Greenwich Couplings

[berryr99]

I know this is an old topic but it is new to me.

I have got an incredibly silly question but my learning curve is vertical on the topic.

Do I need to fit Greenwich Couplings to the loco or will the coupling on the stock be able to lift and uncouple over the magnet.

In other words do they only work in pairs ?

Thanks

Robert

[JulienW]

They uncouple because the magnet below the track pulls down on the coil of iron wire on the tail of the coupling loop, which pivots and lifts the business end of the loop up off the pin on the adjacent coupling.

Because of this you only really need one loop and one pin to link up any two vehicles. Quite a number of people use these type of couplings with the loops only fitted on on end of their stock (the other end just has the buffer with the pin), including the locos as this removes the possibility of having two loops getting tangled up and not uncoupling. The disadvantage is that you must put the stock on the track the right way around to avoid having two 'loopless' couplings trying to couple up! The other convention is that loops are fitted to both ends of the stock and locos have buffers with a pin front and back, but no loops.

Whichever system you chose (loops on all stock, or loops on one end) it is vital to get the heights of all the couplings the same, and have them aligned on the center line of the stock (i.e. not offset).

Edit:  I've re-read your initial question and my answer above and realised that I might not have been clear with my answer (feeling a little under the weather with some lurghy).

Essentially if you wanted to use the couplings supplied in the loco kit with Greenwich couplings fitted to the stock you can as long as it has some sort of pin / peg for the loop of the Greenwich coupling to drop over, and it helps if  the kit coupling on the loco is set to the same height as the Greenwich ones on the stock.  However, if you choose to go down the route of fitting Greenwich couplings with the loops only fitted at one end then you will also need to fit a loop to one end of the locos, and probably the easiest way to do that is to replace the kit's couplings with Greenwich ones (at least on one end).

Hopefully that's a bit more helpful?

[Darren Hedges]

Hi Robert.

I did answer a few questions regarding Greenwich couplings at the Tyne Tees members day but i'm afraid i can't remember who with, was it you?

Regards,
Darren.

[berryr99]

Darren,

Yes it was me but I forgot to ask the questions that I'm asking here !

Thanks for your help - convinced me to go for Greenwich couplings

Robert

[B.Meldon]

As has been said in the above posts the coupling height is critical.

G&DNGRS produce a height gauge for their couplings that you can use if you wish. This can also be used to adjust the coupling height on kits and RTR locos and rolling stock. You will find that many 009 and H0e items have couplings that are set at different heights and will need adjusting to make them work correctly with the Greenwich couplings.

(This is the same if you use normal Egger/Bemo couplings, many items, even RTR need adjusting to get them all at the same height.)

Brian Meldon

[JulienW]

As has been said in the above posts the coupling height is critical.

G&DNGRS produce a height gauge for their couplings that you can use if you wish. This can also be used to adjust the coupling height on kits and RTR locos and rolling stock. You will find that many 009 and H0e items have couplings that are set at different heights and will need adjusting to make them work correctly with the Greenwich couplings.

(This is the same if you use normal Egger/Bemo couplings, many items, even RTR need adjusting to get them all at the same height.)

Brian Meldon

As an alternative to the Greenwich etched plate (which has other uses too  - like setting the magnets to the right depth IIRC) RT Models make a cast resin jig (catalog no. NGWC010, see http://www.rtmodels.co.uk/rt_models_017.htm) which as the advantage that you can't inadvertantly 'tip' the jig to one side and get the coupling too low.

[berryr99]

I have started to make some Greenwich couplings but I now have a couple (no pun intended !) of questions

1. The tail on the loop. It looks like I have to cut this down for 6mm (009) coupling height 2mm up from the end of the tail. Is this correct ?

2. The wire goes round the tail and then the instructions say to bend the tail under at 90 degrees. Is this correct as it is not mentioned on the You Tube video ?

Thanks

Robert

[Krizzy]

Robert

I have used Geenwich Couplings many times, it is not really necessary to cut down the 'tail'. It is bent to 90 degrees under the shank with the soft iron then attached. I wrap the wire round about 6 or 7 times using fine pointed tweezers. Just make sure the bent tail does not catch on the track especially on pointwork. I no longer use the steel pins provided but use soft brass wire instead obtained from a craft shop such as Hobby Craft. The holes may need to be reamed out a little with a cutting broach. Try to mount the couplings at the same height, top of buffing plate 6mm above the rail, then they should couple up to most other stock. Greenwich also produce a height gauge as well as RT Models which is a convenient resin block to plant on a length of track to check all coupling heights.

