Topcon improves accuracy on historic London building redevelopment

When embarking on a development project that will see the creation of more than 70 luxury apartments in London, the JRL Group turned to Topcon Positioning GB to provide a complete end-to-end workflow solution.

First started in 2016, the project is the £175 million reconstruction of a building constructed in line with surrounding Grade 1 listed architecture in Central London, Regents Crescent. After being damaged during the war, the residential building was temporarily rebuilt, however it has since been flattened and is now being rebuilt in line with the original specifications to ensure the new building is in keeping with the surrounding architecture.

The team was working within the confines of relatively small, indoor spaces during the initial planning stages of the project, so needed a technology that allowed each point to be laid out within an extremely tight tolerance of 2mm — compared to a more typical allowance of 10mm. The shape of each apartment also added an extra layer of complexity for the team. Each room used three separate grid systems, with one taking an arch shape to match the original designs of the building, making it difficult for the team to set out gridlines.

To help overcome this, the JRL Group used Topcon GT robotic total stations. The GT series offer users a high-performance solution that provides the efficiency of a single-operator robotic system and the power of long-range reflectorless measurements. The GT robotic total stations are also a third smaller than others in size, making them ideal for use in the confined working areas.

“We selected Topcon as a one-stop solution to set out and produce as-builts,” explains Trevor Homes, construction survey manager at JRL Group. “The field controller set up is completely intuitive — we had an intern working on the Regents Crescent project and within a day she was up and running, setting out in applications.”

The Topcon MAGNET field controller was used alongside the GT robotic total stations, to control and verify the points set out during the initial phase of the project. The controllers offer a full range of connectivity and instruction options, allowing JRL Group to control job file layers and select different options, such as the circle centres of line intersections, remotely.

Throughout the project, JRL Group used Topcon MAGNET Field software — a user interface designed to work with the Topcon positioning tools. All setting out tasks can be performed from within the map screen to give the team full visual context with interactive drawings. The Wi-Fi or cellular connection allows the site and office teams to get a full picture of the project at all times and in real-time; helping to keep the teams connected.

Trevor continued: “Topcon’s MAGNET Office has been great for our reporting, particularly on the levelness of the concrete floor. The technology has a great CAD package and we’ve been able to pull reports in just 15 minutes, so it’s really helped us save time on-site.”

Simon Crowhen, national sales manager at Topcon Positioning (GB) Ltd, added: “This is a fantastic example of how using complete workflow solutions can truly save time and money for teams. It would have taken JRL Group two hours to create the plans for the project using traditional methods, but they’ve been able to finalise them in just 15 minutes by using our technology.

“The work is still ongoing at Regent’s Crescent and we’re working closely with JRL Group to provide complete workflows, with more technology being adopted as the project continues. By using these end-to-end solutions, JRL Group is increasing productivity, saving time on-site and improving the accuracy of the works taking place.”

Trevor concluded: “Some of our group of 40 field engineers were resistant to change at first, but now they would be even more resistant if we tried to change away from Topcon! We’re now working to standardise all of our projects around a Topcon field-office software workflow.”

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