Rotary drives & gearboxes

A lot of offshore and industrial equipment comes down to one problem: putting controlled rotation, or controlled linear force, exactly where it’s needed. We design the rotary and motion drives that do it, matching motor, gearing, bearing and control to the duty so the machine delivers the torque and speed the job demands, reliably, in a marine environment. Whether the answer is hydraulic, electric or a hydrostatic arrangement. We engineer the whole drivetrain as one accountable assembly rather than bolting parts together and hoping.

Our power swivels and rotary drives are designed for drilling and pile rotation across the board – geotechnical drilling, pile-top drilling and pile rotation, and large-diameter drilling. They share a defining feature: a large-diameter open central bore through the rotation, so drill string, casing, wireline, tooling or fluid can pass straight through the drive while it turns. That open bore is what lets one rotary head serve a small geotechnical string or a multi-metre monopile, the torque and bore are sized to the job, the principle stays the same.

What we design

• Power swivels & rotary heads – the rotating drive at the top of a drill string or tool, passing torque (and often fluid) into the rotation while carrying the load.
• Rotators & slew drives – controlled rotation for tooling, manipulators and deck equipment, sized for holding torque as well as turning torque.
• Winch & drum drives – the geared drive behind a winch or reeler, matched to line pull, line speed and braking duty (see winches).
• Hydrostatic drive arrangements – closed- or open-loop pump-and-motor drives where infinitely variable speed, high stall torque or precise control matters.
• Slew bearings & rotation mounts – the load-carrying rotation interface, selected and integrated for the combined axial, radial and moment loads.
• Rack-and-pinion linear drives – converting rotary drive into controlled, high-force linear travel – for jacking, feed, skidding and positioning duties.
• Gearbox assemblies – planetary, bevel and parallel-shaft reduction matched to the duty cycle, with the service factors a marine duty needs.

How we deliver it

We size the drive from the duty, torque, speed, load cycle, environment and control, select the motor, gearing and bearing to suit and engineer the housing, sealing and interfaces around them. We design the circuit and the structure together, manage manufacture through our specialist supplier network, then assemble, run and test the drive before it ships. New-build, like-for-like replacement or re-engineering a drive that isn’t performing, all under single-party accountability.

Parameter	Typical scope
Drive type	Hydraulic · electric · hydrostatic (pump-and-motor) – selected to the duty
Motion	Continuous rotation · indexed/slew · rack-and-pinion linear
Components	Power swivels · rotators · slew drives & bearings · winch/drum drives · gearboxes · rack-and-pinion sets
Engineered for	Defined torque, speed or a combination; marine service factors; controllability
Delivery	New-build · replacement · re-engineer existing; supply or design-only