Roger

[Elmgate]

To clarify - the tail can be made two lengths, to allow for different coupling heights. At the circa 6mm height normally used by 009 modellers, if you do not remove the last 2mm, it is still advisable to bend at the shorter point, and thus have about 4mm in the horizontal - by removing the extra 2mm, the horizontal is shorter. When used with, for example, 12mm gauge or larger scales, the coupling may be set circa 8mm high, and the tail is bent at the longer point, leaving only 2mm horizontal. But, as Roger says, the choice is yours.

[Frank]

When wrapping the iron wire around the tail, I lay the first piece along the tail with the loose end hanging over the end of the tail by about half a cm.  then wrap the other end around the tail starting at the end nearest the loop, thus trapping the wire on the tail, then when the tail is wrapped the wire can be secured by just twisting the two end together and trimming to length.  No glue needed.

Frank

[berryr99]

Thanks to all.

Now I understand.

Roger, I should have paid more attention to your demo at the convention !

Robert

[Andre Anderson]

Greetings,

As I am new to both OO9 and English narrow gauge, does the Greenwich Coupling have a basis in reality, I guess what I am asking is "Is it a scale coupler or is it one designed to work well?". If not a semi scale coupler what would be a good scale coupler? What is the problem with having two loops? Wouldn't you need two loops for when the cars get turned around? Or is it a case that the railways were so short and there were no wyes to turn cars so they always faced the same way?

Andre Anderson
Portland Oregon USA

[invercloy]

Andre,

I'm not aware of a prototype, but will bow to others experience on that one...

I run Greenwich couplings on my layout, I have hooks on either end of the layout, and loops on either end of items of rolling stock. This is because locos on my layout will eventually get turned. I have no issue uncoupling using two loops, but i've done it because of loco turning, not items of stock.

When operating the magnets supplied with the couplings I found they were too strong and attracted items of stock with metal wheels towards them. I experimented a little and bought some neodymium magnets of a lower strength, they work well, fit between the sleepers of Peco Mainline 009 track and still enable uncoupling whist being weak enough to not attract stock - if you're interested in more details i'll see if i can find a link to the supplier.

[JulienW]

I can't think of a full size coupling that uses a pivoted loop on a center buffer that hooks over a 'peg' on the adjacent coupling Andre.  The closest are link and pin (horizontal slot in the buffer face which a link from the adjacent buffer fits into and is secured by a pin dropped in vertically) and Norwegian / Chopper coupling (buffer has a hook which drops into a vertical slot on the adjacent coupling and hooks over a horizontal bar) - and the Greenwhich (and others) are, in a way a combination of the two - essentially 'designed to work well' as you put it.

For our model railways some people only fit the loops to one end of their stock to avoid issues of loops clashing (both loops lift but do not drop to couple up) or getting tangled in one another (and therefore not uncoupling). Personally I've not had that problem.

Coming back to Full-size UK practice one has to remember that there is generally much less 'space' available to build railways so wyes (triangles) specifically for turning stock were very few - in fact I'm hard-pressed to think of an example but I'm sure someone will come up with one - with turntables being used, and even then few lines would have had one of those either.

As to 'a good scale coupler' there are people who make 'scale' chopper couplings (Meridian might still do, likewise Branchlines) but they are not too easy to make up and just as hard to use - which if you plan to do a lot of shunting can be a pain. Very few 009 modellers use them, and the Greenwich type, along with the other 'lifting loop' types (Bemo, Windle, DG) are very popular, and have the added advantage of all being able to couple to one another if set at the same height.

[B.Meldon]

The Greenwich coupling is designed to work well. There is no prototype on the real railways.

In the world of UK narrow gauge railways there are probably as many different couplings in use as there are railways! Chopper couplings, and link and pit types are common, but I have also seen caravan type toe balls used! However in practice very few are the same and when locos visit other railways their couplings almost always need changing or an adapter of some type is required. I do not think any UK NG lines use knuckle couplings.
The problem is that making any of the prototype couplings in use in the UK work automatically in model form is virtually impossible and as mentioned above even making them work with manual intervention is not at all easy.

In model form the lifting loop and fixed pin type couplings originate with Marklin