Where there is a high risk of a train passing a red signal and causing an accident, double red protection has been put in place. This is where the signal preceding the one protecting the high risk area is held at red until an approaching train has sufficiently slowed, or the high risk protecting signal has a route set from it. The route does not need to have all tracks clear or possibly other controls satisfied, but does need all points in the route called and detected to the appropriate position. This latter requirement, of pointwork detected, was introduced shortly after the initial trials and so SimSig always requires the points controlled and detected.
Last edited by GeoffM on 15/09/2016 at 03:00