The Wood Shed was a wooden building located next to the engine shed and sawmill. It was used to store cut wood from the sawmill but also to dry out wood prior to them being cut. During this time it was also used to store many of the wooden fence posts that were cut and to creosote them prior to fixing them in the ground.
The building was demolished in that late 1990s and the only image that remains is the one below. It give a rough idea what the shed was like. It is the building in middle right of image below next to the trees