The Millharbour Sewer Diversion Project in London included the tunnelled diversion of a large 1500-mm-diameter sewer to facilitate designing and constructing a new sky rise multi-use development.

The work involved a detailed route selection with consideration of extensive utilities, including fibre optics and the Docklands Light Railway. Extensive site investigations and consultation with utility providers were required in advance to determine the exact location of services. The drive and reception shafts were then designed with extensive consideration of the temporary works requirements as a result of the major spatial restrictions.

In one location, the services were so dense that conventional top-down shaft construction was not possible. Instead, Nicholas O’Dwyer completed a bespoke design for a no-dig lateral connection into an existing 1600-mm-diameter sewer by pipe jacking techniques using a prefabricated cutting shoe. This required extensive structural and geotechnical modelling of the ground conditions and cutting into the existing pipe.