Transport for LondonTechnology
Signalling & Control
The railway utilises a fully automatic train control (ATC) system, which is monitored by the permanently staffed Control Centre located at Poplar. The signalling system is based on the Seltrac system, developed by Alcatel (Canada) using the latest technology, "moving block system." It allows trains to travel closer together and so permits a more intensive train service to be operated, yet still in complete safety.
Trains are constantly monitored by the central computer, which compares the position of each vehicle with a stored schedule. The train's on-board computer constantly communicates with the central computer and if this signal is broken the train will stop until given further authorisation to continue. Information is passed to the train to open its doors on the platform side together with the required information to continue with adjustments in speed to maintain the schedule.
All trains are fitted with Automatic Train Protection (ATP). ATP means that the train runs in its own safety zone which no other train can enter. It also regulates the maximum speed that the train may operate on any section of the track. The highest speed on the railway is 80 kph (50 mph).
The Passenger Service Agent can drive trains in a manual mode with all the protection of Automatic Train Protection. If the Passenger Service Agent attempts to over speed or depart when a route has not been set, the train will automatically apply the emergency brakes preventing further movement.
If the signalling system fails completely trains may be driven in Emergency Shunt mode which is limited to 20kph. This may only be used when instructed by the Controller who gives authority for movement via the Passenger Service Agents radio.
The Controller has a complete overview of the entire railway and control of all the signalling and points, which he/she can operate via the System Management Centre computer.
The Controller can also send commands to the Vehicle On Board Computer (located on every train) by inputting commands on the Vehicle Control Centre such as reduced speed, go slow zones (e.g. persons working track side), decreased/increased braking (e.g. in wet weather conditions).
Passengers entering and exiting DLR stations are counted by a fully automated infra-red counting system installed by Acorel.
