You might think that digging up the road to mend a water leak or lay a gas pipe is pretty much at the rough end of the construction business – or at least some distance from the technological cutting edge.
But the utilities and streetworks sector is emerging as one area where virtual, or augmented, reality technology is making a real difference.
In the Macrh 2021 issue of The Construction Index magazine we reported on a robotic system, developed jointly by a US-based tech company and UK utilities firm SGN, to carry out ‘keyhole surgery’ on underground services.
And now Morrison Water Services (MWS) has revealed that it is partnering with highways contractor Eurovia UK on the trial of an augmented reality mapping system on its Thames Water and Yorkshire Water contracts.
MWS is using the Augmented Visualisation of Underground Services (AVUS) technology to plan and manage works more effectively by mapping and viewing underground services in 2D or 3D augmented reality (AR) via smartphone and tablet screens, prior to excavation.
AVUS was developed by Eurovia to minimise the risk of underground service strikes and third-party asset damage, as well as to improve operational efficiency and productivity by removing the need for specialist surveys.
The system maps and records actual installations as they are completed and thus ensures that the accuracy of underground service data is improved and maintained over time.
The technology offers the benefit of precise pipe location identification to within 50mm as well as the capability to capture accurate geospatial information of ‘as-built’ services before reinstatement.
Morrison’s trial of AVUS will also enable teams to benefit from as-built video capture of geospatial information prior to reinstatement of an excavation. The resulting footage is used to create detailed 3D point cloud models ensuring accurate visual records and ‘X-ray vision’ of the work completed, utility layout and geology for future works.
The initial trial was conducted by a Morrison Water Services team working on a bypass and pressure relief valve (PRV) installation in Roehampton, south London, in October 2020.
Andy Carter, MWS director of IT, innovation and improvement, describes AVUS as “a real industry game changer”.
“Using emerging and innovating technologies such as AVUS ensures safer working practices and minimises the risk of service strikes by enabling our engineers and operatives to view buried networks virtually via smartphones,” he says.
MWS, like most utilities contractors, uses the Elgin database via roadworks.org to plan, map and execute streetworks. (Elgin, which describes itself as “the local and national communications hub for live and planned roadworks, road closures and traffic disruptions”, started life as a Jacobs Engineering e-government project in 2004.)
“We use Elgin to work out what’s under the ground – it’s a vital tool that records all the permissions and permits to dig,” explains Carter. “Eurovia uses it too, and that’s how we started collaborating with them.”
Digging up a road with little or no confidence in your knowledge of what’s lurking beneath the surface is a constant challenge for contractors. Many schemes have been suggested for creating a central database of buried services, with the National Joint Utilities Group proposing a ‘national computerised streetworks register’ more than two decades ago.
It never happened, partly because the technology didn’t exist to enable it, but also because of the multiplicity of non-compatible data. “There have been three or four attempts in the past, but the problem was always how to take all those drawings – all at different scales, all in different formats – and stitch them together,” says Carter.
“We dig a million holes a year. We go and get a set of drawings to work from and some are great, some aren’t,” he says. “Some of them are 100 years old.”
Even recently the task of creating an accurate database has seemed too complex. “We looked at some tech five or six years ago but it just wasn’t accurate enough,” Carter explains. “GPS gave us an accuracy of plus or minus five or ten metres, which isn’t any good.”
Eurovia’s breakthrough was to combine new software with a normal mobile phone and a GNSS satellite navigation antenna to achieve mapping with a high degree of accuracy. As Carter explains: “The antenna just clips to the phone and you have an accurate surveying tool with accuracy to plus or minus five centimetres.”
On most sites the work must proceed using the data currently available which, as Carter says, can vary in terms of accuracy. Existing drawings can be synthesised and loaded into AVUS, which creates both plan and interactive 3D images.
But this data can then be either verified or amended by the AVUS system as the reality emerges during excavation, and then stored. In this way, an accurate map of the network of buried services can eventually be built up.
The AR software superimposes the stored visual data over the image viewed through the phone’s camera. “You look through your phone and the AR overlaps pipes and cables so it’s just like X-ray vision,” says Carter.
The AVUS system not only reduces the risk of striking hidden services, causing damage or injury, but also means that work can progress confidently and with speed, keeping disruption to the public to a minimum.
The initial trial application in Roehampton was an eye-opener for Carter. “The real wow-factor is the stuff that happens after you’ve done the job. Because of the accuracy of the AVUS system, you can video that job on your phone and create a proper point-cloud model – and that’s really powerful. The final stage is to video the job after reinstatement so you have a complete record.
“If you could do that on every job, you’d end up with an accurate, detailed 3D map of everything under the ground,” he adds.
Eurovia UK director of innovation, Yogesh Patel, says: “When we developed the AVUS technology, we always knew that it would make a big impact on the safety and success of planning and programming of works.
“We are excited to see the benefits of AR applied to the utilities sector – we all have a collective responsibility to manage our infrastructure safely and sustainably. AVUS is a step in the right direction towards this vision.”
“Credit where it’s due – Eurovia has done all the hard work,” concedes Carter, “but they’re happy for us to trial it in the utilities sector. Yogesh and me are wired the same way – we’re not in competition. They have their own applications: different clients, same purpose.”