Bond Street to Baker Street

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A section of the south bound Jubilee line between Bond Street and Baker Street had been identified as in need of repair between rings 1423 and 1781 (215mts), as the existing concrete lining (EPC) had begun to fail. London underground had installed temporary supports to minimise any risk of the lining failing, these were in the form of light weight restraints and heavy duty restraints.

These temporary supports would form part of the temporary works that would be utilized during the relining process. The EPC’s would be replaced using Spheroidal Graphite Iron (SGI) rings; these would be used in conjunction with a bespoke peace of plant known as the Segment Handling Plant (SHP). In total there were 13 x EPC sections to each ring to be removed and replaced with 5 x SGI segments.

The relining shifts were carried out with the use of 2 x SHP’s, working at opposite ends of the relining site during engineering hours from Sunday through to Thursday night, there were also a large number of 27 and 52 hour possessions that were utilised. The plant was loaded and unloaded by a team of craftsmen at Ruislip, this team also carried out the daily and weekly maintenance to both SHP’s.

This type of repair had never been attempted before during engineering hours, the team had to carry out the work in a 3hr window. Passenger trains had to run each morning with no delays.  The SHP’s were manufactured by a company in Milton Keynes and were a bespoke piece of plant. The SES operators spent time at the factory where they familiarised themselves with the operation of the plant.

Once completed the SHP was transported to a disused siding at Charing Cross where trials were carried out and a safe system of work was developed. On completion of the trials, the main work at BSBS began.  The gang comprised of an operational crew, machine fitters/electricians, hand back engineers and a maintenance crew based at Ruislip depot.  SES operated and maintained both SHP’s throughout the length of the relining work which concluded in July 2015 (3 months ahead of schedule).