Requirements

During storms in February 2014, a section of coastal railway in Dawlish collapsed as a result of coastal erosion. A new sea defence wall is now required further along the coast to prevent another occurrence.

BAM Nuttall Ltd approached KM to solve a problem. The problem being, cuts up to 1.5m deep were required through existing concrete footings and natural sandstone rock to form a new trench for sea wall foundations.

Several options were weighed up including track sawing and rock sawing.

Due to the close proximity of the existing wall, it was determined a rock saw wouldn’t get close enough. As the material being cut was rough and wouldn’t support the anchors required for track sawing, KM Management set about plans to fabricate a plate that would mount to the quick hitch of our 8.5 tonne Hitachi excavator.

Not only would this proposal solve the issue of track sawing, it’d also speed up the process as there’s little to know set-up time – speed is of the essence on this project due to tides.

Plans were drawn up and the plate was fabricated. The track was mounted to the plate and tests were carried in-house.

Cuts up to 1.5m deep were required, however even the most advance track saws can only cut 1m deep. To counter this, we proposed to cut the trench to 1m deep, from there excavators would dig the trench out to 1m. The track saw rig could be lowered into the trench where a further 500mm depth could be achieved using flush cutting techniques – solving the problem of cutting 1.5m deep.

This was all met with the approval from our client and Network Rail.