Thames Tideway Tunnel

The Thames Tideway Tunnel – or ‘super sewer’ is an under-construction 25 km tunnel running mostly under the tidal section of the River Thames through central London. It will eventually provide capture, storage and conveyance of almost all the combined raw sewage and rainwater discharges that currently overflow into the river. There are currently 350 discharges into the Thames every year from the existing Victorian sewer system, which this project will ultimately alleviate.

At 25 kilometres long, up to 66 metres deep and more than seven metres wide, the £4 billion project will be the biggest infrastructure build ever undertaken by the UK water industry. It will generally follow the route of the River Thames, enabling it to connect to the ‘combined sewer overflows’ dotted along the riverbanks, passing beneath all other infrastructure in London and through a variety of different ground conditions. The project is still in its infancy and set to run until 2025. Next to HS2, it’s the largest high-profile project in the UK at the moment.

Mane has been contracted by its client, Laing O’Rourke, to supply talent for the largest central section of the site to Kirtling Street, along with some smaller satellite sites. It is one of just two suppliers providing labour for the larger site. The recruiter is on the supply chain to provide not only mechanical and electrical skills, but also specialist marine labour. The project is currently at the stage where the shaft is built and tunnel boring machines (TBMs) are about to be lowered, which will be tunnelling under London for the next two years.

A TBM tunnels through the ground using its rotating cutterhead, simultaneously creating the tunnel walls with prefabricated segments of concrete. Spoil from the digging must be removed by conveyor (or by pipe, if the spoil is in a slurry form), while segments of concrete must be continuously delivered to front of the machine.

Mane is supplying electrical labour to work on various areas of the site, as well as the TBMs themselves. Finding professionals with this specialist skill sets can be a challenge. It is vital that contractors have solid experience in the mining or tunnelling industries previously, specifically working on TBMs and similar equipment. Mane called on its talent reach and network to source these skills from the UK where possible, bringing contractors across from other major projects, such as Crossrail.

However, the scale of the project means that talent also has had to be sourced from overseas. Mane has tapped into its international networks to bring in specialists from areas such as Ireland - which has a strong mining industry and healthy talent pools - to meet demand. 

Mane has also utilised its extensive reach in contiguous sectors to source the required marine labour - which are the people to deliver that spoil at the bottom of a 62 meter shaft via a crane to a barge on the Thames, which delivers it to Tilbury in Essex to create new wetlands for birds.   

This project is also somewhat challenging due to the level of compliance required. It is the first construction project in the UK which seeks a fifty-fifty split between men and women across the board - and there are few female TBM electricians. It is also very stringent in terms of a percentile of talent that must be sourced from local boroughs as well as a certain mileage away from the site, which has the potential to be difficult in terms of recruitment.

Mane is working with London Build and local housing associations and councils to draw talent from these specific underrepresented groups into the market, to identify candidates that have the right skill sets so that it can offer them additional training to get them on to these type of projects.

Another challenge is that contractors are required to be taken on board through direct employment. Getting contractors to buy-into a PAYE form of employment can be fairly difficult. However, because of Mane’s experience on Crossrail and other projects where it has demonstrated compliance in this area, contractors trust Mane to look after their best interests.

Mane won this contract because of its extensive knowledge and experience of this type of niche work. While this project is still ongoing, the client is so far very impressed with delivery.