Between panel 1 and panel 2 there are a number of crossovers allowing trains to pass between the Main lines and the Windsor lines. Each of these crossovers requires two or more "part routes" to be set, one (or more) on the Main side and one (or more) on the Windsor side. The route on the origin side needs to be set to the grey exit triangle in the usual way. Note that the points between the Main and Windsor side will not show locked at this juncture. Next the signaller on the receiving side needs to set a route from the red entrance triangle to the appropriate exit signal. Once both sides are locked, the points between the Main and Windsor side will call and lock.
The red entrance arrow will turn to white once a route has been set.
If the route has not been used, route cancellation takes place in the usual way at the entrance signal, but also needs to be pulled from the red entrance triangle too.
There are some routes that can go from Main to Windsor to Main, thus involving three part routes. The first and last routes are set in the same way as above. The middle route is set from the red entrance triangle to the grey exit triangle.
Note that it is possible for a part route to be set which looks like it conflicts with something on the other side of the boundary. However, as the points over the boundary are not yet called, it is perfectly possible for trains to pass by without risk - and allows the other signaller to continue undisturbed until he/she is ready to take the train crossing over the boundary.
Last edited by GeoffM on 15/09/2016 at 03:00