Joint research with the University's Institute of Marine Studies has been in progress for several years on a number of marine applications for composites. Tim Searle has been working on the design and manufacture of propellers since 1992. He has optimised RTM to produce a range of propeller shapes and sizes in glass/epoxy, many of which have been tested at sea on the University's workboats.
In addition to the obvious advantages of light weight and freedom from corrosion, composite propellers behave very different from metals under impact. Damage is localised, and the integrity of the shaft and gearbox is not compromised - this is often not the case with metal propellers.
Measurements have shown that the composite propellers are sufficiently stiff to perform at least as well as their metal equivalent in bollard pull, speed and open water efficiency. Work is now in progress to evaluate the long term properties of composites in a marine environment, and to exploit the anisotropic properties of composites to increase efficiency.
The picture right shows a 500 mm diameter GRP propeller installed on Pandora.