AJs - hinge vs traditional

[nberrington]

Hi all

I’m trying to make sense of my coupling smorgasbord- a mixture of Dingham’s, AJs and kadees.

Most of my stock has AJs - fixed to the floor and relying on the inherent spring of the wire. I do however see lots of folks using the hinge type.

Does the hinge offer any particular advantage? It looks tricky to set up and the old fashioned version is pretty easy to do....

[Winander]

Seems there's only you and me awake at this hour...

Do you have MRJ 223 where Chris Pendlenton (of North Shields fame) "describes his experiences with the Alex Jackson coupling". It's a useful read as you would expect from him.

[nberrington]

Seems there's only you and me awake at this hour...

Do you have MRJ 223 where Chris Pendlenton (of North Shields fame) "describes his experiences with the Alex Jackson coupling". It's a useful read as you would expect from him.

I’ll dig it out, thanks!

[martin goodall]

Having messed around with various different auto-couplings over the years, ending up by devising my own design, I came to the conclusion that relying on a whippy wire being sprung down, either by engaging with an opposing coupling or by the magnetic pull of an uncoupler, is inherently unreliable. It is very difficult to get the tension just right, and getting the wire to spring back in the right place is equally problematic.

It was for this reason that I abandoned the use of a whippy wire in favour of a hinged arrangement. I have never got on with AJ couplings when operating friends' layouts and so have never attempted to fit them myself, but I was interested to see that some users of AJs had also resorted to a hinged arrangement in preference to springing down a whippy wire, no doubt for the reasons mentioned above.

I would personally go further, and say that opposed hooks pose problems in themselves, which is why I prefer a hook and loop arrangement. I have previously written up on this forum the basic design of my 'Burford' coupling. Since then I have refined the design further, with etched mounting brackets so that the bent wire components are now confined to the coupling hook and coupling loop alone, plus a delay latch and the stops to hold the couplings level, and a soft iron magnetic dropper. (For a glance at the final pre-preproduction version, see my 'Burford Branch' thread where I illustrated these couplings last April.)

I appreciate that quite a few people may prefer to stick to the opposed hooks of the AJ design, but hinged hooks strike me as a better bet than the original sprung version.

[JFS]

It has been a while since we all fell-out about couplings but inevitably it comes round again!! Every one has their reason for what they choose to use - there are those for whom wrestling with 3-links is the essence of model railways (just as there are thise who enjoy watching cricket). For the rest of us some kind of Auto is a lesser evil.

But it all depends on the kind of railway you have and how you want operate. Is it essential that the same coupling is used throughout - for example, how often will you couple your 3F to your Pullman rake? After all, A4s had Buckeyes (strictly drop-heads) on their corridor tenders as did Maunsell coaching stock fitted with Pullman gangways.

My layout features Southern EMUs and splitting and coupling is the main feature of operation and I use AJs for this. My reasoning is that they are unobtrusive, they work reasonably reliably and there are relatively few of them so maintenance is not a big burden.

If my layout was a large marshalling yard with hundreds of wagons I would probaly choose a different route.

Specifically on AJs, I think not everyone really understands how they are intended to work - specifically the "remote uncoupling" feature. In otherwords, you can back a train of wagons over an uncoupling magnet and, without stopping the train, operate the magnet under any number of wagons, which uncouple and remain uncoupled even when they pass beyond the magnet. You then end up with an (apparently) single rake of wagons which is actually split into a number of "cuts" each of which can be drawn-off by the loco to be shunted to other sidings. This feature is the essence of the AJ, yet I don't think I have seen that feature used other than on a tiny number of ocassions over the many years I have been playing trains - mostly, I see trains being stopped over a magnet and the rake split whilst the magnet is still energised. Many other coupling systems cannot reliably deliver this functionallity, but if it is not something you need to do on your layout, why worry?

And that leads me to my personal answer to your specific question. My experince of hinged AJs goes back to my previous layout where wagons featured (slightly) more.
The problem of the hinge is that it makes the coupling much less flexible laterally, this means that, when the magnet pull the coupling down, it will sometimes/often drag down its mate so that, when the magnet is off, or the rake passes beyond it, both couplings rise again having not actually disengaged.

However, if you can live with the consequences of that - for example if you do not need to use remote uncoupling and you don't mind doing an occasional double shuffle to shake two couplings apart - then the hinge means that the couplings are much less likely to get out of adjustment. This leads to a massive reduction in the maintence burden as it makes the couplings much easier to set-up and adjust. If you have a big fleet of wagons, that might be the killer factor of you.

