ONR studies high-speed planing hulls

The US Office of Naval Research (ONR) has sponsored work to look into the wave-generated pressure, forces and motions faced by boats with high-speed planing hulls, it announced on 27 May.

Planing hulls produce lift and allow watercraft to glide over water to achieve higher speeds; but high wave crests result in the boat rising to the top of the wave and then falling to the trough at great force, called a ‘wave slam’.

The research conducted by ONR aims at identifying ways to save weight on the hull in order to carry greater loads without sacrificing speed capabilities.

Bob Brizzolara, program officer, sea warfare and weapons department, ONR, said: ‘When a hull is going at speed and it hits a wave, it’s like hitting a wall - it’s a violent collision, and the forces are very large. This causes injuries to sailors - commonly back and leg injuries - and also can degrade the structure of the vessel.’

Carolyn Judge, associate professor, naval architecture and ocean engineering department, US Naval Academy (USNA), said: ‘To deal with the effects of wave slams, the navy must have strong boats that are forced to reduce speed in higher seas. Mitigating the problem of wave slams will allow navy boats to travel faster in higher seas states as well as allow for lighter boat structural designs.’

ONR is working with the University of Iowa and the USNA’s Naval Surface Warfare Center (NSWC), Carderock Division, to consider hull weight reduction options. The research is being executed by experimenting with scale models tested at NSWC Carderock’s tow tank and with computer simulations developed by the University of Iowa.