RULES & OPERATION
The object of the Inglenook Sidings shunting puzzle is fairly simple, the order for the shunting crew being:
"Form a departing train consisting of 5 out of the 8 wagons sitting in the sidings."
In addition (and this is where the "game element" of the puzzle comes in) the shunting order states:
"The 5 wagons are selected at random."
On the original Inglenook Sidings, Alan Wright employed what he called the "Tiddlywink Computer" for this task, i.e. distinct tokens for each wagon drawn from a mug. No matter how these 5 items of rolling stock are determined, the order in which this happens is important because:
"The train must be made up of the 5 wagons in the order in which they are selected."
An example of what this can look like is given below, illustrating that despite its simplicity, this shunting puzzle can produce some combinations which require a certain amount of thinking and a number of moves:
The challenge of fulfilling this shunting order is linked to the fact that some advance thinking is required due to the fact that there is limited space available to juggle around the rolling stock, as determined by the lengths of the individual sidings and the headshunt.
What looks like a simple task can provoke quite a bit of headscratching. The number of possible combinations regarding the positions of these 8 items of rolling stock, by the way, is a mere 40'320, so it should take some time before a feeling of "oh yes, I know this one" grabs the operator. Once the train is made up, the five items of rolling stock are either simply redistributed on the sidings wherever there is room for them, or replaced with five other items if the headshunt leads to somewhere, e.g. a fiddleyard or perhaps even a larger layout.
You can get a first-hand impression of what it's like to operate an "Inglenook Sidings" layout straight away, thanks to Neil Machin's virtual "Inglenook Sidings" shunting puzzle.
If you already have a working Inglenook layout, you will find that the Inglenook Random Wagon Selector, a sleek piece of software (runs on Windows PCs), allows you to leave the shuffling of whatever kind of tokens you use to the computer. The screenshot below shows an example list of cars on the layout and how the Selector produces a random list of cars in the order in which they are to be shunted.
This software is (c) William Pearson and now available in an upgraded version which also allows you to save your source data. You can get it here as a downloadable zip-file (with kind permission and courtesy of Mark Kendrick).
Hints for Inglenook Sidings solution strategies
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Page created: 01/MAY/2001