​We built the first rock saw, also known as the RockSaw, back in 2017.

The RockSaw consists of a carriage with flushing nozzles and a hydraulically adjustable blade on which a chain runs, which is driven by two Hägglunds hydraulic motors. Two hydraulic power units are required to operate the motors, each of which must be powered by an approx. 1000 hp diesel engine each.

The RockSaw is used where a vertical injector is no longer sufficient because there are rocks (such as granite or basalt) in the seabed. The RockSaw can be used for compressive strengths of up to 16,000 PSI (in comparison: flushing sword up to 6,000 PSI). Use at higher strengths is theoretically possible, but uneconomical due to the low working speed.

Using GPS data, the cable is then laid in the milled trench with a vertical injector.