Kilkern is pleased to see a crane has moved into place at Blackfriars Bridge signalling the start of the Thames Tideway project. As someone who owns a construction recruitment company and who has grown up in London and managed to avoid swimming or fishing there despite these being two of my favourite hobbies I’m truly excited about this project.
What is Tideway?
Tideway is a massive tunnelling and environmental improvement project which in pioneering in terms of how it is being procured and engineered and financed. It includes a 7.2m diameter 25km-long tunnel, up to 65m below ground. It will run from Acton to the Abbey Mills Pumping Station in Stratford, mainly under the river. It will collect sewage that currently pollutes the Thames. Every year 39 milliontonnes of sewage flows into the river. This pollution causes damage to fish and plant life and also makes the river unappealing for swimmers.
Why do we need it?
The amount of sewerage flowing into the Thames is the equivalent of 8bn toilets flushing into the river. The London sewer system is no longer fit for purpose. Most of London’s sewer systems were constructed over 150 years ago by Sir Joseph Bazalgette. Although the brick-constructed tunnels are still structurally sound, they were not built to manage to capacity of the modern world. During the 1860’s London has a population of 2 million whereas now there are 8 million people.
London has a combined sewer system. This is when storm water runoff and wastewater go into the same sewers. On a normal day this is fine but during a rainstorm it’s a problem. When it rains heavily such as with the recent storm Desmond the sewers fill up quickly, and the dirty water needs to go somewhere. The sewers are designed to overflow into the Thames as otherwise they would flood our houses or the streets. There are 57 ‘combined sewer overflows’ (CSO) on the Thames. In the 19th century, engineers designed the sewers to overflow about 12 times a year. Now it happens about 60 times per year. CSO’s pollute the Thames. London for this reason is in breach of the EU Urban Waste Water Directive.
Why do the sewers overflow so often?
Sewers overflow more often now than when they were built. One is because of the increase in the ‘base flow’, the dirty that flows more or less consistently each day from houses. The other is the increase in ‘storm flow’, water entering the sewers when it rains.
There are twice as many people in London now as when the sewers were built which increases the base flow. Also since the early part of the century London has paved over more areas. This provides less opportunity for water to seep into the ground. There were alternatives put forward to the super sewer including increasing the number of roof gardens, water recycling plants and also wall gardens all of which would have the potential to recycle storm water. These environmentally friendly initiatives definitely need more investigation. Green infrastructure will be increasingly important in the future and is where the industry is heading. It will still be important even when the tunnel is built. Water not getting into the sewers equals less sewage to pump and treat. Pumping and treating takes a lot of energy. Meeting London’s carbon emission targets will be easier if we use less energy. However the super sewer is still a necessity in order to provide sewerage system fit for London in the 21st century.
How will it work?
The Tideway Tunnel will intercept sewage before it overflows into the Thames. Instead of flowing into the river, the dirty water will be stored in the super sewer. It will then be pumped to the Beckton Sewerage Treatment Works. Once treated, the clean water will be finally released into the river.
Who will pay for it?
The project is estimated to cost ?4.2 billion. Customers will pay for the sewer through their water bills, which are forecast to rise by ?80 through to 2020. ?1.4bn of the Thames Tideway Tunnel?s construction cost will be financed by Thames Water and 2.8bn by Thames Tideway Tunnel Ltd. Thames Water?s contribution will fund development costs, enabling works and interface works. Bazalgette Tunnel Ltd will be building, operating and maintaining the super sewer. Bazalgette Tunnel Limited, shareholders are a consortium of city investment funds including Allianz, Amber Infrastructure Group, Dalmore Capital Limited and DIF.?The UK government is also providing guarantee for the project in case of unanticipated costs and risks. This is a new investment and delivery model, developed by Thames Water, the Government and Ofwat. Paid for by the people, backed by the government and the rewards go back to investors and also the local community. The infrastructure provider will be independent of Thames Water and will have its own license from Offwat. The Infrastructure Provider’s will manage the contractors, who will construct the Thames Tideway Tunnel and will be chaired by Sir Neville Simms, with former Crossrail Programme Director Andy Mitchell as CEO.
Who is constructing the project?
A joint venture between Laing O?Rourke and Ferrovial Agroman won the largest Central section drive worth 600m-900m. The Eastern section of the tunnel worth approximately 500-800m was won by a Costain, Vinci and Bachy joint venture. Balfour Beatty, BAM Nuttall and Morgan Sindall picked up the western tunnel drive, worth somewhere between 300m-500m.
Innovative engineering in the design phase has reduced the overall cost of the project by reducing the number of stations required to build the tunnel and also reduced the actual length of the tunnel itself. The construction is programmed to complete in 2023.
How will it be built?
There will be 24 sites across London during the construction of the tunnel. Also there will be three main “drive sites” where tunnel boring machines (TBMs) are lowered into the ground. The sites preparation will include setting up offices for the armies of civil engineering workers and barge facilities for the transportation of the muck away. Large shafts will then be sunk from which the TBM’s will be launched.
Tunnelling will be undertaken 24 hours a day, 7 days a week at several locations at the same time. The tunnelling process will be similar to Crossrail where concrete segments will be laid along the tunnel as the machine passes through. Shotcreting will then take place the line the tunnels to complete the process.
The tunnel will be a meter deeper for every 790 m it travels, so that it allow the sewage to flow from one end to the other. It will pass within metres of existing tube lines.
The crane was being put into place by Volker Stevin this week which signalled the start of the works was for the relocation of the Thames Clipper Ferry. Tideway are building a new pier for the Thames Clipper River bus users who are having to move their own pier due to the location of the works. The seven metre barge used to transport the crane had to pass through seven bridges in order to get to the eastern side of Blackfriars bridge where the clipper services is being located during enabling works.
The Thames Tideway Tunnel project will create more than 4,000 jobs directly on the works, and another 5,000 jobs indirectly. It will also offer hundreds of apprenticeships and work placements. In order to qualify for the works contractors had to show a commitment to employing people through the local community. There is also expected to be a boost to the local economy through wildlife and sporting activities being reintroduced to the Thames.
For employment opportunities at Tideway it is possible to contact:
Tideway, www.tideway.london who are currently advertising roles on their website.
If you need to recruit people for Tideway.?
If you are involved in recruiting people for the Tideway project do not hesitate to contact Kilkern. We are a market leader in labour hire and recruitment services for the infrastructure, utilities and construction sectors. We typically supply all the people and services needed to run construction projects including labour, supervisory and engineering staff, plant and training. We have separate divisions servicing water, rail, metro, power, tunnelling, utilities and the built environment and operate across many of the largest projects in London the UK and Ireland. Kilkern was involved in supplying people for the Crossrail project and also supplied contractors working on AMP5 programme of works for Thames Water including Barhale, Clancy Docwra and Murphy. Kilkern are also preferred suppliers to Balfour Beatty and Skanska who are now heavily involved recruiting for the AMP6 programme of works. Patrick Curran the Managing Director and owner of Kilkern is also a Non Executive Director and family shareholder of Barhale Plc a leading civil engineering contractor who are also heavily involved in Tideway civil engineering works through early contractor involvement. Barhale will be involved in shaft-sinking, utility diversions and tunnelling projects throughout the duration of the works.