The high and low yards are in fact just the fiddle yards used on the modules. They are both the same. they are Grainge & Hodder traverser boards. Each has three tracks for trains and two storage tracks
Each track is aligned to the departure track with brass bolts. These provide the power to the tracks as well as the alignment.
Both ends of the board have guard rails to stop the stock falling off when the board is turned 180 degrees. These are raised at the connected end and act as a buffer stop at the open end