This one was tricky!
Thomas, Mark, Lauran, Kay and Shoaib from the Tithe Barn Primary School worked hard on it. Sometimes it helps to work together. Their teacher says:
This was difficult, but totally absorbing. Working individually with pencil and paper little progress was being made. We started thinking as a group and decided to make a model of the problem. A red card was used to represent the cattle truck, a blue one for the sheep truck, a white one for the engine and an inverted 'V' shape piece of paper for the footbridge. A ruler was used for the main line and a circle drawn in pencil served as the railway siding.
On more than one occasion we thought we had solved the problem, but were unable to reproduce the result. The engine moves were recorded and after many attempts and much excitement we achieved it.
Here are the Shunting Instructions they came up with.
The trucks have changed places!
Josh (from Ampthill, Bedfordshire) also gave an excellent description of the solution:
The engine reverses on to the loop, then goes forward and connects to the sheep truck. It reverses and pulls this clockwise round the loop and then pushes it forward on to the main line. It reverses back on the loop then goes anti-clockwise round under the bridge and pushes the cattle truck on to the main line next to the sheep truck. Then it reverses and pulls both trucks back on the loop. Then it goes anti-clockwise and pushes the sheep truck back where it came from. Then it reverses pulling the cattle truck clockwise. Then it stops, goes forward and shunts the cattle truck on to the mainline. Then the engine reverses on its own back on to the loop, goes round clockwise under the bridge and carries on pushing the sheep truck round to where the cattle truck started off. Then the engine reverses and goes back on to the main line to get the cattle truck. It pulls the cattle truck back on to the loop, then changes direction and pushes it anti-clockwise to where the sheep truck was. Finally the engine reverses and then goes forward again on to the main line.