Centaur cable saddles and accessories from Ellis have begun to be installed in National Grid’s London Power Tunnels project
The cable saddles, which are being used to secure high voltage (HV) cables throughout 32km of tunnels under London, were specified in 2012 in a record £1.5m order for the Yorkshirebased cable cleat manufacturer.
Richard Shaw, managing director of Ellis, said, “While it’s always great to secure a new specification, especially such a large one, it’s even more rewarding seeing the product installed and being used for the purpose for which it was designed.”
In the case of the London Power Tunnels, Ellis secured the specification from Südkabel, the German manufacturer of the cables being installed in the National Grid tunnels, as a result of a design that saw them deliver a product that overcame a serious safety issue surrounding the restraint of HV cables up to 400kV with a diameter range of 100-160mm.
“At the time we designed Centaur neither the British nor European Standards took into account cleats on HV cables of this size,” explained Shaw. “This meant those specifying for such jobs were very much in the hands of the manufacturers, who in most cases simply provided warranties for their products.
“The problem with this was that none of the products available had been short circuit tested, and so the warranties were based purely on calculations and mechanical tests. As such there was no proof the saddle cleats being used would withstand the most testing elements of the job they’d been specified for.”
Prior to launch Ellis put its new heavy duty extruded aluminium product through the most rigorous of testing procedures. Using cable manufactured by ABB in Sweden, the company shipped the Centaur cable saddles and ABB cable to the Netherlands where they were tested to 163kA peak and 63kA RMS for one second, in both 3-phase and phase-tophase fault scenarios.
“We invested well over £100,000 in designing, developing, testing and bringing Centaur to market,” added Shaw. “At the time this was the largest amount we’d ever invested in one new product, but we did so with confidence that it had the potential to solve a major safety issue and fill a gap in a growing market sector – a confidence that was quickly proven to be well placed.”
T: 01944 758 395