A1 Widening - Completing a 3D Machine Control Highways Journey

Since Giles Potter, MD of Potter Plant Hire started work on the A1 widening from Leeming to Barton, thousands of hours of Trimble® 3D machine controlled earthworks have been completed.

Once a 19.3 km stretch of dual carriageway, the section of the A1 has been transformed into a three-lane motorway, complete with a 15km local access road, nearing completion. For the A1M2 consortium, a joint venture between main contractors Carillion and Morgan Sindall, the project has been full of firsts, using a full range of technologies.

At its busiest, the project had up to 40 pieces of equipment in operation at any one time and boasted the largest and most integrated 3D enabled mixed fleet ever seen on a road job in England. Together with Trimble enabled A1M2 surveyors, the very latest in 3D Building Information Modeling (BIM) modelling techniques has been used on the job, to ensure complete traceability of the key earthworks stages of the project.

As the project now draws to a close, Finning News caught up with Giles to understand the impact the technology has had on the delivery of the new highway. Giles: “The task at hand was significant to say the least, with 1,600,000m3 of earthworks excavation and 1,570,000m3 of deposition spread across the site followed by the exacting placement of 1,000,000 tonnes of dry stone to form the base for 650,000 tonnes of pavement.

“Over the course of the project we used 3D machine control on Cat® dozers, graders and excavators and a range of other equipment to perform various tasks.

These included formation through to fine grading, of the road surface to a millimetre tolerance and grading of the banks and bunds. Aggregate Industries even used a Trimble 3D enabled asphalt paver to lay the road surface. “In total we clocked up thousands of hours of machine operation, including major loading and hauling operations, which was a staggering achievement. Throughout the works we collaborated with the A1L2B team, its surveyors and

Trimble dealer SITECH® UK & Ireland, to digitally document the whole project in a state-of-the-art BIM model.

“Because of this collaborative approach, we now have a much better understanding of how to plan and implement large-scale earthworks projects. I think the key lessons have been around the creation of a digital construction approach and mindset.

“Because the whole site used Trimble Business Centre and its Trimble Connected Community, each machine and surveyor operated Trimble rover, were able to feed information into the BIM model from anywhere on the site. This was achieved by using two base stations to cover the whole of the project.

“Because everything was done in real time, at the end of every day, we were able to see our progress against plan. This gave us forward insight to plan the arrival of equipment onto site, schedule works around harsh weather conditions and react immediately to 3D model changes.

“This was particularly important when it came to building up the millimetre accuracy of the sub-base layers of the new road, as compaction levels varied across the site, requiring more material in certain areas. From an earthworks perspective, this meant we were able to move material once and well, placing it much more efficiently.

“In-turn this led to less equipment movements and therefore a much safer site. In fact, the amount of people needed onsite was dramatically reduced, as there was no need for any pegging out or in-situ level checks. Plans were sent remotely to machines and data transmitted back to the office, using the GSM network. “I think for me what really simplified the project was the flexibility of being able to fit the Trimble system to so many different machines of different ages from different manufacturers. This allowed us to source the right products, at the right price, with the right capabilities to perform the tasks at hand.

“Getting machines fitted with the technology quickly was also important and that was where the support from SITECH field engineers real helped. Along with the technical support from its team at head office in Cannock, we were able to quickly configure units and have them operating onsite in a matter for days.

“In conclusion, I think that right from the start of the project, the digital construction approach really set a benchmark. By modeling earthworks in a BIM style model before work began, the A1L2B team identified where we could excavate and place material across the site.