So there is no domatic answer - except to say that Winander is spot on - Chris Pendlenton's article is masterly - he has a thorough understanding of the fundamentals, his research is comprehensive and his communication skills first-rate. He wrote the most economic sentence I ever read in a model railway article:- "Beware foam; it catches"

Do (exactly) as Chris says and you will not go far wrong.

[davebradwell]

Surely the biggest influence on choice of coupling is those you will be playing trains with. If your friends use a/js then there's no point in turning up with Dinghams, although you can always resort to a 3 link on occasions.

Reinforcing what has already been said, the original A/J coupling hanging in mid air is very susceptible to mis-alignment and the improved support suggested in Chris's MRJ article is a game-changer as Howard indicates. It won't eliminate occasional adjustment completely but goes a long way. Best way to reduce A/J maintenance is to eliminate derailments as this is when couplings are most likely to get bent out of alignment. Making them couple is relatively easy, getting reliable uncoupling by magnet takes a careful read of MRJ 223.

DaveB

[Rdunning]

I've used both traditional and hinged type AJ's on freight and carriage stock. The hinged variety is particularly suited to unfitted goods wagons and works well on coach bogies as the required amount of vertical movement for successful uncoupling is easier to obtain with these I find. A piece of syringe tube for the pivot can be soldered to the bogie frame or bolster. It's more difficult to find room under some vacuum fitted vehicles for the mounting block amongst all the brake gear and vac cylinders, especially those with SR "Freighter" 8-shoe brakes and the like, so I tend to fit the traditional type to such wagons.
The hinged AJ's can be set up very precisely, separately in vertical and horizontal planes, and retain their setting better by virtue of their robust mounting in the pivot tube or bracket.
Making, fitting and setting AJ's is undoubtedly much easier if you use the various Palatine jigs designed by Graham Turner and available from the Stores.

[nigelcliffe]

My experience is that its the pulling post (I think that's described in Chris P's MRJ article) which makes the biggest difference. That shifts the point at which the coupling pulls the wagon towards the buffer beam, which is particularly important on shorter wheelbase wagons. Whereas the hinge places the pulling position in about the middle of the wagon, and the sprung wire can be the opposite buffer beam. That shift in pulling position alters the tendency to twist wagons around on themselves.

Uncoupling, yes, should be as JFS describes.


There is also the minority interest, which I started, in fitting AJ's onboard locos which are controlled by a DCC decoder function output. It has its uses - primarily in loco hauled stock arriving in a run-round loop not always having to move forwards to reach the uncoupler - but those advantages are in a limited set of operations.


- Nigel

[Winander]

Happened upon these recently which may be of interest - a 'three link' looking dropper with an iron bottom link
http://www.lanarkshiremodels.com/lanarkshiremodelsandsupplieswebsite_179.htm

lanarkshiremodelsandsupplieswebsite179001.jpg

[Chris Pendlenton]

Encouraged by these sudden references to my article in MRJ 223 (and thanks to Howard for his kind words) might I just make a couple of comments. I tried the hinged method but with about 150 wagons in stock I thought they represented a deal of extra work. I agree with the point made that the location of the hinge constrains the lateral flexibility which will not be helpful to reliable uncoupling. As I have said in the article the dimensions and flexibility specifications of the original design should not lightly be tampered with. Another aspect is that it would be vital to get hinge bearings that are a sufficiently snug fit over the 11 thou wire to prevent any slackness which would introduce uncertain centrality of the coupling nose, a feature that must be maintained.
I have also tried the magnetic three link hooks suspended from the coupler wire (home made) but while a fine visual adjunct where coupling only is required, I found that uncoupling could be confounded by both sets of links being drawn down together, being too close to one another. Distance between opposing droppers is another one of those dimensional sweet spots that Alex sussed.
Another point about maintaining adjustment is that you should check your buffer stops whose transverse beam may well clout the coupler nose and need to have clearance established at its bottom edge.

Chris P

[Tony W]

As JFS said it has indeed been a while since we all fell-out about couplings. I have to admit that as time passes I've become much more tolerant of others views on the subject. Couplings are like types of paint or glues. We can get on with some but find others impossible. I suppose it's what makes us human. However, this doesn't mean we don't all have our own views on the subject!!

I'm a little confused as to the wire that Martin Goodall states he was using, particularly as he, "abandoned the use of a whippy wire in favour of a hinged arrangement". This seems to suggest that the 'whippy wire' was used only for the traditional coupling. If wire such as a guitar string is used it surely doesn't matter if it is used in a hinged or traditional coupling?

