WET News

ONSITE XXXXXXXXXX 8 WET NEWS JUNE 2015 L anes Group has been trialling a vacuumation system on the London Underground to solve 'one of the most notorious' drainage maintenance problems on the Tube network. Working in partnership with the London Underground, Lanes has tested the Big Brute technology on the Metropolitan Line north of Baker Street, which has one of the most challenging track drainage systems on the Underground. The new cleaning technique is expected to improve safety, reduce waste sent to landfill, improve operational outputs, and contribute significantly to service reliability, reducing the risk of costly service failure penalties. Dubbed Big Brute, the machine is being tested on a four mile section of the Metropolitan Line between Baker Street and Finchley Road, known as M100. Not only is this stretch one of the oldest sections of the London Underground system, it is one of the busiest sections of the Tube. However, it suffers signal failures up to 50% higher than the average, with one of the main causes being water levels rising in the tunnels, tripping signalling equipment. The problem is made worse by the ageing condition of the pipes and the 'cut and cover' design of the tunnel, which lets more rainwater onto the track. When combined with the clogging effect of London clay, the track drains become difficult and costly to clean. The conventional cleaning method is to pull or push silt and debris into drainage catchpits with rods, then use shovels to collect it, bag it and send it for disposal as contaminated waste. However, the track drainage, dating from the age of steam, is in the tunnel invert, beneath the negative rail, so is hard to access. The catchpits have only shallow sumps. In a third of them, there are no sumps at all. This makes it difficult to collect the clay sediments, which liquefy when disturbed, then move along the pipe and settle again. This means the waste collected is up to 80% water. Liquefied clay Big Brute is designed to over- come the problem by using powerful vacuum pumps to suck up the liquefied clay. It is collected in a drum, where most of the water is extracted and reused to flush the drain lines. The waste, this time up to 80% clay, is pumped into another drum, and bagged, ready for disposal. The compact technology, designed and manufactured by Michael Williams Engineering in Cambridge, was developed for grain handling and storage. Later, wet vacuumation models were developed to clean oil pumps. The innovation of using the machine for track drainage was instigated by London Big Brute keeps drainage cleaning on track • Ageing pipes and clogging from clay means London's Tube track drains are difficult and costly to clean. Is Lanes' Big Brute the answer? ONSITE DrAINAgE mAINTENANcE projects specs • Investigate ways to improve maintenance of ten sites with the worst track drainage on the London Underground • Trial new technology to overcome track drainage issues • Set a new gold standard for track drainage cleaning on the Tube techknow • Big Brute uses vacuumation technology, namely powerful vacuum pumps, to suck up the liquefied clay • The waste is collected in a drum, where most of the water is extracted and reused to flush the drain lines • The remaining waste is pumped into another drum and bagged, ready for disposal • The new technology will improve safety, and reduce waste sent to landfill • The technology could prevent the need for man-entry in deep sump cleaning neeD to know 1 The conventional cleaning method is to pull or push silt and debris into drainage catchpits 2 The metropolitan Line between Baker Street and Finchley road, known as m100, is one of the busiest sections of the Tube 3 m100 suffers signal failures up to 50% higher than the average 4 The compact technology was developed for grain handling and storage the VerDIct • "We can see a number of other applications for Big Brute for railways, from preventing the need for man-entry in deep sump cleaning, to floor channel cleaning around stations. We're excited by the possibilities" matthew Todd, Lanes Underground asset manager Mohamed Chergui. He had already asked Lanes to look into ways to improve maintenance of ten sites with the worst track drainage, including M100. He then designed his own vacuumation cleaning machine, and showed his idea to Lanes project supervisor Trevor Osborne. Osborne had been researching the same problem, and mentioned the Big Brute technology. Confined space Both engineers visited Michael Williams Engineering, where the design team agreed to adapt one of their wet vacuumation machines so it could be used in the trial. Chergui devised the project plan to test the technology, which was approved by London Underground. He says: "It could be revolutionary for track drainage cleaning on London Underground. The benefits, so far, are very clear. "We will go from a section of track being the worst for track drainage problems, to being no worse than the average. The benefits of this, in terms of service reliability and the reduced risk of service penalties, are very big. There is no reason why all track drainage cleaning should not be carried out this way." Osborne adds: "The health and safety benefits, with reduced manual handling and confined space entry, are significant. There will also be operational improvements, with cleaning cycles along M100 reduced from up to four a year to one or two, and with a smaller team." Lanes Rail Division commercial director Matthew Todd comments: "We can see a number of other applications for Big Brute for railways, from preventing the need for man- entry in deep sump cleaning, to floor channel cleaning around stations. We're excited by the possibilities. "If the trial proves a success, we hope London Underground will approve the system for use, and we will be able to set a new gold standard for track drainage cleaning on the Tube. The Big Brute technology, which is being tested on the London Under- ground's metropolitan Line, uses powerful vacuum pumps to suck up liquefied clay The 'cut and cover' design of the tunnel lets more rainwater onto the track "We are delighted with the outcome of the trial so far, with significant amounts of the problem clay removed, resulting in the drainage pipes working much more effectively. This very compact, mobile and powerful vacuumation technology appears to have wide applications for track drainage maintenance, making cleaning faster, more effective and safer." n

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