How Tideway got back to work

Work on London’s super sewer Thames Tideway – one of the largest infrastructure projects in the country – has resumed this week after pausing all but essential works during the lockdown.

Programme director Andy Alder talks Utility Week through the measures the company is putting in place to protect the health and safety of workers including a traffic light system for different working areas and tailored travel plans for staff commutes.

Alder explains that at the start of the Tideway project, a process called Right Start was carried out at every site to ensure all jobs could be carried out safely and facilities were suitable. This procedure was repeated to reassess all  activities for returning workers to be able to observe social distancing.

Alder sets out how all tasks and areas were labelled using a traffic light system.

Green areas are those where people can easily work apart with no problem; amber are where there may be a risk of coming into contact with others, so extra controls would be needed.

Red areas are those that require people to be closer than two metres apart. Assessments were made on these tasks to let staff work as safely as possible by minimising the time taken, having hygiene arrangements in place and providing additional PPE.

“We also went through a rigorous process to understand all the sensitivities for staff and stakeholders in the local communities,” Alder says. “We ensured we communicated our plans with those communities in case any unusual concerns or challenges were raised.”

These include individual travel plans for all staff to avoid public transport wherever possible, encouraging people to walk or cycle wherever possible and making provisions for people to use private cars if that was the safest way to travel.

At each of the Tideway locations social distancing measures have been implemented in communal areas and changing rooms, and spaces left between desks to let people work at distance.

Other measures include on-site briefings being divided into smaller groups to minimise the numbers of people in any room.  Onsite, one-way systems have been adopted on pedestrian walkways so people do not need to cross each other.

Alder says the changes were incrementally introduced and trialled as activities with smaller numbers of people resumed on different sites. Feedback from the workforce will inform how practices need adapting as more staff return to sites.

During lockdown safety critical work and monitoring continued but the decision was made to temporarily stop work across all sites to get the correct safety arrangements in place to restart work safely.

Alder says the heavy emphasis on health and safety throughout the project, including solid emergency response plans, put Tideway in good shape.

“Those kinds of mechanics and systems were great for reviewing the situation as it was developing and making sure we were taking coordinated action in response to it.”

The decision to cease work was assessed as it became apparent that the virus would impact daily life.

“As the situation was unfolding in other countries, we were keeping an eye on the work we were doing on sites and what things we would have to finish prior to shutting down. It became a day to day part of how we were doing our business,” Alder says.

These must-finish tasks included shafts that still needed a base slab. Alder explains certain pieces of heavy machinery including a pipe jack machine would not be sensible to stop because of the difficulty to restart.

“We worked with the contractors there on the site to put social distance measures in place on site so the workforce was able to finish that work. Some carried on during the Covid-19 restrictions because it would have been a health and safety and technical challenge if it just stopped.”

These included two tunnel boring machines that were in critical positions – one at Hammersmith Bridge and a second underneath flood defence river walls in east London – which could not safely be stopped.

“For both of those we planned on where we needed to get the tunnel boring machine to before we could safely pause that work. We kept the work going with reduced workforce to get to a safe place so that we didn’t cause any additional ground movement or put primary assets at risk.”

Before lockdown began, the teams had taken the project past its half-way point with excavation completed on 18 of the 21 shafts and 14km of tunnelling done. Alder says they were a long way through the “heavy civil engineering” and the next phase will be on work to connect the Thames Water sewer network to the internal structures.

The estimated completion date is in 2024 but the length of delay because of coronavirus will not be known until the ramifications of the epidemic are fully known.