Chopper couplings

[BryanW]

I am relatively new to garden railway modelling having been (and still involved in) S4 for over 40 years. A chance purchase of a "complete garden railway train set" last year and its building - at least to a basic oval - this year has opened up a new and exciting world. That is apart from one thing - couplings, or rather the apparent absence of any that couple and uncouple automatically. With my S4 model I am used to having stock couple and uncouple using Alex Jackson couplings (not the easiest to set up but wonderful when they do work) and it was a surprise therefore to find that in a scale that is four times the size there wasn't something that "just worked". The stock I have came with the seemingly ubiquitous hook and chain and most other layouts I have seen and visited use the same. I like to do some shunting and have never got on with shunters poles and hands from the sky. I am therefore on the look out for something that looks reasonably prototypical but above all works reliably. I have dabbled with the Peckforton couplings described by Rik of this parish in his blog and although I have got them to work I find the phosphor bronze spring hook is too strong and the stock needs a good shove to get them to couple. Clearly they work for Rik but it may be that his stock is heavier, being on 45mm track rather than 32mm that stops then careering down the rails. I would continue to experiment with these using thinner wire for the coupling hooks, or maybe putting in several spring turns where the wire leaves the brass bracket but ultimately these couplings do not satisfy my wish to have automatic uncoupling.
The one I have seen recently, although the video showing them is some years old, is on the Hambleden Valley Railway by Steve Howard. The You Tube Videos of this show shunting operations being carried out by live steam locos running slowly (with SloMo devices fitted) and TenMille chopper couplings which seem to have been adapted to have an extra "leg" with a small neodymium magnet attached. This is operated (magnetically attracted) to a larger magnet in the track bed when the stock is not under tension. I have tried to find more details of this system - which performs very well and would suit my needs - but have failed. I do note that the stock is "handed" with a hook only on one end. As I do not have any return loops or turntable this does not present a problem for me.
So, and with apologies for the length of this post, my questions. Does anyone know the details of the modification? Are Tenmille the only chopper couplings out there suitable for this modification? Will they (reliably) couple with other chopper couplings (eg Swift Sixteen, Accucraft, Slaters etc)? I realise these couplings are not cheap (£10 plus per pair seems to be the going rate) and with over 20 items of stock to "convert" I don't want to invest over £200 on something that may not perform satisfactorily.
Many thanks in anticipation of your replies.

Bryan

[philipy]

Hi Bryan,
I can't answer your basic question about a write up of that specific layout/coupling system. However what I can say is that the subject does crop up from time to time on here and individuals ( including me) have a play at trying to achieve reliable Alex Jackson type operations. As far as I know, only Rik and a former member, Tom-Tom-Go, have come close, but to my knowledge there are no commercially available systems even from Cottage Industry suppliers apart from the versions fitted by some big continental train manufacturers but which I know nothing about.

I think a large part of the problem has to do with wheel and track standards. Th fine tolerances of P4/S4 allow for accurate positioning of the 10thou Alex Jackson wire which even then can be a *%$@#~ to set up. In 32/45, the standards are so much looser and curves, wheelbases and overhangs, so much more variable, that it simply doesn't work for most of us.