Sergent Couplers

I’m trying to not get too excited about these…
Sergent S Couplers vs HO photo Sergent-S-Couplers_zps5663a6c6.jpg
(Three EC64 S scale couplers, plus one RC87 HO coupler for comparison)

Thanks to John Degnan, who alerted me to the existence of a Sergent Engineering Yahoo Group, I now know that the return of S scale prototype action couplers from Sergent Engineering is a step closer to happening.

Sergent used to offer S scale couplers as white metal kits. I used them on my On2 equipment when I embraced Maine two-foot railroading back in 2003. They were nicely designed but required a fair bit of fettling and my hobby skills were just not up to building couplers that operated consistently. Sometimes, I’d nail it and get beautiful couplers that operated smoothly and reliably. More often, however, I would get beautiful couplers that wouldn’t couple.

This was not an issue with the kits. It was an issue with my abilities to assemble something where finishes and tolerances matter.

But I loved how the couplers worked, and when Frank Sergent introduced his HO EN87A couplers – die-cast and pre-assembled – I bought them in bulk and converted over all of my On2 equipment. They worked wonderfully, even if they looked a little on the small side:
Quarry meet photo 8and21-SlatePile.jpg

On2 Boxcar 68 photo On2Box68-09_zpsb15dfaa3.jpg

Now that I’m building a standard gauge layout in S, I’m using Kadee S scale couplers. But I’d love to try the Sergent couplers again.

Why? Well, it’s not just an appearance thing. It’s also how the couplers operate.

With a steel ball used to lock the coupler, uncoupling is done with a small magnet on the end of a wand. One simply taps the wand to the top of the coupler and it’s ready to open. This, in my opinion, is much easier on the rolling stock than shoving an uncoupling tool into the knuckles and twisting.

It’s also easier to do under the layout lighting system I use. My lights cast very strong shadows, especially between coupled boxcars cars. Note how dark the freight car ends are this photo, compared to the sides, and imagine trying to see the couplers to insert a skewer:
Coupled boxcars photo Boxcars-CouplerDemo_zps0d65bf00.jpg

It’s not always easy. One has to thread an uncoupling pick straight down – not taking off the brake wheel or the associated end platform in the process – and insert it between the moving faces of the knuckles. Often as not, the tool ends up between the moving face of one coupler and the back of the knuckle on the other. It can be a bit like spearing the last olive in the jar – but with the lights out.

With Sergent couplers, such feats of eye-hand coordination aren’t necessary. In fact, one could introduce the magnet to the couplers from the side, since it doesn’t need to be inserted between the knuckles. That’s a whole different order of easy.

My understanding is that Sergent Engineering has been working to re-introduce the S scale couplers in a design that’s easier to build. This has been rumoured for quite a while, but – quite understandably – the S scale couplers are a niche product compared to Sergent’s HO offerings and like many things in this hobby, the expected release date kept getting pushed out as Sergent Engineering focussed on introducing new products for its primary market.

There’s still no definitive word on the status of S scale Sergent couplers. But the lead photo – posted by Frank to the Yahoo group – shows that the new coupler design looks similar to the HO die-cast version, with a solid shank with insert instead of a shank built from two halves. I’m pleased to see that – it offers hope that these new couplers will be easier to build and that the finished couplers will be more consistently reliable.

If and when the new couplers arrive, I’ll buy some and if I can get them to work, I’ll buy more. Of course, if they’re offered pre-assembled, I’ll order them in bulk and do a complete switch over.

If you want to know more, I suggest joining the Sergent Engineering Yahoo Group to watch for updates.

10 thoughts on “Sergent Couplers

  1. They are beautiful. Seems this has been a real hot topic in the short time I’ve been in S scale. One can only hope. At this stage, my fleet is small enough that a wholesale change over would be very “do-able”, so I’ll keep my fingers crossed. Thanks for the update.

    Mark in Oregon

  2. I found these (at least in HO) to be very time-consuming to use. They have no (unprototypical) centering springs so you need to take a lot of care in lining the couplers up prior to coupling. I have never been able to get them to couple consistently without being able to look directly down on to the couplers or up into a mirror above. This means that generally the layout has to be a little lower than I like (and certainly not at eye level — unless you’ve got continuous mirrors above).

