Wednesday, 25 April 2012


You can call me a masochist, and you might be right. Because I am one of those strange people who choose to use three-link couplings on their railway models.

I made this decision many, many years ago on the basis that most of the proprietary auto-couplers make a lovingly-constructed and decorated model look more like a toy. And in my early modelling days, construction was mainly from kits, for display and photography, so auto-couplers provided little benefit.

The difficulty was finding a three-link coupling which looked correct and worked reliably. I have a box filled with examples from every conceivable manufacturer, many of who have long since gone out of business. All have one thing in common; they fail to meet one or both of these requirements.

Over the years, experience has softened my resolve a little. Freight stock must have realistic couplings. Passenger coaches with gangway connections are less critical. Firstly, they are usually connected semi-permanently into sets. Secondly, the gangway connection largely hides the coupling. Thirdly, the same gangway connections make coupling up a three-link coupling all but impossible. So an alternative is needed, with an added requirement for realistically close coupling.

So, where do I find suitable couplings. Well, the only three-link couplings to have come close to meeting my requirements are those supplied by Exactoscale. They look right, are made to tight tolerances which so far have been consistent, are not too difficult to assemble, and work reliably if care is taken in fitting to keep a constant and pre-refined dimension between buffer face and hook. You need to work out this dimension for yourself, based on the smallest radius track curve you want to cater for, the length and wheel-spacing of the vehicle, and whether or not the coupling hook and/or buffers are sprung. It needs to allow the coupled vehicles to get round your worst curves without the buffer binding, but not be further apart than necessary at other times.

Exactoscale provide instanter links as well as standard links, and the first picture shows one of these fitted to a Bachmann 9' wheelbase wagon.

A Bachmann wagon with instanter-link coupling chain and hook by Exactoscale.

Given that most proprietary models are now to at least as high a standard as most kits, and not very different in price, wouldn't it be nice if they were already fitted with a scale coupling hook? Well, Bachmann have achieved this on some of their recent models. The next picture shows Exactoscale coupling chain on the original hook of a Bachmann 16T mineral wagon. All that was required was to ease the two chain apertures slightly to ensure free movement, and it works perfectly. Don't get too excited though, as most Bachmann hooks are too thick or the wrong shape.

A Bachmann wagon with Exactoscale chain on original Bachmann hook.

As you've probably noticed, I have so far avoided the thorny subject of screw couplings. I solve the problem on freight stock by using instanter links on "XP" rated vehicles. On locos, I use Hornby screw couplings. They are the best-looking I have found, and the hook works well with the Exactocale links from other vehicles. However, I regard the Hornby chain as cosmetic only (and they are sold as such), so I only fit them to locos. If I want to couple two locos together, I use a set of loose links.

A Bachmann loco with Hornby dummy screw-link coupling.

Finally coaches. I don't have one single solution for coaches. To date I have used the supplied tension-lock coupling, but they require between 1 and 2mm of slack to operate, so can never by their design  provide really close coupling. The best solution so far has been the alternative couplings supplied with some Hornby coaches. These fit into a clever mechanism under the coach which increases the gap when the vehicle goes round a curve, so on the straight they can actually have buffers and/or corridor gangway connections touching between coaches. Unfortunately, the manufacturers don't seem yet to have confidence in this mechanism, and still provide couplings which are longer than necessary. This can be circumvented on Bachmann Mk1 coaches by using the Hornby couplings (see next picture), which are just the right length when coupled and have minimal slack. In fact thay are too close to couple by pushing the coaches together, and you need to gently push the coupling under the coach with a screw-driver or similar, until it clicks.

Compatible couplings are made by Roco, and are slightly shorter. They are ideal for the Hornby Maunsell coaches, with the same caveats as above. I haven't experimented with any other coach classes. You will also find that coupling a Maunsell to a Mk1 may be unreliable, as the NEM pocket on the Bachmann Mk1 is not at the NEM specified height, and the supplied tension-lock couplings have a joggled arm to correct this.

A Bachmann Mk1 coach with Hornby Roco-type coupling.

How do I go about coupling and uncoupling our vehicles? The coaches, whenever practical can be kept together in sets. It helps if they can be stored on "cassettes". The three-link couplings I always make with a magnetic bottom link (Exactoscale supply these). This allows a magnetic pole to be used, available commercially from a number of sources, or made with a tiny magnet, a brass pole, and a miniature LED torch, all held together with epoxy adhesive.

I haven't mentioned cost yet. None of the solutions offered here is cheap. However, I have spent so much time and effort in the past on items that ended up being of little use, that I now just pay the money at the expense of some other item in the modelling budget, and don't worry too much about it.

This review still leaves some questions unanswered; for example, how to connect the loco and coaches. I am still looking for a consistent solution here, and in the meantime I assess each case separately, usually using a vehicle with a different coupling at each end as an interface. If you have any better ideas, let me know!


Three link coupling parts: Exactoscale Ltd 4CP D01A, 4CP 303A, 4CP 312A, 4CP 311A, available from

Cosmetic screw coupling: Hornby X5069 available from

Coach coupling: Hornby X8220 available from or Roco 40270 available from

Magnetic coupling pole: available from

Micro magnets: available from


  1. what gauge are the wagons and steam engine

    1. All of my modelling at present is in 4mm/ft (1/76) scale, 00 (16.5mm) gauge.