Static pressure tests on sections of yacht hulls, manufactured to copy
the structure of certain yachts which failed in service due to slammi
ng loads, are reported. The materials of construction were aluminum, s
teel, plywood and fiberglass. The failure modes and pressures are disc
ussed. In addition, some tests in which mild steel plates, correspondi
ng in construction to the mild steel hull tested under static pressure
, were loaded impulsively by the shock wave from an explosive charge d
etonated in air. The design of hull plating should take into account t
he impulsive nature of the loading, and the actual mode of failure. Ne
ither the design impulse, however, nor the means for predicting the hu
ll plating response to it are available from the current literature. I
f resort is to be made to the design of plating for simple static pres
sure, then a design pressure of at least 350 kPa (51 psi) is suggested
for the bottom plating of yachts of about 13 m (43 ft) length overall
. This is about five times the pressure required by the ABS Guide.