Greenwich Couplings

[rhobat bryn]

I'm having to decide which coupling system to use and am currently considering the use of Greenwich couplings.  Having read various posts on the subject, it appears that views are mixed as to their advantages and disadvantages.  I would be particularly interested to hear from anyone who has successfully used an uncoupling system with Greenwich couplings or from anyone who has tried and run into difficulty.

[Darren Hedges]

See this topic http://www.009society.com/forum/index.php?topic=466.0

I have tried most couplings (with the exception of B&B) and I settled on the use of Greenwich couplings.

I retro fitted all my stock that gets shunted and I fit them to all new builds. I use an electromagnetic uncoupling system and the couplings work well with this.

The pro's for Greenwich couplings are-

Ready blackened
Large enough to work reliably but small enough to be discreet
Cheap (

[rhobat bryn]

Many thanks Darren.  I'm currently building some Parkside Dundas Tralee & Dingle Cattle Vans; I shall try them on those.

[Darren Hedges]

I would strongly suggest that you also use a Greenwich coupling height gauge, the last time I looked they cost just a pound.

This will enable you to fit your couplings at a consistant height, which will greatly improve the reliable operation of the couplings.

Darren.

[cp.409067]

See -

http://www.ngrm-online.com/forum/viewtopic.php?f=29&t=2893&p=43123&hilit=+Greenwich+Couplings+#p43123

Christopher Payne

[rhobat bryn]

Thanks Darren for the heads up on the coupling height gauge and also to Christopher for the referral to the ngrm forum.  Its clear that views on this subject vary according to personal taste but I think I've heard enough to give Greenwich couplings a try and see how it works out in practice.  When the time comes, I'll also be attempting an electromagnetic uncoupling sytem but that's a subject for another day.

[JulienW]

Some thoughts on Greenwich couplings:

I have heard of some people having problems when the heights are set very accurately as the loopes are etched.  This may sound odd but if you look at the cross section of an etch the cut is not vertical and, particularly if etched from both sides can be curved from top and bottom out towards a point or 'cusp'.  This kind of unevenness, or if the builder has filed the cusp away to give a flat face (which will make the problem worse), can make it very diffcult for the loop of one coupling to push over or under the loop of the other coupling to get to the hook.  This can apply to other types of coupling, but not where the coupling's loop is made of wire (like the DG system).  Having operated a layout with Greenwich couplings I did not expeience that problem, but the layout used fixed perminant magnets and I had problems with things uncoupling when I did not want them too (which is as much an issue of where they were put as that they can not be 'turned off' but also operator unfamiliarity) and unlike some of the 'kit built' couplings they do not have a delay function (i.e. uncoupled stock can be propelled into a siding and left) built in though this facility could be added by a fairly simple modification.

I may be biased as I use DG couplings myself after dabelling with Greenwich, BUT of the 'kit built' types they are probably one of the easier ones to build and are sturdier than some too.  Personally I would use them with electromagnets to avoid unwanted uncoupling and fit some sort of delayed action system to them (something to prevent a 'magnetically raised' loop dropping over the hook - like a wire sticking out horizontally from the end of the loco/ wagon / etc.).  The electromegnets will be more expensive then perminant magnets and also need extra wiering, but with a delayed action system the number of magnets needed is reduced (one per fan of sidings as opposed to one per siding) and once uncoupled stock can be pushed to wherever rather than trying to work out in advance where you'll need to uncouple (which could be multiple places on one long siding).

But whatever coupling system you use I would recomend having some sort of jig to set them up on so that they are at the correct height above the top of the rail and centerally mounted between the rails on evey bit of stock.  These can be quite complex affairs but my jig is a length of track mounted on a bit of 2" by 1" with a countersunk head screw fitted at one end between the rails.  The screw is not fully tightened so that the flat top of the screw's head is where the flat upper surface of the coupling needs to be - very useful for marking out cut-outs in buffer beams!

[B.Meldon]

Fixed magnets can also cause problems with locos and wagons getting stuck on the magnet.
One layout that I have operated had a few 4-6-0 locos that if stopped with the bogie pivot over the magnet would then not be able to move away as the magnet pulled down on the steel bogie screw and axels causing the driving wheels to slip on the spot!
I have also seen this same thing happen with wagons, especially light weight ones getting stuck on the magnets.

With the Greenwich coupling it is difficult to get electromagnets to work correctly, basically they are just not strong enough. One solution I have seen is to have uncoupling magnets that can be raised into position under the track, either using a simple mechanical lever system or a solenoid. This system would appear to give the best results, good uncoupling, no unwanted uncoupling and no weird magnetic effects on the locos or rolling stock. But it does take more work to set it up.

As others have said attention to detail when it comes to the height and positioning of any coupling is essential. Experimentation is also required as to the required movement on couplings on a given layout with vehicles that have large overhangs.

The actual stock you intend to use may also have an influence on what coupling you use. For example, if like me, you intend to use the Roco four wheel wagons either as they are or as bogies it is virtually imposable to change the couplings or the coupling height on these so having magnetic uncoupling will not work with these.

What I would recommend it to go to a specialist NG or 009 model railway exhibitions and have a look for layouts that employ regular shunting, see what couplings they are using and how effective they are.

Personally I use the so called Bemo couplings (actually first used by Egger-bahn.) and uncoupling ramps. I find that providing all the couplings are at the correct height and level they work very well. We get near 100% reliability.

Brian Meldon

[Darren Hedges]

With the Greenwich coupling it is difficult to get electromagnets to work correctly, basically they are just not strong enough.

I have not encounted any problems using electro-magnets with Greenwich couplers. My electro-magnet of choice is currently the one supllied by Guagemaster.

Darren.

[rhobat bryn]

Actually Darren, could you say a bit more about your use of electromagnets.  You've said you use the Gaugemaster version but where do you locate them on the track and how far beneath the baseboard are they?

[Darren Hedges]

The electromagnets are located between the rails with the steel rod cut off to just below top of sleeper level and when covered with a very thin layer of ballast are invisible.

I just drilled a hole through the baseboard for the rod (5 or 6 mm diameter I think) and the shortened steel rod is simply pushed through. The Gaugemaster electromagnets are mounted at 90 degrees onto a PCB that has a pre-drilled hole for mounting onto the underside of the baseboard with a suitable screw. You can use the 'push to make' switch included, or any switch that is biased to off.

An alternative to cutting the rod short would be to pack the magnet away from the baseboard with a few suitable sized pieces of thin plywood.



This image is linked from the Gaugemaster website at http://www.gaugemaster.com/item_details.asp?code=EM1&r=1

Hope this helps.

Darren.

[B.Meldon]

Hi Darren

It is good to know that this can be done, as I said I know of some who have had difficulties with electromagnets.

The Gaugemaster web site does not show a side view or give much in the way of details so:

What voltage do you use? (AC or DC?)

How long is the

[rhobat bryn]

Many thanks Darren, that's very helpful.  I shall refer back to it when I get to that stage in building the layout.

[Hugh Norwood]

Yup, I've gone over to using Greenwich couplings; once you get the knack of folding them up, they are a doddle. I agree that a bit of opening up of the holes makes the loop move easier (I use a 0.7mm drill)

I am also putting the iron wire on the loops, even though I do not yet have any magnets installed on Angst.

Another thing - put the loop on one end only of each item of rolling stock or loco.

[Darren Hedges]

Hi Darren

It is good to know that this can be done, as I said I know of some who have had difficulties with electromagnets.

The Gaugemaster web site does not show a side view or give much in the way of details so:

What voltage do you use? (AC or DC?)

It