Thames uses innovative repair technique for ‘most complex’ burst pipe

Thames Water has shared details of an innovative technique it used to repair a pipe by sending engineers inside the pipe instead of patching the 90cm burst.

The work on the pipe, located eight metres below Southwark Underground station, was one of the most complex repairs the company has undertaken to a transfer main.

The team had to work around three trunk sewers, high voltage cables and other utility assets to access the pipe. The station and several roads had to close due to flooding from the burst.

Project manager Kate Cassalli explained that engineers crawled into the pipe to re-line it with pre-cast stainless steel sections using hand tools.

Cassalli said: “It became clear pretty quickly that the pipe repair was going to need an innovative approach as normal cut out and replace or relining methods just wouldn’t have worked. Cutting it out was too risky because of the other utility services directly above our main and any efforts to slide a liner through the existing pipe would have been scuppered by it having a number of 22 degree angled bends in it, which the liner would have got caught on.”

The cramped, hot conditions inside the pipe meant the two engineers could not be in the space for long.

“The innovative technique was new to Thames Water which meant planning and execution of the job took longer than a standard repair, but we managed to work underground whilst the road above was reopened to traffic and pedestrians could go about their days without knowing what was happening eight metres below them.”

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