Dingham couplings- user experience 00 gauge

[Junctionmad]

I'm experimenting with these couplings, diesel era layout , lots of bogie stock. I notice many f the threads are a few years old.

 

How have people faired with Dinghsms, minimum radius issues , crossovers, reverse curves etc , what about bogies stock and handling loco run round issues with handed couplings

 

Any experiences ?

[Edmund Kinder]

I'm experimenting with these couplings, diesel era layout , lots of bogie stock. I notice many f the threads are a few years old.

 

How have people faired with Dinghsms, minimum radius issues , crossovers, reverse curves etc , what about bogies stock and handling loco run round issues with handed couplings

 

Any experiences ?

Hi

 

I've been using Dingham couplings for many years on my 4mm layout for some of my stock and they have been mostly successful.  The experiences I've had are listed below:

 

1. They can be quite fiddly to make as they're quite small and require soldering, but with practice you can get the hang of construction.
2. It is absolutely imperative to get the height absolutely correct on all wagons so that the couplings match because the tolerance is so small.
3. For shunting purposes, they rely on the buffers of the rolling stock being non-sprung so a gap is maintained when propelling,  Having sprung buffers will cause them not to uncouple. This means I've had to glue some of my locomotive spring buffers solid!
4. With the couplings having a hook on one end and a loop on the other, using a turntable to turn a loco would create problems hook to hook or loop to loop.  I imagine with a diesel era layout, you won't be turning engines.  I tend to run my coaching stock in sets and have loops at each and of the set and only have hooks on both ends of the loco to address this challenge.
5. When they work and uncouple using an electromagnet, they are very impressive and visitors have said things like "wow, how did you do that"
6. Because they're quite discrete (which is the whole point of course), when you are uncoupling whilst propelling stock, you can't often see clearly if the uncoupling has been successful until you draw away the rest of the wagons and things are still coupled - this raises eyebrows amongst visitors.  
7. Minimum radius curves I have are 4 to 5 feet on the scenic section, but I imagine they'd work on 3 feet at a push. 

 I have a selection of wagons and coaches using Dingham couplings whilst I have rakes of wagons that use 3-link so are always coupled.  I also still have a huge amount of rtr couplings to convert.  I did find a layout at ExpoEM once also using Dinghams successfully and they told me that they too have a selection of rolling stock fitted and not all so they can "chop up" rakes whilst shunting.

 

Hope that helps -any more specific questions let me know.

 

Edmund

[micklner]

Couldn't get them around bends on coaches and bogie wagons and sold them on.

[Ray H]

I have a vague recollection of reading one thread on here where the minimum radius that they'd successfully work was reported to be 2ft. I don't remember whether this was for propelling or shunting - from my (very) limited experience of their 7mm cousins I can't think that there would be any problem when being pulled around such a curve unless doing so relied on sprung buffers (which goes against Edmund's experience above).

[SR DUNCAN]

Hi  I agree with everything Edmund has said but I wish to add a few comments.  On the carriages I fitted the latch coupling to either end of the rake of carriages and then fitted the loop end to the tender or back of the locos that would be pulling carriages only.  The advantage of this is that these locos can be reversed and pull the carriages in either direction.  The couplings on the carriages need to be fitted to the boggie rather than to the carriage bodies to cope with going round bends and cross-over point work.  Goods locos either loop or latch could be fitted to the back or tender but this would determine which way the loco would run around your layout.  As my layout is basically steam period I am only using 4 wheel wagons.  One electro magnet placed at the entrance to your goods yard which needs to be on a straight section of track enables you to "shunt on the fly" and you can then drop the wagons wherever you wish to - very realistic and impressive.  They are well worth the effort and require a little thinking about before you start fitting.

[Junctionmad]

Thanks for that. Any comparisons with S& W couplings.

 

The comments re needing to fit to the bogies is a pity as the whole idea was a buffer beam install

[BG John]

This seems to suggest they will work on coaches attached to the buffer beam. Maybe it depends on the type of layout and stock used.

http://yourmodelrailway.net/view_topic.php?id=2220&forum_id=11&highlight=dingham+couplings

[micklner]

See post 3 . On reading the link he hasn't said what bends the coaches go around mine are 2' 6" and they locked on bends as there is zero flexibility in the design, no better than 4mm scale screw couplings/3 links which I only use on wagons as per that link as well.

[34theletterbetweenB&D]

...The comments re needing to fit to the bogies is a pity as the whole idea was a buffer beam install

Perfectly successful on vehicle ends, but there is a minimum radius requirement. Needs a 36" minimum radius on plain track in my opinion to work reliably with 60' bogie vehicles like a mk1 coach, reverse curves formed by point crossovers ideally large, think 48" minimum. I did not test this exhaustively as I had decided at that stage that they were a 'close but no cigar' solution to a better autocoupling that looks and functions at least somewhat like three link and screw link.

 

Thanks to the kindness of another member here I have been introduced to the French 'JC' coupling design, which looks the very business. The coupling link has more freedom to pivot on the hook which removes the lateral constraint that the Dingham design applies in the reverse curve situation. See this thread entry:

 

There is (or possibly was) such a coupler called the J.C. after its inventor. He does though seem to have remained anonymous, probably because he was seeking to commercialise it though as far as I can tell that never happened.

 

The coupler was described in great detail in three articles in Loco-Revue in the final quarter of 1977 and it was certainly ingenious.

 

Basically a loop, which could be in the form of a screwlink coupler (or presumably a three link) hung from the drawbar of one vehicle. On the other vehicle a downward facing hook that was strongly magnetised (possibly wiith the help of a permanent magnet mounted behind the buffer beam)  protruded from its drawbar. The hook was sufficiently magnetised that, when another vehicle approached it,  its loop, which was made of iron or steel, would be sufficienty attracted to swing up and engage with the hook. The magnetic force would then hold it in position. The hook only pulled and the buffers were needed for propelling movements.

 

The ingenious part was the uncoupling. When the loop was raised an iron or steel bar or wire hung downwards. The uncoupling device was an electromagnet with the opposite polarity when energised as the hook. This neutralised the magnetic force holding the loop in place and it would fall away under gravity. Presumably the train had to be pulled clear before the electromagnet was de-energised or else the loop would simply swing back up.  The parts of the coupler not required to be magnetic were made of brass.

 

The whole thing seems fiendishly complicated but apparently it worked very well and in some online discussion about it a few years ago several modellers said that they'd used the J.C. coupler system succesfully for many years and one said it was easier to build and fit than Alex Jacksons (with which French fine scale modellers are very familiar)   It did though have several disadvantages.

1. It was single ended, there was only one hook and one loop though J.C. reportedly came up with a double ended version.

2. It relied on buffers to do the pushing. Avoiding  buffer locking imposed quite large minimum radii  but no more than for manual 3- link or screw couplers. The third article went into enormous detail about the calculation of buffer displacement on curves)

3. Unlike the Kadee and some other magnetic systems, uncoupling could only happen over the electromagnet.

4. The contruction probably was more complicated than for Alex Jacksons

 

The big advantage was that it could be made to look like a real screwlink coupling.

 

The articles are still copyright but you'll find a discussion here

http://forum.e-train.fr/viewtopic.php?f=2&t=13687&hilit=attelages+JC

 

and a diagram of the basic construction here

http://forum.e-train.fr/album_mod/upload/db07a6693d104241c93acc9d2a9d0cef.jpg

 

It might give someone ideas.

[Junctionmad]

It sounds like sprat & wrinkle might be a better compromise as the bar is a lot wider