JFS wrote:
The problem of the hinge is that it makes the coupling much less flexible laterally, this means that, when the magnet pull the coupling down, it will sometimes/often drag down its mate so that, when the magnet is off, or the rake passes beyond it, both couplings rise again having not actually disengaged.

Really? I'm not sure about this and I've never come across the problem even though both yourself and Chris raise the issue. If the correct type of wire is used to form the coupling, its inherent springiness and the amount of lateral movement required will surely make the type of coupling irrelevant. However, a problem has been identified....? Howard, I'm assuming you will have deburred the wire before forming the coupling. I made that mistake in Normans workshop once. Even my then much younger eyes couldn't see any burr but I only ever made that mistake once! I'm almost certain your issue will be caused by the counterbalance fitted to stock being too light in relation to the dropper, creating an almost balanced effect. This can, of course, be changed by increasing the weight of the counterbalance or by moving it further away from the hinge thereby creating a greater moment. It doesn't need much!! Apologies if you've tried these.

nigelcliffe wrote:
There is also the minority interest, which I started, in fitting AJ's onboard locos which are controlled by a DCC decoder function output.

For those of you who still haven't see this do look it up, its brilliant.

Chris Pendlenton wrote:
Another point about maintaining adjustment is that you should check your buffer stops whose transverse beam may well clout the coupler nose and need to have clearance established at its bottom edge.

For those who are contemplating fitting AJ Couplings to their stock but think they can avoid fitting height bars by using the underside of the buffer beam (headstock) instead, please read the above quote again. Without a height bar your coupling nose will be closer to buffer height than is desirable and you could be introducing unnecessary problems, the above being just one example. For those without problems - congratulations!!

If anybody is wanting a little more information on the Alex Jackson Coupling the original text, which is updated from time to time, is still just as relevant today as it ever was. It does prevent some from re-inventing the wheel despite numerous attempts through the years - its just that some don't appear to have ever read it. This can be found at https://www.mmrs.co.uk/technical-articles/alex-jackson-coupling/

I'd like to conclude by thanking JFS for reminding us what Chris Pendlenton said in his article - "Beware foam; it catches". In my years of demonstrating AJ Couplings I can honestly say that foam used incorrectly is the No1 culprit for causing maintenance issues!!

Tony

[martin goodall]

In response to Tony, I was using guitar wire (either 11 gauge or 12 gauge – I forget which, although I suspect it was 12 gauge), and the couplings I was experimenting with at that time were a variant of AJs, where the hook wire engaged with a fixed loop on the opposing vehicle.

I appreciate that my remarks are really of no help to those who are determined to persevere with AJs, but the further discussion on this topic seems to me to confirm the problem with using the opposed hooks of AJs, which have to flex not only vertically but also horizontally when coupling or uncoupling vehicles.

It was this that led me to prefer a hook and loop arrangement, rather than the opposed hooks of the AJ coupling. Another point, which I think arises from what Chris Pendlenton has said about hinged hooks, is that arranging a pivot of the hook wire without any sideways ‘slop’ is not easy. It was for that reason, having chosen to use a hook and loop, that I decided it would be easier and more reliable to pivot the loop, whereas the hook wire should be fixed.

Various commercially available couplings, such as the DG and Dingham, also use a fixed hook and pivoted loop, although I had reservations about the design of the delay latches used for advance uncoupling and sought to devise a more reliable alternative.

My apologies to everyone who wants to concentrate exclusively on fixing the problems with AJ couplings, and who may find my irrelevant wittering unhelpful. (Just ignore me.)

[steve howe]

Just for info, a similar thread is running on Western Thunder:

https://www.westernthunder.co.uk/threads/alex-jackson-couplings-question.11265/#post-266930

Steve

[JFS]

JFS wrote:
The problem of the hinge is that it makes the coupling much less flexible laterally,

Really?

Self-evidently so - since the length of wire from the hinge to the hook is so much less than a full length AJ.

Howard, I'm assuming you will have deburred the wire before forming the coupling.
Tony

It was decades ago Tony and there were plenty of other things wrong with that layout! At the time, I saw the hinge as the answer to every maiden's prayer, and I by no means condemn it now. However, once I read Chris' article I saw his approach - including the Pulling Post - as a much better way forward. Hence me using it now. BUT I reiterate what I said at the start - my layout is Passenger only - not a hundred and fifty wagons! For such expertise I am happy to pass over to Chris.

