Island innovation

Ship & Boat International: eNews December 2018

Australian ferry operator Sealink Travel Group is set to boost its fleet with a new 45m double-ended, aluminium ro-pax vessel, designed by compatriot naval architect Incat Crowther.

The forthcoming 150-pax ferry will be built by Richardson Devine Marine in Hobart, Tasmania and is scheduled to enter service in December 2019 (see Technical Particulars, below). Following handover, she will provide short-hop journeys between the port of Kettering, on the Tasmanian mainland, and nearby Bruny Island – an increasingly popular destination for day-trips. Incat Crowther tells Ship & Boat International: “The journey is a mere 1.5nm – so, at 12knots, it is over in less than 10 minutes.”

Consequently, much attention has been paid to optimising the ferry’s manoeuvrability, to ensure swift and efficient turnaround times. She will be fitted with four Scania DI13 070M main engines, rated 184kW apiece, which will be positioned in each of the vessel’s four corners, directly coupled to Schottel SRP 100 azimuthing drives. This configuration is also intended to grant the operator a high degree of propulsion efficiency: for instance, all four drives can deliver thrust in the direction of vessel travel, for extra kick. Incat Crowther adds: “If required, the vessel can operate on two pods during off-peak periods, reducing operating costs.”

For this project, Incat Crowther opted for an aluminium catamaran, rather than a steel monohull, form – a choice, Incat concedes, that is relatively “unusual” for a double-ended vehicle ferry. However, in doing so, the designer believes it has managed to realise a significant weight saving of 70-80tonnes compared to a steel monohull of equivalent capacity and performance.

An elevated cabin will be situated on the port side, offering a combination of fully enclosed and open-sided covered space: the indoor segment will provide seats with tables for up to 36 passengers, while the open-sided section will offer “café-style seating” for an additional 30 passengers. Given the vessel’s brief journey times, there was no need to install kiosk or bar facilities, though this area will host some power outlets and TV screens for the convenience of the passengers.

The ferry’s vehicle deck will boast four lanes: three of these will be unrestricted in height, while the fourth lane, beneath the elevated cabin, will offer structural clearance of 2.1m – “though a margin may be added to this for an operational limit”, Incat Crowther states. The central two lanes can accommodate a total 90 lane metres of trucks. Interestingly, the designer has also factored in a contingency plan for the ferry cat, should Sealink experience an upturn in demand for vehicle capacity. Rather than being designed to initially carry “surplus displacement until market demand warrants it”, Incat Crowther has developed the vessel to permit installation of a second vehicle deck at a later date. The company explains: “The second deck would be fitted above the open vehicle lanes, next to the elevated cabin. The upper deck will be hinged at amidships, where structure will allow for it: structural and performance calculations have already been carried out to accommodate it.”

TECHNICAL PARTICULARS

45m ro-pax catamaran ferry