INNOVATION Reconnecting London with its river Tideway THE TUNNELLING THE New Civil Engineer SAFETY DIVERSITY & Major Project Report COMMUNITY COSTAIN, VINCI CONSTRUCTION GRANDS PROJETS AND BACHY SOLETANCHE ARE PROUD TO DESIGN AND BUILD THE 10KM EAST SECTION OF THE THAMES TIDEWAY TUNNEL. Our Joint-Venture has been certified ISO 9001:2015, ISO 14001:2004 and BS OHSAS 18001:2007. We aim to deliver not only shafts and tunnels, but also reconnect London with the river Thames. Scan the QR code to view the route of the tunnel. VCGP_06 TIDEWAY NCE - V05.indd 1 24/05/2016 14:34 Contents TIDEWAY REPORT JULY 2016 04 Overview Tideway chief executive Andy Mitchell explains the philosophy of the Thames Tideway Tunnel, which will take sewage from combined sewer overfl ows along the tidal Thames for treatment at Beckton Sewage Treatment works 10 Project engineering How the £4.2bn Tideway project crosses London from Acton in the west to Beckton in the east, connecting with combined sewer overfl ows on the way 12 West section 16 Central section 24 Good Neighbour: Helping the local community understand The 7km West section runs from Acton Contractors working on the 13km the project to Wandsworth following the route of the Central section of the tunnel also have 26 Diversity: Tideway wants its Thames. Work has to be programmed to to build eight access shafts and must workforce to refl ect the communities account for major events like the Oxford repair and rebuild river walls as well as it will serve and Cambridge University Boat Race and reclaiming land from the Thames to the Chelsea Flower Show create a work platform at Blackfriars 28 Low carbon: Work to limit the project’s environmental impact 20 East section 30 System integration: Ensuring seamless transition from construction Value engineering has driven to operation innovation and programme savings 32 Who’s who: Profi les of some of on the 5.5km East section between Tideway’s key players Tower Bridge and Bermondsey where variable ground conditions present a 34 Alliancing: Collaboration and The tunnel follows the route of the Thames major challenge customer focus are key JULY 2016 NEW CIVIL ENGINEER 3 Overview TIDEWAY SYSTEM TIDEWAY REPORT Cleaning London’s river artery BY MARK HANSFORD ince legendary perfectly good rainwater with sewer engineer Sir Joseph water?” he asks. “No. But we are London has S Bazalgette built where we are.” £4.2bn forgotten his sewers And London is not alone, says Total cost the population of Mitchell. “When you look around the river and the London has grown from just over the world there are many cities of Tideway 2M to 8M. that either have or are planning project significance it can While Bazalgette had the foresight similar things. Singapore is currently to design the system to serve 4M – procuring the second phase of its play in the way and while only 6.5M of those 8M are Deep Tunnel Sewerage System,” 39M.t directly contributing to the sewer he explains. “And our system is “London works Annual flows – it is simple maths to see designed to be what a lot of these ANDY MITCHELL, the system is well beyond capacity. systems are designed to be: transfer amount TIDEWAY CHIEF EXECUTIVE Historically the result has been that and storage.” of sewage 39M.t of combined sewage spills out And that is why it is so big. “It’s into the Thames in a typical year. It a reservoir as well as a transfer currently is unacceptable and it is time to act. tunnel. So the tunnel has to be the discharged “London is growing and the sewer diameter it is to create the volume,” into the tidal flows are rising, whichever way he says. you look at it,” says Tideway chief Starting in Acton in west London, Thames executive Andy Mitchell. “It is only the main 25km long tunnel generally ever going to get worse.” follows the route of the River The Tideway project, at a cost Thames to Limehouse, where it then of £4.2bn (in 2014 prices), is a bold continues north east to Abbey Mills solution. But, says Mitchell, it is the Pumping Station near Stratford. only solution that deals with the There it will be connected to the legacy problem. Lee Tunnel, which will transfer “If you were designing a system the sewage to Beckton Sewage from scratch, would you combine Treatment Works. Along the way it A combined sewer overflow in Vauxhall 4 NEW CIVIL ENGINEER | JULY 2016 doesn’t make sense.” TIDEWAY SYSTEM Mitchell absolutely cares about the bigger picture and the entire Tideway project has to be seen as more than building a tunnel, he insists. “Our vision is a bigger one. London has forgotten the river and the significance it can play in the way London works,” says Mitchell. “Why is London not in love with its river like Paris is in love with the Seine?” Tideway has a raft of initiatives in place to help make this reconnection