Digital approach to construction of London’s super sewer
Digital processes and innovations are enabling the Thames Tideway tunnel team to respond to change, make confident decisions and improve safety and efficiency on the project.
The Thames Tideway tunnel is a 25km super sewer being built under the River Thames, from the London Borough of Ealing in the west to the London Borough of Newham in the east. Costain is one of several joint venture partners, including VINCI Construction Grands Projects and Bachy Soletanche, delivering the east section of tunnel.
A digital working group was created to share best practice across six working sites in east London, with the aim of creating opportunities to use technology and smart processes to deliver a faster, greener, and more efficient project.
In recognition of the huge amount of data generated by a project of this size and the time spent on manual processes, Costain employed graduate software engineer Arkadiusz Stasiak to help implement the digital solutions to turn these ideas into reality. In the first six months, Arkadiusz introduced digital solutions including automated risk assessment and method statement (RAMS) and the construction design and management CDM hazards registers, red line drawing systems and timesheet improvements, that saved more than six thousand hours of manual labour and £85,000 per year. Monitoring and predicting temporary works design spend, is expected to bring £50,000 direct savings by reducing manual data entry and analysis.
4D digital rehearsals
The team identified the construction of the combined sewer overflow chamber at Greenwich pumping station as one of the most challenging areas of work. Complex in design, the project is being built in a constrained area of an existing Tideway site within an operational Thames Water asset. To improve the planning of the works, the team used 4D modelling techniques, intelligently linking the construction programme with 3D models of the work. The resulting 4D visualisations are a powerful visual planning tool, creating a holistic view of the programme, permanent and temporary works designs, existing site layout and construction equipment.
Video animations are created from the models for team briefings and the production of risk assessments and method statements (RAMS). This leads to simple, easy to understand RAMS, with a streamlined production and approval process. The models are also interrogated in live workshops with the construction teams and other stakeholders, to analyse different construction scenarios and identify any required modifications. This means the teams start the construction process with a clear understanding of what needs to be done and how it would be achieved, as well as an awareness of any potential hazards.
Rapid response to COVID-19 restrictions
During the first COVID-19 lockdown in early 2020, when all construction sites closed, the digital team searched for technology to help with social distancing when the workforce returned to site. Several products were tested, and Reactec’s SAFE-DISTANCE system, with proximity alarm watch, was selected for trial. The watch uses Bluetooth technology to monitor distance from other devices and beeps to warn the wearer if they are getting too close to someone else on site. A period of proactive collaboration followed, with Reactec developing and enhancing the functionality of the system. The trial was so successful that 600 watches were purchased for use on all six sites.
The site teams are now automatically informed on a regular basis of not just proximity events but patterns of social distancing behaviour, to proactively manage their workforce deployment. They are also able to act swiftly in the event of colleagues testing positive for COVID-19. Within ten minutes of a positive case being reported, the team can pinpoint who has been within two metres of that person for more than fifteen minutes and the rest of the shift is able to continue without interruption.
The team can allow remote site inspections using Realwear hands-free headsets. These enable designers, clients, and specialist subcontractors to collaborate remotely with onsite teams, which helped the project resume operations while reducing the number of people on site.
Measuring the benefits
To measure the benefits of this digital approach, the team worked with Costain-sponsored PhD researcher, Carolina Toczycka. Carolina’s work with the University of Edinburgh, part funded by Tideway, has designed a framework for the appraisal of digital investments which evaluates the strategic alignment of a digital solution to the project’s safety, programme, cost, quality, and risk commitments. The framework can be applied by the team to any potential digital solution, providing an initial assessment of the viability of the method and ongoing engagement to ensure intended benefits are delivered and maximised post implementation.
“Innovation is at the heart of the Tideway project and in this instance, the teams employed state-of-the art digital technology to enhance our works planning processes and then to respond to the huge challenges that the pandemic posed for the construction industry. With research in hand, the teams were able to rapidly measure the benefits of employing these digital technologies and not only improve our planning processes in real time but improve the safety of our people on site,” added Phil Muir, Tideway’s deputy delivery manager.