Use of springs to simulate the wind induced moments on turret moored vessels

Abstract

This paper presents the results of an experimental study investigating the behaviour of a system of springs used to simulate wind-induced loading effects on turret moored vessels. These vessel types are extensively used offshore for hydrocarbon storage and production with model testing commonly performed at the design stage to gauge the influence of the environment on the vessel motion responses. The performance of the spring system is evaluated using a model vessel in a square complex wave basin over a range of long crested sea states represented by JONSWAP wave spectra and for two turret positions along the vessel longitudinal centre line. The measurements are compared with results from tests using conventional wind fans. It is shown that the spring design may be used as a mechanism during preliminary model testing to simulate the influence of wind on the yawing.