Centre bow and wet-deck design for motion and load reductions in wave piercing catamarans at medium speed

ABSTRACT

For wave piercing catamarans, the centre bow length and tunnel clearance are important design factors for slamming, passenger comfort and deck diving. This experimental study determined the influence of centre bow (CB) and wet-deck geometry on their motions and loads at reduced speed using five configurations. A 2.5 m hydroelastic segmented catamaran model was tested in regular head seas in wave heights equivalent to 2.7 m, 4.0 m and 5.4 m at full scale. Higher wet-decks had higher vertical accelerations but reduced slamming loads. The greatest peak vertical CB loads ranged between 18–105% of the total hull weight. Regression models were obtained for the vertical loads and bending moments. A reduction of speed from 38 knots to 20 knots reduces the maximum slam loads by approximately 30% in regular waves. Considering both low and high speeds, the Short CB was found to be a consistent design for slamming reduction.

KEYWORDS:

• Wave-piercing catamaran
• hydroelastic segmented model
• centre bow
• relative motions
• slamming
• vertical bending moments

Acknowledgements

This work was undertaken in collaboration between the University of Tasmania, Revolution Design and International Catamarans Tasmania (INCAT) through the support of the Australian Research Council Linkage Grant number LP0883540. The work of Dr Jalal Rafie Shahraki in the development and production of the hydroelastic segmented model is also gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors .

Additional information

Funding

This work was supported by Australian Research Council [grant number LP0883540].