An extension to Beckton Depot, situated on the Docklands Light Railway in East London, was constructed and Balfour Beatty Rail Signalling (BBRS) was contracted by Docklands Light Railway through Mowlems, the main contractor for the depot expansion, to undertake the signalling and telecommunications element of the scheme.

The extension to the depot consisted of four berthing/through tracks, each equipped to detect three three-car unit trains, signalling similar to the existing depot. The construction of the depot extension interfaced directly with the existing Beckton Depot tracks at the East End and to the main line signalling, which is an Alcatel “Seltrac” moving block system, at the West End.

The road access to the depot crossed the single line connection to the existing depot at the East End. Level crossing protection equipment was provided and controlled from the security gatehouse by a panel, and interlocked with the signalling equipment.

The provision of a new PLC-based signalling interlocking for the depot extension allowed normal operation from the existing depot control console in the Poplar Control Room. This also allowed the extension to be operated from the standby control panel at Beckton Depot in the event of communication problems.

The existing depot control interface at Poplar, which consisted of a simulated NX (entrance/exit) panel on a PC linked by modem to the interlocking PLC at Beckton, was modified to include the extension, with the existing control panel at Beckton being replaced. All points were trailable for light rail vehicles and operated by a hydraulic power pack.

They were also capable of being isolated, operated by crank or lever, and indicated on the control panel. The signals installed were all short range two-aspect signals to match those already in use in the existing depot. The twelve track circuits used were all single rail to enable a continuous traction return for the 750V DC traction supply system, with the traction return rail adjacent to the conductor rail to maintain use of the short circuiting device.

The new signalling equipment was housed within five new standard location cases and two new REB’s. The design was carried out to the standards laid down within the Docklands Light Railway Engineering Design Manual, with the level crossing requiring approval from both DLR and HM Railway Inspectorate.

The level crossing equipment consisted of two level crossing hydraulic barriers incorporating LED boom lights, four flashing roadlights on pre-cast concrete bases, and yodalarms, together with associated rail surface; fencing; white lining and signage. Although a Ground Plan was produced, a crossing order was not required as the crossing was located on a private

PROJECT STATISTICS
Client: Mowlem (for DLR)
Date of Award: October 2003
Date of Completion: September 2004

DLR Beckton Depot.pdf