Mission Impossible?

[David Holman]

For those of you who like such things, here is a shunting puzzle I have been trying to solve, but without success. Most trains on Belmullet can be operated with Dingham auto couplings and just three strategically placed magnets. Dinghams are 'handed' though, which doesn't work well when both whole trains and locos are turned at each end. However, by having hooks on the locos and loops on the end of the first and last wagon/coach of each train, not only is basic running round achievable 'hands free' but two trains can swap wagons as can a rake of wagons in the goods shed be exchanged with an incoming set. 

 The difficulty arrives with two trains [one for each period modelled], where I want to swap a single wagon from a 'mixed' train with one from either the the bay or end loading dock. At the moment, these trains have either screw or three link couplings, which need to be worked by hand. My question is, could the sequence be done using Dinghams and the magnets?

 Each train is made up of the locomotive [which will be turned on the turntable], one or two passenger vehicles, a couple of wagons and a brake van bringing up the rear. On arriving in the platform, the loco needs to uncouple and be turned on the turntable. Afterwards, the brake van needs to go to the other end of the train and one of the wagons swapped with one from the bay/loading dock. On return to the fiddle yard, the whole train is turned for the next outing.

 Note that Dinghams have to be either a hook or loop - you cannot have a hook and loop on both vehicles coupling up as they don't work reliably. Everything I've tried thus far ends up with a mismatch when the whole train is turned and returns the next time. Indeed, am not sure anything IS possible, though one thing that might help is that a pilot loco can be available, though note that locos can only be isolated in the loco shed area, either side of the turntable [ie room for three locos].

 A schematic is shown below and additional magnets could be added. No prizes for success, but you would have my eternal gratitude! 

 This message will self destruct in 15 seconds...

[J-Mo Arts]

It would take the fun out of a shunting puzzle, but for a bit of interesting operation at an exhibition, what if the wagon to be removed had these magnetic couplings inside the rake while the rest of the rake had 3-links, with the exception of the adjacent two 'translator' wagons? That way your wagon could be removed and shunted off, and the train reformed. 

 

 

Please excuse the crudity of my sketch. Red represents one 'hand' of your magnetic couplings and the D shape represents the other. This would give you a predetermined wagon to shunt, and might be a workable solution. You could push the train to the station, uncouple the brake van and end wagons, navigate the remaining wagons to the goods shed, drop off the magnetic-coupled wagon, then pick up the spare wagon from the loading dock and return to couple the train together in the platform. Probably not the most realistic operation (maybe excusable on a quiet day with a long gap between services) but perhaps one solution. Hope this helps

On 20/9/2021 at 10:02 PM, David Holman said:

 No prizes for success, but you would have my eternal gratitude!