Introduction

The Pelamis ‘sea-snake’, developed by Ocean Power Delivery (OPD), works as the tubular elements pass over the surface of the waves, the flexing of the joints between them activating hydraulic rams and generating electricity.

Pelamis is the first such machine to be used in a commercial wave energy farm, and is due to come into service off the coast of Portugal during 2007. Frazer-Nash Consultancy was brought in by OPD to carry out a reliability analysis of Pelamis.

Reliability Assessment

As the design of the production variant progressed, OPD wanted to optimise the reliability of Pelamis. They called in Frazer-Nash because of our experience and reputation in reliability engineering, especially in relation to the harsh marine environment.

We produced a detailed reliability model of the device, allowing the sensitivity of the overall reliability and availability to individual component failures to be evaluated.

Benefits

The work carried out improved the overall reliability of Pelamis as well as pointing the way towards a refined maintenance strategy and advising on further design improvements that could be made to the concept.

This is expected to maximise the availability of the production device, and minimise the cost of intervention and repairs, allowing Pelamis to run at the highest possible continuous rating.