According to the company, the worldwide trenching industry's enthusiastic development of ever-heavier and more-expensive machines in order to generate sufficient pick penetration is now made obsolete by its new HRT technique. The performance of conventional chain-saw rock trenchers tends to be limited when cutting hard rock due to there being insufficient tractive power for the digging picks to adequately penetrate. This problem results in poor productivity, high running costs, and a high-vibration ride for the operator. Unlike conventional trenchers — where the rear-mounted digging boom is pulled onto the rock face — Mastenbroek's new design has a reciprocating boom with an endless, reverse-cutting, chain that is pushed into the bottom of the trench to create an undercut. The boom is then progressively raised to the top of the trench to excavate the desired depth and width. The HRT layout also only engages the lower part of the idler wheel, and this is said typically to result in a 60% reduction in the number of picks penetrating the rock at any one time, hence proportionally increasing the power per pick and the breakout force. Spoil is carried along the top of the digging chain, discharging onto a rear-mounted swing conveyor which places material to either side of the trench. The cutting process produces a much more granular material than a conventional trencher which has to grind the rock to a dust in order to carry it out of the trench, thus requiring significantly more horsepower. The machine is operated by radio control, enabling the operator to stand at any safe point around the machine and, once the correct depth of trench has been established, the complete cutting cycle is then fully automatic with only the steering functions for the operator to control. A range machines is now available, with capacities of up to 5m trench depth and 2m trench width.