In July 2024, Brownline surveyed two directional drills in England. Near Milton Keynes, our client FlowTek HDD, commissioned by Rogers Civil Engineering, drilled under the M1 motorway twice. These two bores were designed to be only 2.5 m / 8 ft apart!
Near the junction with the A509, the motorway was crossed. This meant that with the on- and off-ramps included, a total of 12 lanes were crossed. The bores had a length of 250 m / 820 ft.
2.5 m / 8 ft spacing between bores
The centre-to-centre distance between the two pilot bores was 3 m / 10 ft, which meant that after reaming, the bores were only 2.5 m / 8 ft apart. It was therefore very important that the pilot bores were carried out the the highest accuracy.
That is why the crossings were surveyed using the Drillguide Gyro Steering Tool. This is the most accurate gyro in the world and that makes it the ideal solution for a trenchless project like this. That is because the Drillguide GST can make the most accurate measurements under all circumstances, without the need for surface access and without being disturbed by surrounding infrastructure.
Through these HDD crossings, two electric ducts were installed as part of a major development project. The crossings under the M1 were the most important of the entire project. Brownline is proud of its contribution to this project, which ensured that the pilot bores for these crucial connections were carried out as efficiently as possible.