find the S&Ws quite reliable, even with my fairly relaxed standards. 

 

And thanks for coming back to this. I'm trying to remember what has happened in the world since November 2009, but it's all a blur! :lol:

 

Edited by Mikkel
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It's important to ensure that the bars align, I usually set the height of these first (at 12mm above railtop) , then an just the hook, by bending gently half way along, so that the inside of the hook aligns with the bar. Also ensure that the bar is aligned with the buffer face to avoid buffer locking when propelling. I'm trying to develop a s&w coupling that will fit a nem pocket!

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Schooner

Posted (edited)

Hi @Mikkel (and the 202 other followers of this blog post),

 

Sorry for resurrecting what may seem like ancient history, but I was wondering if your process has changed over time? I'm not far off fitting S&W couplings to my stock, such as it is, and was wondering if there were any hints and tips further experience has brought. 

 

A little way off scattering horse poo about the layout, but when the time comes it'll be this blog I look to for information: there is nothing that isn't improved by a trip to Farthing :)

 

Cheers,

 

Schooner

Edited by Schooner
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I'm 10 years on from my comment in this thread (eek!) and I'm still well happy with S&Ws. I think I began fitting them around 2011, I've now converted a very large proportion of my rolling stock and locos, and have no real grumbles. I use the 3mm version on 4mm stock, and routinely propel trains around 30 inch (and tighter) curves without issue.

 

I put permanent magnets on my running lines as well as sidings, so trains have to be able to run through without anything uncoupling when it isn't wanted. Now and then I do get an issue with a guard's van or similar detaching from the end of the train, but while I wouldn't say I've cured the problem 100%, I find a combination of extra weight (to stop "waggle" at the end of the train, which allows the couplings to go momentarily slack) as well as the occasional use of friction brakes on the axles, helps make the problem infrequent enough that I can live with it.

 

 

 

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On 26/05/2019 at 18:34, Theo said:

I'm trying to develop a s&w coupling that will fit a nem pocket!

 

How did you get on with this? I'd be interested to know.

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Hi Schooner, my experiences are exactly as Al's/Barry Ten's. I have also rolled them out to all wagons by now - also using the 3mm ones -  and am happy with how they work. I haven't changed the way I fit them, as far as I remember. The only issue is that I struggle with fitting the 3-links sometimes. There's a post about that here, followed by some discussion:

 

https://www.rmweb.co.uk/community/index.php?/topic/97672-pragmatic-pre-grouping-mikkels-workbench/&do=findComment&comment=3999700

 

 

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