Replacements for LGB couplings

stockers said:
How does it work when pushing. I assume the plastic buffers will over lap and lock!
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Hi Alan
Now fitted my couplings and Binnie buffers to two LWB wagons and pleased to say there's no buffer lock, even when negotiating R1 reverse curves. Also pleased that, more by chance than careful design, the length of the hooks is also just right - short enough to give the impression of close coupling but long enough to allow the wagons to negotiate the curves without tightening-up. Not that LWB wagons will be travelling through R1 reverse curves on my railway.

Rik
 
Slowly progressing with replacing couplings with my version. However, I worked out that the buffers on the bogie coaches would have to be widened to cover 3/4 of the buffer beam if they needed to be propelled over my R2 (Trainline) crossover. I therefore decided to attach the buffers to the bogies as well as the hooks and loops.
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As can be seen, the buffers continue to be in contact with each other through the crossover.
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Not sure if there is a precedent for this on narrow gauge railways. Be interested if anyone knows how the couplings on bogie stock are made to negotiate tight reverse curves on the real thing.

Rik
 
I know only 2 strategies on the real thing:
1) Avoid S-shaped curves and provide a straight section between curves with the minimum length of the longest vehicle. If this is not possible (e.g. sidings in stations), special rules apply - push trains extremely slowly, escorted by an shunter who controls if the buffers start to overlap.
2) Provide wide buffers. Please compare the buffer size between the Mansfeld-750mm loco and the main line class 44:
1533467138567.png
The grease distribution on the NG buffer indicates how much the buffer movement can go. Note also the cutouts left and right to provide more freedom for the couplings.

Same principle with the cutouts on the HSB. The long coaches have their couplings mounted on the bogies:

1533467436264.png

If the coupling is mounted below the buffer (e.g. Brohltalbahn) , not cutouts are necessary and the buffer can be as wide as necessary. Note also here the grease distribution on a short 2-axle goods van.
1533467723364.png

Andreas

EDIT: Sorry when I was at the Brohltalbahn I did not make any pics from 4 axle bogies...
Please refer to this link - Bilder von der Brohltalbahn vom 05.06.07 - Eisenbahnforum der Region Mittelrhein
The 3rd pic from the top shows a long bogie coach purchased from the Berner Oberland Bahn. The original buffers were replaced with mainline coach buffers, body mounted, wide surface to avoid overlapping.
 
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65 1057 said:
I know only 2 strategies on the real thing:
1) Avoid S-shaped curves and provide a straight section between curves with the minimum length of the longest vehicle. If this is not possible (e.g. sidings in stations), special rules apply - push trains extremely slowly, escorted by an shunter who controls if the buffers start to overlap.
2) Provide wide buffers. Please compare the buffer size between the Mansfeld-750mm loco and the main line class 44:
View attachment 241469
The grease distribution on the NG buffer indicates how much the buffer movement can go. Note also the cutouts left and right to provide more freedom for the couplings.

Same principle with the cutouts on the HSB. The long coaches have their couplings mounted on the bogies:

View attachment 241470

If the coupling is mounted below the buffer (e.g. Brohltalbahn) , not cutouts are necessary and the buffer can be as wide as necessary. Note also here the grease distribution on a short 2-axle goods van.
View attachment 241471

Andreas

EDIT: Sorry when I was at the Brohltalbahn I did not make any pics from 4 axle bogies...
Please refer to this link - Bilder von der Brohltalbahn vom 05.06.07 - Eisenbahnforum der Region Mittelrhein
The 3rd pic from the top shows a long bogie coach purchased from the Berner Oberland Bahn. The original buffers were replaced with mainline coach buffers, body mounted, wide surface to avoid overlapping.
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That's great Andreas, thanks. Plenty of really useful information here. Really interesting that the buffing plates on the coaches are much larger than on the locos.

Rik
 
Well, after a bit of head-scratching and some experimentation, I have achieved my objective of creating a hook-and-loop coupling with delayed action uncoupling. However, I'm not sure how practicable it is (more later).

The loops are as before but the hook has been modified to include a forwards facing larger hook behind the normal hook. I'll call this the "delay latch".
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The coupling hooks couple-up in the usual way. Push one or both wagons together ......
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... and the hooks latch on to the loops and away we go.
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To uncouple, the wagons are propelled backwards (or one is propelled backwards and the other is stationary).
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The couplings are then pushed downwards to disengage the hooks from the loops. At the same time, the 'delay latches' on the hooks force the wagons apart slightly as they meet the loop on the other wagon.
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The uncoupler is removed and the wagons continue to be propelled backwards. The delay latches are now the other side of the loops on the opposite wagons.
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When the wagons are pulled apart (or one is stationary and the other is pulled away from it), the delay latches slide under the loops, .......
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...... preventing the coupling hooks re-engaging with the loops.
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Thus the wagons are uncoupled when they are pulled apart at any point after they have been uncoupled.
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I have tried using magnets to do the uncoupling by soldering steel droppers to the underside of the hooks. However, I've not found magnets which are sufficiently strong to pull the hooks down and keep them held down while the delay latches come into force. I might need longer magnets.