    Uncoupling isn’t too bad with the magnetic wand.


    • Hi Seth:

      While I have heard of some people in HO using Sergents on large layouts, I’ve never experienced that first-hand. It certainly would slow down ops sessions if one needs to line up the couplers prior to coupling in, say, a classification yard. And it’s true that the gathering range of the Sergents is smaller than that of Kadees.

      But I used the HO scale couplers with great success on my On2 layout – a layout that had twice as many turnouts as the Port Rowan branch, and therefore twice as many potential coupling/uncoupling opportunities. They were no problem. The S scale couplers have a larger gathering range – akin, I would think, to an HO Kadee – so they should be easier to use.

      And I’m looking for opportunities to slow down the operation. Already, I encourage operators to stop short of coupling to give the brakeman a chance to pull a pin on a coupler – an action required for coupling. Everybody means to do this, but people often forget as they think about their next moves, etc. Sergents would force everybody to make the stop, every time – thus contributing to the realism of my otherwise very relaxed operating sessions.

      Good observations – thanks for sharing them. I suggest to readers who have not experienced Sergent Couplers and who are thinking about using them to buy a couple of pair and experiment before ordering in bulk. I’m already a fan, having done just that.


  3. Over here it’s very common to tape the uncoupling tool to a small flashlight or hand torch, which serves two purposes; one it makes it much easier to locate the tool and two it illuminates the dark area when needed.


    • Hi Terry:
      Great suggestion. I have flashlights to help with uncoupling.
      That said, I’m also concerned about threading an uncoupling tool past the brake wheels and end platforms on house cars. Sergents would solve that.

  4. More on these:

    Frank Sergent offered additional information on the Sergent Engineering Yahoo Group. He writes:

    I think the operational problems with the S scale coupler have been solved. I had to take about 0.002″ off the perimeter of the knuckle and they seem to work ok now. There are still some manufacturing issues that mean the sprue on the knuckle is more pronouced than I would like. After the sprue location is filed smooth, the couplers seem to work fine. I don’t know if I can solve this problem or not. If not, the knuckles will have to be filed as part of the assembly process. It’s not hard or critical, but it takes more time than I like. I had already decided that the S scale couplers would be offered in kit form only. I don’t have enough cheap labor (family members) to dedicate to assembly of these. All castings for the S scale coupler will be investment cast from 3D printed waxes. This means they will be MUCH easier to deal with than the old spin cast couplers.

    Thanks for the update, Frank – much appreciated!

  5. Trevor:

    I wasn’t aware of the wider gather range in S which I’m sure goes a long way towards easier coupling! My main concern was not so much about the time, as fine scale operation is supposed to have a slower pace, but the implications for sight lines. OTOH if the gather range is greater it may not matter. I have the impression that Port Rowan is built close to eye level and that would be an issue with HO couplers.

    • Hi Seth:
      Actually, railhead is 48″ from the floor in most places on the layout. As I’ve noted previously on this blog, the choice was dictated by several “givens” in the room, but it works well for me. A little lower than eye-level – perhaps chest-level? – but it works.
      While it’s been a few years since I used them, my recollection is that the S scale Sergents had a gathering range roughly the same as the long-time HO scale standard, the Kadee 5 coupler.
      Good observations. Thanks!

  6. A further update from Frank Sergent, who answered various questions about the new S scale couplers via the Sergent Engineering Yahoo Group:

    1. When will it be available? Probably late January (2014). No promises though. It has to be right first.

    2. Metal or Plastic? Metal. The 3D printing process provides plastic that I investment cast to turn it into metal. The metal is a zinc aluminum alloy not far from what the die cast couplers are made of.

    3. Assembly Fixture? No fixture will be available. Are you kidding? These things are HUGE.

    4. How many in a pack? Don’t know yet. I haven’t thought much about it. I haven’t thought much about the price either. I’ll have to sharpen my pencil there because 3D printing cost is based on volume and as some one pointed out these are 2 1/2 times bigger than the HO couplers by volume.

Leave a Reply

Your email address will not be published. Required fields are marked *

Please prove you're not a nasty spamming robot thingy * Time limit is exhausted. Please reload CAPTCHA.

This site uses Akismet to reduce spam. Learn how your comment data is processed.