Ground Level and Raised tracks are independent of each other. Signalling for the raised track is the smaller of the two signalling projects, there will be no connection between the two, but the technology used is common.
The Raised track will be workable in either direction.
First to be constructed is the 'small loop', later an outer 'large' loop will be completed. Part of the track is common, which option being selected using two 'traversers'. These are the only significant obstacles on the raised track, there are no gates or crossings.
The Steaming Bay traverser will be locked into one of three positions to enable :
When using the Large Loop only two positions are required, as the steaming bay line connects to the traverser section forming part of the large loop.
When using the small Loop a slightly more complicated set of actions is needed. To bring a loco onto the track, the traverser is positioned to enable transfer from steaming bay line onto traverser. The traverser is moved to align the steaming bay end of occupied traverser track with the common line. Loco or stock then reverses onto the common track. Finally, traverser is moved to insert the Small Loop section completing the Small Loop.