Whilst all this is fine in theory, in reality, it's tricky getting the delay latches to work reliably. If the wagon being uncoupled is too light when the hooks are depressed the wagon springs away under the pressure from the delay latches and then when the propelling is continued the coupling hooks re-engage. If the wagon to be uncoupled is too heavy (eg if there are several other wagons behind it), then it's difficult to push the hooks down as the delay latches have to force the wagons apart slightly to work.

So theoretically, the delay latches are a workable concept - but in practice they are not really viable. If I could get the delay latches to hinge upwards somehow and then drop down again to cover the hook then it would work - but it will make the hooks too complicated to construct and might end up interfering with the coupling and uncoupling process.

So - I'll stick with the status quo - ie uncoupling wagons at each location where I want them to remain.

Rik
 
Just a thought while you are in experimental mode as it were. If the delay latches were a solder fit rather than bent this would make the dropper arm a litle less complext to bend and it would be quite possible to adjust better as well. Plus if it were below the loop as well a little with a piece of tinplate soldered to the bottom you may get a little more reliability from the magnets when uncoupling. Rare earth Magnets can be so much stronger for your purposes. Not entirely sure what magnets you have been trying.
 
Hi Jon and David
I've decided to abandon the idea of delayed uncoupling - quite apart from the reliability issues, on reflection I'd have to use an electromagnet or be able to raise and lower the magnet to only uncouple the wagons which need uncoupling. So, I'm going to stick with the status quo and just position permanent magnets at strategic places in the sidings and loops. Tension will keep the hooks coupled when pulling and I'll just position the stock which needs uncoupling over the magnets and reverse - just as I do with my indoor 00 railway and tension-lock couplings. Yes, rare earth magnets are the way to go.

Thanks for the reminder about your couplings, David. I like the idea of the steel 'chain' - much better than droppers - both practically and aesthetically. I see you've made your own chains, but I think some 16 millers use steel 3 link chains as I believe some of them use magnets to lift them off the hooks.

A bit more experimentation I think.

Rik
 
Just re-read your article, David. I hadn't realised your hooks included a delay feature. So, to activate the delay, you just pause the coupling over the magnet, otherwise you can keep propelling and the hooks remain engaged??

For reliability (and also because I have a reverse loop on my railway), I have hooks at both ends of each wagon. Does your system work equally well with two hooks?

Rik
 
ge_rik said:
Just re-read your article, David. I hadn't realised your hooks included a delay feature. So, to activate the delay, you just pause the coupling over the magnet, otherwise you can keep propelling and the hooks remain engaged??

For reliability (and also because I have a reverse loop on my railway), I have hooks at both ends of each wagon. Does your system work equally well with two hooks?

Rik
Click to expand...

Rik

I came up with the idea for use on an indoor shunting layout. I included the caveat at the end of the article that I doubt it would stand up to the rigours of undulating outdoor track. I have never tried it 'double hooked' as it was never a requirement of mine. My requirement was to modify individual goods wagons so as to be able to shunt them on a level indoor layout without using 'the hand of God'. Passenger vehicles will be run as fixed rakes, with coaches coupled together with unmodified LGB couplings, either single or double hooked as the mood takes you, with only the couplings at each end of the rake modified to facilitate hands free running around of the loco. The chain droppers are actually made from the soft iron wire supplied with the S&W brass frets. The wire for the coupling loops, also supplied, is much tougher stuff, probably nickel silver.

dig 150524005.JPG

David
 
Been doing some experimenting and the magnets (even neodymium ones) aren't strong enough to pull down the hooks - the phosphor bronze wire is too springy. I might be able to do it if I angle the magnets downwards, so the chains are attracted and then slowly pulled down as the wagon moves along the length of the magnet.

The hinges on your couplings look more effective from that perspective. Am I right in assuming that the weight of the other half of the hook is sufficient to return the hook upwards? There can't be much difference in the weighting of the two halves (unless the brass is doubled-over).

Might have to try some more experiments!!! Not sure how a similar system would stand up to the rigours of the garden environment - might have to over-engineer it somehow.

Rik
 
Rik

Yes the counterweight design of the brass hook is sufficient to return the hook to the horizontal under its own weight. You have to realise that Spratt & Winkle couplings are tried and tested and have been around for years in the smaller scales, used by hundreds, if not thousands' of modellers. All the design and trial work was carried out years ago and all the components work as they are supposed to. Everything required is supplied as a kit or can be purchased separately. All I have done is experiment with using the largest version, 'O' gauge (7mm scale) by applying it to G Scale.

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David
 
Hi David
I wasn't questioning their design, just seeking clarification. They must be finely balanced and therefore require minimal magnetic attraction to draw them down, which is the problem I am experiencing. I'm just trying to figure out if it's worth the extra effort required to make pivots for my couplings or whether to rely solely on the springiness of the phosphor bronze. One solution is to use finer gauge PB wire, but then they would be more susceptible to accidental damage. I think I may have to accept that my couplings will not be able to be uncoupled with magnets.

Rik
 
I used Sprats years ago in 00, well before the delay feature was available and they worked very well indeed. My suggestiins a little earlier were based in Sprats Concepts so you will be able to make the comparison here with what David has been using. A small piece of wire to replicate the delay function coupled with Steel Chain may still give your delay requirements. You are so very close to utopia Rik just a little more experimenting!
 
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