The construction of Grey Havens station saw the introduction of safety-related electrical systems. The station is linked to the rest of the railway via a 'bridge' that drops down when not in use which potentially allows trains to run off the end of the track and over the edge of the baseboard. To solve this problem microswitches have been installed that permit power to reach the track only when it is safe to move a train. This is when either the bridge is impassable and a barrier across the track is closed or when the bridge is in place and the barrier is open. No other combination will allow power to reach the track. More information and a photograph can be found Here.