Case Study - Screaton & Associates

‘Nereus’ Flying Sheave In Line Compensator

Scope of Supply

X-Wave Active Heave Compensation Control System, MRU, Datalogger, Machine PLC Control & Safety System, Deck Control Console & Vessel Integration.


To add cost effective Heave Compensation to an existing Launch & Recovery System (LARS) without having to modify the existing Winch.


15Te SWL, +/-3m (6m) heave amplitude in 8s period, hydraulic cylinder synchronisation error better than +/-2.5mm (5mm).

Commissioning the Nereus Flying Sheave In Line Compensator after mobilisation on the vessel.

To further reduce costs, the machine was designed to utilise and interface to the existing LARS HPU, which provided hydraulic power to the system at 250Bar, 550l/m.

Services Provided

Detailed engineering including software design, control system design, control panel & deck console build, installation, commissioning & mobilisation.


10 weeks from order to completion of FAT and delivery.


Delivered on time and budget with Successful seatrials completed without attendance of any commissioning personnel. Auto tuning and adaptation/self-learning successful, hydraulic cylinder synchronisation better that 1mm achieved at maximum velocity.

Universal – multi-axis positional control for all offshore active heave compensation applications

Active heave compensation of ROV, AUV & Trencher LARS; Subsea Cranes; Lift Winches and Deep Water Lowering Systems; Well Intervention Systems; IMR Systems; IWOC Systems, Drill String Compensators; Flying Sheave Compensators and Survey Equipment. Stabilisation of Lifting, Helideck and Antenna Platforms; Walk to Work and Personnel Access Systems. Add cost effective accurate motion compensation to your offshore equipment with X-Wave™ 'Out of the Box' Advanced Universal Motion Compensation System