All that said, I accidentally discovered the perfect coupling at when exhibiting at Scaleforum 5 years ago. In our operating sequence, there is a move where a pair of 2-BIL units arrive, then split. They subsequently depart separately to be recoupled in the FY. Having adjusted the couplings before the show, I was gratified to see the uncoupling was 100% over the dozens of times we made the move. Late on the Sunday, the truth came out - the rear unit derailed on the fiddle cassette and stopped dead as it come into view. Meanwhile the front unit carried on regardless. In fact the two units had never been coupled the whole weekend, but (being DC) the rear unit was slightly pushing the front one so giving every appearance of being coupled ... !!
The system worked so well, we retained it for the Epsom show!

Well, it works for me!

Best Wishes,

[nberrington]

Sorry all, didn’t mean to set off an old debate.

The problem is (as always), when there are multiple competing options, then there is no ideal option.

I’m trying to rationalize what I do a bit. Dinghams work quite well, but I don’t care for the appearance too much- Kadees even more so - very easy to install, seemingly reliable, but a major compromise. Scale 3 links and screw coupling look fantastic, but won’t help me much as I would need to lean over the layout to couple any trains on the main platform.

So here I am scratching my head at my multiple different couplings on my stock. Most have AJs from years ago, and work OK, considering they are ageing and were bent with some very early iterations of the jig. (Mostly made by eye really, and still sort of work) The newer jigs might be more precise - I guess I will find out soon enough!

I appreciate the wealth of experience and advice given here on the forum. I guess the truth of the matter will emerge during real deployment - I.e. once the layout is more than an up and down shuffle and some serious shunting needs to happen.

In my day job we often talk about the “best way” to do something, but in truth it really depends what works for you - specifically how will this work out in my hands, as the nearest help is, ... well, .... there isn’t really anything remotely close to me!

Thanks again everyone.

[Tony W]

Martin Goodall wrote:
Another point, which I think arises from what Chris Pendlenton has said about hinged hooks, is that arranging a pivot of the hook wire without any sideways ‘slop’ is not easy.

Thanks for clarifying what you meant Martin, its appreciated. However, I've got to respond to your comment about sideways slop. I'm sorry but its dead, dead easy to eliminate all sideways slop......providing the wire passes through a correctly sized pivot hole or holes. On page 3 of the MMRS missive Norman Whitnall used 23 gauge hypodermic needle to manufacture hinges. 11 thou wire gives a really smooth fit in the needle and the 90 degree bend at the end is achieved by bending against the needle itself. It's made of steel so no harm will come to it. I tend to now always use the Palatine pivot plates wherever possible but if I make the pivot hole too big (usually by not seating the drill bit correctly in the chuck I still resort to hypodermic needle to rectify the situation! I think we're all guilty of trying to reinvent the wheel sometimes!!

JFS wrote:
Well, it works for me!

I think, Howard, these words should be hung above all forum threads My wife's yoga instructor says, "there's no right or wrong way of doing it, it's what works for you". The trouble seems to come when the way that works for you goes wrong, but that's a different story!

Tony

[JFS]

Sorry all, didn’t mean to set off an old debate.

Absolutely no need for apology! We all love these debates and if questions never get asked, no one ever challenges themselves. And I think we are all good mates BECAUSE we fall out not despite it

I think, Howard, these words should be hung above all forum threads

I absolutely agree Tony. And I would add a further bit of tangential but relevant personal learning. For several years I had the pleasure to demonstrate track building at a number of Society events. People would sit in front of me and say "I really like your trackwork: tell me how do you do your ... ?" For quite a while I made the mistake of answering their questions. I then realised that my correct response should be to ask "What are you trying to achieve and what experience have you had so far? Armed with their reponses, my next utterance was very often, "Well, if I were you, I would not do it my way ... "

Best Wishes,

[steve howe]

On page 3 of the MMRS missive Norman Whitnall used 23 gauge hypodermic needle to manufacture hinges.
Tony

Hi Tony,

What do you recommend to cut hypo needle tube?

Steve

[ralphrobertson]

What do you recommend to cut hypo needle tube?

Steve, a Dremel accessory is the best thing I ever bought for cutting anything. The mandrel locks any cutting wheel permanently and the cutting wheels last forever, I have never had one break and I have one worn one down close to the mandrel before I replaced it - and that was years. I also use it for cutting piano wire and tubing, I would not be without mine.

Take a look, it will cut the hypodermic needle easily.

https://www.dremel.com/gb/en/p/dremel-ez-speedclic-starter-set-2615s406jc