a reality. Many of them are social in nature, but others have a clear commercial slant. One such is the Thames Skills Academy, RIVER THAMES which Tideway is supporting along with the Port of London Authority and Transport for London. “We are going to train some 300 new people Victoria Embankment to work on the river to do the work Bazalgette’s original we are going to need,” says Mitchell. sewer “In doing that we are going to prove you can support a time-critical 24/7 Thames Tideway Tunnel operation in a safe way using the river. And after that, the answer Combined sewer can’t be for that skills base to overflow will connect dissipate. These skills have got to be to Tideway shaft taken up by others.” Mitchell and his team is also Sewage flows from hugely aware of the need to be base of the shaft to a good neighbour (see page 24). the Thames Tideway After all, unlike Mitchell’s previous Tunnel project, Crossrail, where he was programme director, most of those affected by the seven years will connect to over 30 combined storm water and therefore is much of construction stand to make no sewer overflows (CSOs) that are more diluted. obvious gain. Indeed all that most located along the riverbanks. “So if we are somewhere in the 50/50 will see is an increase in their water The main tunnel’s diameter grows region of a 96% reduction in spills Targeted bills to pay for the project, although from 6.5m to 7.2m diameter as it we are reducing the actual volume of this increase has been significantly heads east, descending from 30m sewage spilt into the Thames much gender split reduced. to 66m below ground in doing so, more than that,” notes Mitchell. within project And that desire to get in and get and the Thames Tideway Tunnel That is, of course, if nothing done was a major driver behind combined with the Lee Tunnel will changes. But if London continues to team by Mitchell’s push to speed up delivery have a combined storage capacity of grow and rainwater continues to be project end and knock up to two years off the 1.6M.m3. allowed into the sewer system then construction programme. But it will still sometimes not be the number of spills will increase. Being built from three main enough to totally eradicate spills: So for Mitchell the tunnel cannot construction drive sites in Fulham, “Today, around 60 times a year there be seen as a panacea. Sustainable Wandsworth and Bermondsey, using is a spill,” explains Mitchell. “The drainage solutions (SuDS) must also six tunnel boring machines (TBMs), Thames Tideway Tunnel will play a come into play. the project was expected to take big role in reducing this to less than “The argument around whether up to seven years to complete. The four. But if you look at what it would we build the tunnel or look for SuDS geology varies with the western take to reduce this to no spills at became a binary argument,” says section in predominately London all, it would have to be double the Mitchell. “The reality is we need Clay, the Central section being bored size and it gets to the point where it to do both. The tunnel is the only mostly through Thanet Sands and doesn’t make economic sense.” volume fix we have to solve the the Eastern section largely through He also points out that the tunnel problem we have now. But going chalk. Work will require the use of will only hit capacity during pretty forward, we need to do more with 24 construction sites, 11 of which serious storm events, and only then SuDS. London has got to get way are located along the riverbank. after what was already sitting in the smarter through planning. We have Many are in residential areas. With sewer system has been flushed into got to get more intelligent in how we the main construction work already the tunnel – meaning what is left deal with the resources we have and scheduled to start in 2016, speeding to overspill contains much more throwing good water into a sewer up the programme was almost JULY 2016 | NEW CIVIL ENGINEER 5 BOOK NOW CALL: 020 3033 2609 6-7 JULY 2016, INMARSAT, LONDON EXPANDING AND FUTURE-PROOFING THE UK ROAD NETWORK KEY SPEAKERS FOR 2016 Jim O’Sullivan David Brown Peter Antolik Laura Shoaf chief executive chief executive highways director strategy director Highways England Transport for the North Office of Rail and Road for transport West Midlands ITA Anthony Smith Nick Reed Dr Jo Blewett Parvis Khansari chief executive director programme manager – associate director - Transport Focus Transport Research A9 Dualling highways & transport Laboratory (TRL) Transport Scotland Wiltshire Councilbut 3 WAYS TO BOOK YOUR PLACE: roads.newcivilengineer.com/attend 020 3033 2609 [email protected] Gold partners Silver partners Media Partner NCE_CONF15_ROAD_FPAD_NCE.indd 1 25/05/2016 11:58 TIDEWAY REPORT unthinkable at contract award late last year.