009 Society Members Forum

Modelling => Rolling stock => Topic started by: berryr99 on September 27, 2014, 11:18

Title: Greenwich Couplings
Post by: berryr99 on September 27, 2014, 11:18
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
Title: Re: Greenwich Couplings
Post by: JulienW on September 27, 2014, 11:41
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?
Title: Re: Greenwich Couplings
Post by: Darren Hedges on September 28, 2014, 02:10
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.
Title: Re: Greenwich Couplings
Post by: berryr99 on September 28, 2014, 16:53
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
Title: Re: Greenwich Couplings
Post by: B.Meldon on September 29, 2014, 09:48
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
Title: Re: Greenwich Couplings
Post by: JulienW on September 29, 2014, 10:42
Quote from: B.Meldon on September 29, 2014, 09:48
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.
Title: Re: Greenwich Couplings
Post by: berryr99 on November 25, 2014, 20:20
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
Title: Re: Greenwich Couplings
Post by: Krizzy on November 25, 2014, 20:42
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
Title: Re: Greenwich Couplings
Post by: Elmgate on November 26, 2014, 12:00
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.
Title: Re: Greenwich Couplings
Post by: Frank on November 26, 2014, 13:48
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
Title: Re: Greenwich Couplings
Post by: berryr99 on November 26, 2014, 15:27
Thanks to all.

Now I understand.

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

Robert
Title: Re: Greenwich Couplings
Post by: Andre Anderson on November 26, 2014, 21:48
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
Title: Re: Greenwich Couplings
Post by: invercloy on November 26, 2014, 22:37
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.
Title: Re: Greenwich Couplings
Post by: JulienW on November 27, 2014, 09:15
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.
Title: Re: Greenwich Couplings
Post by: B.Meldon on November 27, 2014, 09:58
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
Title: Re: Greenwich Couplings
Post by: Frank on November 27, 2014, 16:57
In the " proptotype for everything " department there is of course the Ashover Light Railway's turning triangle at the Ashover Butts end of the line.   

Frank

Title: Re: Greenwich Couplings
Post by: Andre Anderson on November 27, 2014, 23:53
Greetings,

I would like to thank every one that answered my questions, so it seems to me that the Greenwich Coupling is the de facto standard because it works well. Trying to figure out how narrow gauge railways work in another country is one of the reasons that I have gone down this path. And I have really enjoyed the trips do far.

Thanks again for all of the good answers,
Andre Anderson
Portland Oregon USA
Title: Re: Greenwich Couplings
Post by: JulienW on November 28, 2014, 11:31
Quote from: B.Meldon on November 27, 2014, 09:58
I think the reasoning behind the Greenwich coupling was to produce a reasonable priced item than was more discrete than the Bemo couplings available and that could be uncoupled using hidden magnets, eliminating the need for very visible uncoupling ramps on layouts. (But please anyone do correct me if I am wrong!) The design is such that it is also partly compatible with the Bemo couplings, in that they will couple up, but as one type needs a ramp and the other a magnet automatic uncoupling between the two types is not possible. However as many H0e and 009 locos do not have the loops fitted these can work with the Greenwich couplings and the Egger/Bemo type. Also a hand held uncoupling tool can be used to uncouple both types.

If I may interject there Brian it should be possible to modify the Bemo couplings to work with magnets (not that I have tried).  I'll also point out that any coupling that will work magnetically can also be worked by electromagnets, which should avoid issues with things uncoupling when not required to do so and steel on the stock (axles and some wheel tyres) being attracted as can happen with permanent magnets.

Quote from: B.Meldon on November 27, 2014, 09:58
The main problem faced by all 009 modellers is that the coupling heights in kits and ready to run items are hardly ever the same so some adjustment of the couplings is often necessary to get them all at the same height. Failure to do this will result in unreliable coupling up, accidental uncoupling and not being able to uncouple remotely. Getting all the couplings adjusted correctly is key to success.

Brian Meldon


Agreed - the importance of getting the couplings all at the same height can not be over stressed. Greenwich supply an etched gauge, RT Models make a very useful resin item or one can make one from a bit of wood, a length of track and a screw (with a flat top) in the wood at one end of the track to set the coupling height.
Title: Re: Greenwich Couplings
Post by: Tigger on December 11, 2014, 08:10
The Greenwich coupling is an excellent design. I used it on all the Buccabury rolling stock (except the two cattle vans which use the larger Paul Windle couplings). It's ideal for the smaller wagons and perfect for the Dundas 'D' Type wagon bogies. I've never included the magnetic uncoupling facility but that's just me!

My own layout has always used a whole plethora of couplings but for scratchbuilt stock I've standardised on the Peco coupling. After the success of using them on Buccabury I started buying Greenwich ones with a view to converting my own stock - until I realised that the design of my wagon headstocks was matched to the Peco one and wouldn't allow the Greenwich to be fitted!

That said, I've used them on a number of kit-built wagons on me layout with great success.

The important thing is to standardise on one coupling type if you can and be very careful to set all the couplings to the same height. You can take that piece of advice from someone who didn't and hasn't respectively - and suffers the consequences!!!
Title: Re: Greenwich Couplings
Post by: berryr99 on December 11, 2014, 11:15
Well said.

Blaenau North stock will have Greenwich couplings as its standard.

Just about to start a large production run, now that I have sussed out how to make them - the You Tube video was a help, as was this forum.


Robert
Title: Re: Greenwich Couplings
Post by: Tigger on December 11, 2014, 12:09
Once you get going they're dead easy to build. I'm lucky in that one of the pairs of pliers I use is just the right size for bending both sides of the coupling to the correct width. It's important to get all the legs and pivot holes in line so it all works smoothly and squarely.
Title: Re: Greenwich Couplings
Post by: berryr99 on February 04, 2015, 16:20
Further progress. I have now built 40 couplings in one long production run.

The voices have now stopped and I have stopped trembling !

Please can someone recommend an adhesive to stick the couplings onto rolling stock. I was thinking of thick Superglue - Zap-a-Gap medium but would Araldite be a suitable glue ?

Thanks

Robert
Title: Re: Greenwich Couplings
Post by: Hugh Norwood on February 04, 2015, 20:35
I use the holes in the coupling shank and either brass wire or thread (or small BA screws) to hold them in place through holes in the floor of the rolling stock (or bogies)...
Title: Re: Greenwich Couplings
Post by: berryr99 on March 02, 2015, 19:18
I am fitting the couplings to rolling stock and getting the right height with very little problems at all.

However I have quite a number of Chris Ward 3d locos and the fitted coupling on those is too high for the stock.

At this stage the only solution I can see is to trim the coupling lug on the loco down a bit to reduce its height.

I was just wondering if there was a better way ?

Thanks

Robert
Title: Re: Greenwich Couplings
Post by: Frank on March 02, 2015, 19:47
I find the coupling mouldings on Chris's locos quite fragile and break quite quickly (possibly because I have a five year old grandson) so I usually cut them off and fit Greenwich couplings (without the loops) at the correct height.  They usually look better too as they are smaller.

I fit them by cutting a slot through the buffer beam at the correct height (drill a series of small holes then join them up with a craft knife or piercing saw) then shortening the shank slightly and fixing the shank in the slot with epoxy.

Frank
Title: Re: Greenwich Couplings
Post by: berryr99 on March 03, 2015, 09:33
Thank you Frank, this is what I will try.

Robert