KEMROC's chain cutters, bullhead cutters and cutter wheels cut trenches at full face rather than chipping at them, which the manufacturer says delivers up to four times the productivity of hydraulic breakers at noise levels of 75 to 80 decibels. In cities running utilities through existing fabric, the noise number matters as much as the rate.
Utility trenching in hard ground is one of the least efficient operations in civil engineering. The conventional tool is a hydraulic breaker on an excavator, which chips material away by impact while the machine swings side to side to widen the cut. It works, it is universally available, and it is slow, loud, hard on the carrier machine and imprecise about trench width — a problem when every extra centimetre of over-break has to be refilled with imported bedding material.
The German manufacturer KEMROC builds an alternative family of excavator attachments that cut rather than break. Its range covers chain cutters, double drum cutters, bullhead cutters and cutter wheels, and the operating principle across them is the same: carbide picks mounted on a rotating or circulating carrier remove material continuously at the full face of the cut, so the machine advances in a line rather than swinging.
The bullhead cutter uses twin motors driving a drum arrangement suited to trenching in medium to hard rock, with cutting widths starting around 600 millimetres and no upper limit on trench width where multiple passes are acceptable. The chain cutter uses a centrally driven chain to deliver a precise full-face cut in narrower widths, which is the geometry a cable or small-diameter services trench actually needs.
The manufacturer's headline claims are worth examining separately, because they matter for different reasons. Productivity is stated at up to four times that of a hydraulic breaker in comparable material. That number, like all such comparisons, depends heavily on rock type and on how much over-break the breaker method was producing. The more interesting figure is acoustic: KEMROC puts operating noise at 75 to 80 decibels, against the substantially higher levels and ground-borne vibration a breaker produces.
In an urban context that is not an environmental footnote; it is a scheduling input. Work near occupied residential and hospitality buildings is governed by permitted hours, and noise and vibration limits are what determine whether a crew can work at night, when a road can be closed, and how long a lane closure can be held. A method that halves the disruption profile can double the working window, and the working window is usually the constraint rather than the machine rate.
There is a second, quieter benefit that operators notice before accountants do. Breaking with a breaker loads the excavator's swing gear repeatedly in both directions, because widening a trench means slewing. Cutting at full face removes that motion, which reduces wear on the most expensive part of the carrier machine to repair. On a hired fleet that is somebody else's problem; on an owned fleet running continuously it is a maintenance line.
The relevance to Saudi Arabia is straightforward. Utility corridors, district cooling networks, power and fibre routes are being installed through existing city fabric in Riyadh, Jeddah and the Eastern Province at the same time as major road and rail packages proceed. Saudi Arabia awarded 18 projects worth more than SAR30.03 billion in May and the Saudi Contractors Authority recorded 25 projects worth over SAR29.5 billion in June, with infrastructure prominent in both. A meaningful share of that work is trenching through material that a breaker attacks slowly.
The equipment argument at Big 5 Construct Saudi's co-located Heavy Saudi Arabia event has broadly followed this logic: contractors are buying measurable operational outcomes rather than machine specifications. Faster completion, less rework, fewer breakdowns and lower manpower dependency are the terms in which purchases are being justified across the halls. An attachment that cuts a trench to width, keeps the neighbours' complaints below the threshold that stops work, and does less damage to the machine carrying it is a reasonable fit for that test — provided the material is actually rock. In soft and saturated ground the problem is a different one, and the answer is stabilisation rather than excavation.