The 48 metre square Rolling Platform was built to recreate a ships deck ‘pitch and roll’ during sea trials. The specification was to achieve movement of plus/minus 15º in simple harmonic motion over a time of 8-seconds. The computer controlled system allows the platform to follow a random wave pattern collected from a ships telemetry system and able to recreate 7 pre-set sea conditions. Hedley supplied the hydraulic and electrical control systems including a 165-kW HPU, supplying a flow of 625-lpm up to 210-bar. Control of the platform is by one hydraulic cylinder commanded by a Parker 6-port proportional valve.