The three consortia are; BMB (Balfour Beatty, BAM Nuttall and Morgan Sindall} which has the contract for the shorter western tunnel drive, FLO (Laing O’Rourke and Ferrovial Agroman) which has the largest Central section drive and CVB (Costain, Vinci and Bachy joint venture) won the eastern section. All three have slightly different mobilisation and construction timescales.

Once fully operational, construction will span 21 large, complex worksites across 15.5 miles (25km) from the storm tanks in Acton to Abbey Mills pumping station. The preliminary construction works are currently underway at the four key drive sites with work started at a further nine sites across London.

During the mobilisation phase, when power was not available, G4S deployed an innovative stand-alone, mobile camera surveillance tower. These towers are self-sufficient and powered by hydrogen. The data and footage collected is transmitted using a 4G network to the central control room. The systems are effective, high quality and quick to install.

G4S Tideway Project Account Director, Tarquin Halse, said: “The tactical and operational planning that has gone into providing the security at each of the sites and as part of the whole project is immense. We are working closely with all of our partners to ensure that ramp up is smooth and that our around-the-clock security is thorough and highly-responsive, all of which is monitored from our central London command centre.”

G4S has installed Avigilon cameras and motion sensors at every Tideway construction site as part of the security and monitoring framework. The is part of an integrated surveillance system which also includes automated number plate recognition, intruder detection and infrared, to enable visibility in bad weather, fog and darkness without using white light.

This integrated security network sends data and information to G4S’s command centre, where it is collected and assessed using data analytics software in real-time. A proactive approach mitigates the likelihood of incidents or safety issues and the data is acted upon where necessary and a picture of information is collated to inform the potential action taken.

“Our command, control and communications centre is at the heart of the network of surveillance and security that we provide. When fully operational, all of the voice and video security data collected from across the sites will be checked and analysed and reacted on by our highly trained team of security officers and managers,” Halse said.

The high-definition cameras survey and analyse the entrance and perimeter activity constantly. The cameras interpret and learn what ‘normal’ behaviour looks like. If a person enters the site area it does not recognise, the system will flag this. Equally, it will recognise any unusual behaviour and has in-built thermal imaging capabilities.

Across the entire project, G4S will install Avigilon cameras integrated with Symmetry access technology at all pedestrian perimeter access points (PAP), turnstiles and internal site access points as well. At peak construction, G4S expects there to be many 100s of people passing through the different Symmetry access controlled zones within each of the large works sites on a daily basis.

Every Tideway construction site is organised into zones, each of which has its own level of security access clearance and construction workers must go through additional Symmetry security checks to gain access. The zone closest to the tunnel construction site has the highest level of restrictions, so that only those directly involved in the tunnel construction and the correct training and credentials, are able to enter that zone.

Tarquin Halse said; “It is really important that our security solution works in line with Tideway’s focus on health and safety across all the sites. The access security is key to knowing exactly who is on the site at all times, whether they are in the right zones and that they have the correct security clearance. This is supported by our highly trained, well managed and construction orientated security personnel on site.”

At its height, there will be more than 4,000 people working on the project and by 2020 there will be 400 G4S security officer roles on the project. Tideway envisages that it will be a good source of sustainable jobs for London for the entire project and beyond, providing a cleaner, healthier River Thames.