February 1st 2011As mentioned elsewhere in this issue, the cooling of London Underground's deep tube has been challenging engineers for years. In 2008, Transport for London established a dedicated programme team to work on a variety of solutions including mid-tunnel ventilation and cooling, station cooling and regenerative braking on vehicles. A year later, work was underway on the first two of three tranches of improvements to tunnel ventilation.
Mansell Construction Services was awarded a £6 million contract as part of this programme and, for Tranche Two, they asked process control systems specialist FIRSTCo to work on the cooling fans and dampers which were to be installed at four mid-tunnel ventilation shafts (MTVSs) on the Victoria line, doubling air-flow through these sections. The control system consisted of a network of programmable logic controllers (PLCs) that interfaced to a central cooling system, providing operators with real-time monitoring and performance trending. This control system architecture required the design of an extremely robust network to cope with the harsh underground environment.
In 2009, Westermo Data Communications was approached to supply much of the industrially-hardened networking equipment used to connect the central cooling system to the PLC equipment which provides the control and monitoring functionality within the four MTVSs. It had been decided at an early stage to adopt ADSL as the communications technology. PSTN circuits already existed which could be easily migrated over to an ADSL service giving good reliability and the level of performance required from the network.
By using Westermo routers, IP traffic could be transferred at rates of up to 8Mbit - broadband speed. This high bandwidth ‘always on' connection enables engineers and operators to make informed decisions based on alarms indicating fault conditions generating from the shaft and station plant. Additionally a data historian was used to provide real-time data logging and archiving functionality generating performance reports for the client.
The success of this project and the partnership with FIRSTCo has prompted Westermo to host a conference at the London Transport Museum on 23rd March 2011 when speakers for the two principals, as well as Network Rail and Invensys Rail, will explain their robust data communications solutions for the rail industry. Attendance is free and to register please visit... www.westermo.co.uk/registration