NTTX was commissioned to undertake the detailed design, installation and commissioning of a PLC-based control system for the traction power network, as well as the electrical interlocking of the HV network, on the DLR extension to Stratford International. Traditionally, this kind of work has been implemented using relays – NTTX’s use of PLCs was a novel approach as far as the client was concerned.
The extension of the DLR from Canning Town to Stratford International is part of the campaign for regeneration of the Lower Lea Valley, offering users improved public transport capacity and increased reliability, as well as preparing the way for the anticipated extra pressures on the service when the Olympics come to London in 2012.
The extension uses the North London Line (NLL) route from Canning Town to Stratford Regional, then heads north by slewing the tracks east of Channelsea Junction and extending round to Stratford International (SI) station. The route length from Canning Town to SI is 4.8km, along which are three previously existing stations and four new stations. The traction system comprises two existing and two new substations and one new track paralleling (TP) hut.
NTTX was contracted to supply the Intertripping, Interlocking and Mass Trip Control Equipment for the project.
“The work we supplied on the Trip Control Panel application software was independently assessed by ERA technology as having been developed in a manner consistent with Safety Integrity Level 2 (safety-related equipment) standards,” says Gary Fardon, Controls Director. “We’re very proud of that, because you need rigorous quality and software procedures to be able to deliver to this level.”
Erik Twigt, project manager (systems) for Skanska VolkerRail JV, comments: “This project was quite complex and unique in that the introduction of the PLC-based control system was the first of its kind on the DLR network and therefore presented many assurance challenges.
“Throughout the duration of the project NTTX has provided a very professional and reliable service whilst meeting some very challenging deadlines. I am looking forward to working with NTTX again on our future projects.”
