Transport for LondonTechnology
Signalling is based on the SelTrac system, developed by Alcatel (Canada), which uses the latest 'moving block' technology.
SelTrac system
DLR trains are monitored by a central computer, which compares the position of each vehicle with a stored schedule.
This technology allows trains to travel closer together, permitting a more intensive train service without compromising safety.
The train's on-board computer constantly communicates with the central computer and, if this signal is broken, the train will stop until given the all clear to proceed.
Information is passed to the train to open its doors on the platform side, together with information to adjust speed in order to maintain the schedule.
Automatic Train Protection
All DLR trains are fitted with Automatic Train Protection (ATP), meaning trains run in their own safety zones, which no other train can enter.
ATP also regulates the maximum speed at which trains may operate. The highest speed on the railway is 80kmph (50mph).
Driving the trains
Passenger service agents can drive trains in a manual mode with the security of ATP. If the passenger service agent attempts to speed or depart when a route hasn't been set, the train will automatically brake.
If the signalling system fails, trains may be driven in 'emergency shunt' mode, which is limited to 20kmph. This may only be used when instructed by the controller, who gives authority for movement via the passenger service agent's radio.
The controller has an overview of the entire railway and controls all signalling and points. These can be operated 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 (eg when people are working trackside), decreased or increased braking (eg in wet weather).
Passengers entering and exiting DLR stations are counted by a fully automated infra-red counting system installed by Acorel.
