Purpose

Thames Tideway Tunnel is one of the UK’s biggest and most complex construction projects of recent years. It involves the construction of a huge new ‘super sewer’ deep below the River Thames, to vastly increase the capacity of London’s creaking wastewater network and reduce the number of polluting spills.

We were involved right at the outset of the project. In order for others to be able to construct access shafts and infrastructure for the tunnelling works, our marine construction specialisms were needed to relocate two permanently moored vessels, the Tattersall Castle floating restaurant and HMS President, by creating new permanent berthings. We also needed to replace the Millennium Pier in a new location, to allow visitors continued access to the River Thames. All of this needed to be delivered against the logistical and stakeholder challenges of working in central London – within sight of Big Ben – and the programme pressures of the multi-billion pound follow on works.

What we did

During the Early Contractor Involvement period, we co‐located ten construction experts with Tideway and their designer Arup, to develop work methods, procure long-lead items and prepare 170 consent applications. We adapted working hours and methodology, to limit noise during exams at the neighbouring City of London School and performances at the Globe Theatre. Advanced planning removed unexpected delays.

We used pre-fabrication to save time and money during installation. Blackfriars’ new pier, walkways and bankseat were fabricated in the Netherlands by specialist supplier, Ravestein. These prefabricated components were fitted in just over one week. The 84m-long pontoon was transported across the North Sea on a submersible jack-up barge. We moored it against two 32m-long tubular piles. We had driven four tubes to support the bankseat and two smaller ‘hospital’ piles from which we hung the 60m long canting brow.

We completed the Blackfriars works by installing stairs and a lift for the public to safely access the new pier.

We also relocated the Tattershall Castle and HMS President upriver from the tunnel’s construction footprint and installed sheet piled walls, mooring piles, brows, access steps and services, before floating the vessels to their new location and demolishing the previous moorings.

Project successes

We got the Tideway programme off to a great start by successfully completed the enabling works on time. Passengers began using the new ferry service from the relocated Millennium Pier in October 2016 as a visible sign of Tideway’s progress.

This was Tideway’s first project undertaken on the Thames and tested and proved the consenting processes. This included the four‐way legal agreement between Tideway, the Environment Agency, Marine Management Organisation and Port of London Authority. Our collaborative efforts were recognised when we were shortlisted for the British Construction Industry’s ‘Partnership Initiative of the Year’ award.