In the late 1970s, Robert Clerk arrived in Edinburgh with his designs for a 'tri-link', high-efficiency, variable-swash, high-speed, hydraulic machine and also for a novel flywheel system. He refined these for incorporation in the full-scale Duck concept that was then being developed by theconsortium that was led by the University of Edinburgh and included Laings, Mertz & McLellan and SCOPA (Scottish Offshore Partnership).

Robert made a huge impression on those of us who were lucky enough to know and work with him. After his death Win Rampen wrote an appreciation: Robert "Cyclone" Clerk 1908-1993. The principal meeting-room at Artemis Intelligent Power is named after Robert.

Robert, photographed in 1985, whilst designing the prototype tri-link machine that was being built in the wave power group's workshop. Note the draughting machine with digital read-outs and the Hewlett Packard (reverse Polish) calculator. No PC.

Details from Roberts drawings of the tri-link machine. The kinematic arrangements of all of the parts made the machine very light in weight. Larger motor-versions of this machine would be used to drive the Ducks' gyro flywheels and the generators.

Mattew Rea and Carn Gibson built and tested Robert's machine. In the photo on the left, Matthew is shown with most of the parts. The name 'tri-link' refers to the torsionally stiff, but otherwise compliant, arrangement of three sets of spherically jointed links that join the ring that he is touching to the shaft.

Robert's flywheel concept being tested. Elements of the flywheel are spun or pressed from thin mild steel sheet. The shallow conical shape resembles that of a musical cymbal. Two opposing stacks of such discs are pre-compressed against each other on the shaft. The artists's impression of the duck shows the flywheels in cut-away close-up at top left.