Almost all trains in this country use a compressed-air braking system which is designed so that, if a train should divide, the brakes will be put hard on, in both bits. That will happen automatically when the brake hoses are pulled apart.
But if "Networker" trains come uncoupled, that does not happen. The automatic couplers used between the two- or four-coach units have self-sealing connections.
As recent events have shown, if this happens the front part carries on with the driver unaware of what has happened. But what happens to the back part?
The severance of the control circuits will ensure that its traction power is cut off, but do the brakes come on? Or does it just roll on, driverless and brakeless?
And if the front part is stopped, what is there to prevent the back part from crashing into it?
Dr ARTHUR TARRANT