An initial programme to assess the effect of large excrescences on wave loading of circular cylindrical members has been completed. This involved the testing in waves of vertical cylinders fitted with rack teeth, and horizontal and vertical cylinders fitted with sacrificial anodes.

Results for both forms of excrescences suggest that high loads can be produced under certain conditions (up to 4 times those on a smooth cylinder, when rack teeth are fitted), notably when the excrescences were at large angles of incidence. Furthermore, these results would not have been predicted by existing methods.

Data obtained also show that the effect of excrescences is dependent on several parameters, only a few of which could be examined in this starter programme; a more thorough investigation is therefore recommended.