Shunting Puzzle

I've been working on the trackplan for the next Farthing layout, which will show part of a large GWR goods depot.

In order to improve the operating interest, I've decided to incorporate a shunting puzzle in the track plan. For anyone interested in shunting puzzles, I can recommend the excellent Model Railway Shunting Puzzles site, plus of course Carl Arendt's site. The simple plan above (not to scale) is an initial design, and may be revised. Any ideas for improvement would be very much appreciated. I'll explain the visual side of things in a separate blog entry.

The trackplan is similar to the famous "Inglenook" design, but the objective of operation is different: In the Inglenook concept, the aim is to assemble a goods train for departure. Here the aim is to distribute wagons from a reception siding by moving them into the goods depot in a particular order, while at the same time removing empty stock from within the depot.

This was inspired by the practice at larger goods depots on the GWR (and I expect elsewhere), where incoming vans and wagons were met by a superintendent in the reception roads outside the depot, who then assigned them to particular sections of platforms (or "decks" as they were called) inside the depot.

The diagram above shows an example of the challenge. This is the basic procedure:

  • Prepare the puzzle by arranging the wagons as illustrated, ie with five inbound wagons in the reception road, and five outbound (ie empty) wagons in random locations inside the depot.
  • Allocate each of the inbound wagons to a particular location on the two tracks within the goods depot. This is done by eg drawing the wagon numbers out of a hat.
  • Shunt the incoming wagons to their respective destinations within the depot, while also removing empty wagons from the shed. The reception siding may be used to set down wagons temporarily during the shunting. The challenge is completed when all the incoming wagons are in their predefined location, and the outgoing/empty wagons are in the headshunt (any order).

The puzzle has two difficulty levels: In Simple mode, any maneuver is allowed. In Advanced mode, two rules apply:

  • The loco is not allowed to enter the depot (as was often the case in reality due to the fire hazard). A wagon that is destined for the far end of a platform inside the depot must therefore be propelled using other intermediate wagons.
  • Wagons must not be left temporarily inside the depot during shunting operations, only outside.