Shunter Couplings

[michael.hamilton]

I have recently acquired, from different sources, two NSWR 0-6-0 shunters dating from the 1970s (model number R.165). I am puzzled by the rear couplings. They have a raised plastic section on the left side that prevents the coupling hook from a wagon connecting to the loco. The coupling hook from the loco (on the right side) operates as normal. I would appreciate any information on the reason for this design.

[walkingthedog]

Can you post a picture, sounds a bit odd. 

[michael.hamilton]

I'll have a go at posting a picture.

[michael.hamilton]

/media/tinymce_upload/cac8e4b090a4f98796331f4a5ecab2b5.jpg

[dynax]

i had a shunter like that, it was for auto uncoupling, if you reverse the shunter with a bit of a jerky movement the coupling hook will lift up and the shunter can be driven away leaving the wagon or coach where it is,

[michael.hamilton]

Thanks, Mike. I'll have a play with it tomorrow.

[Ruffnut Thorston]

I have recently acquired, from different sources, two NSWR 0-6-0 shunters dating from the 1970s (model number R.165). I am puzzled by the rear couplings. They have a raised plastic section on the left side that prevents the coupling hook from a wagon connecting to the loco. The coupling hook from the loco (on the right side) operates as normal. I would appreciate any information on the reason for this design.

It is for the "automatic uncoupling" feature...

Inside the cab, the rear coupling hook is mounted on a pivot that is alsongside a longer "arm" with a weight at the top.

If the loco is moving forward with a wagon coupled behind it, and then stopped suddenly, the weight moves forward (Newton's law) and so lifts the coupling hook on the loco upwards.

When the loco moves forward again, the sloped "lump" in the loco coupling allows the wagon coupling hook to slip out, leaving the wagon uncoupled.

To get the loco hook back down, to couple to something, the loco needs to move backwards, and stop suddenly.

This feature was going to be put on more models, but it didn't catch on!

BR 08 models with the chassis based on the B12 chassis block were fittted with this device. The NSWR (Australian) type is the same loco in a different livery....

 

[LCDR]

  Has Hornby ever contemplated a DCC operated remote uncoupler for the later shunters ?

[michael.hamilton]

Thank, Sarah, for your explanation. I've had a look inside the cabs and I can see the pivots and weights. I might try lubricating them, as they don't seem to be moving very freely, and the coupling/uncoupling action is not very reliable, even with sudden stops.

 

[michael.hamilton]

I also agree that a DCC uncoupling mechanism would be an excellent idea.