All boxes could communicate with adjacent boxes by their block telegraph. Signals were normally kept at 'all clear' but were set to 'danger' to protect trains as follows. When a train entered a block by passing a home signal, the signalman would set the home signal to 'danger', thus preventing a following train entering the same block. The distant would also be set to 'danger'. Trains were required to stop at a home signal at 'danger', but were allowed to pass a distant signal at 'danger' as this merely warned an approaching driver to moderate his speed to be ready to stop the train at the home signal. Both signals would be returned to 'all clear' when the next box telegraphed 'line clear'. Normally, as soon as a train was past a box's home signal, the signalman would telegraph 'line clear' to the preceding box. During foggy or snowy weather, however, when a train stopped at a station 'line clear' was not sent until the train had restarted, or been shunted into a siding. In good weather therefore a goods train being shunted into a siding at Abbots Ripton should have been protected against another train running into it by the Abbots Ripton 'home' and 'distant' signals ; in falling snow, the home and distant signals of the previous box should have given further protection and the fast train should always have been at least one full block away.