He approached Arriving with excess speed and braked Self_motion too late .

On receiving a train approaching signal notifying him of the approaching the express , he realised Know his mistake , but he was only able to alert the freight train by red flag and although it braked Self_motion to a halt , it could not be cleared from the up main line in time to avoid the collision .

The rear portion was inadequately braked Hold and ran Self_motion back down the gradient , colliding Motion with a following train .