The Borders Railway project is the re-commissioning of an abandoned railway line from Edinburgh to Tweedbank, Scotland. Project owner BAM Nuttall asked Mammoet to install four 107-ton concrete beams as part of a bridge over the busy Hardengreen roundabout.
For the operation, the roundabout was closed off to traffic over the weekend. With only 56 hours to complete the job, Mammoet applied the principle of less is more, mobilizing a single crane that could lift and install all four sections from one location. This effectively cut operation time in half compared to alternative methods.
Construction on the Hardengreen roundabout had begun seven months prior to the lifting operation and included the installation of the bridge piers the beams had to be lifted onto. The time window for the actual lifting was just 56 hours. After that, Monday morning traffic would arrive to take over the busy roundabout. This kind of time pressure meant that every hour saved during the operation was essential.
Mammoet’s solution was one of quality over quantity. By bringing in a single crane large enough to carry out all lifts from one position, overall operation time was cut in half. While other cranes with comparable lifting capacities needed 14 hours to be rigged, the LTM 11200-9.1 crane only needed six. A second major advantage of the single-crane approach was the simplification of the beam deliveries. Thanks to the crane’s vast reach, the beams could be delivered to the same pick-up point, saving precious time moving from one pick-up location to the next.
With the strict deadline of Monday morning rush hour, overshooting the production schedule was simply not an option. Mammoet’s time-saving solution got the job done with time to spare, giving the crew more room to breathe and more room for contingencies.
Having started on Friday evening, all beams were in place and the crane was dismantled by Sunday afternoon. Well in time for the first cars driving onto the roundabout the next morning and as if the bridge had always been there.