BMT has announced that its latest passenger ferry design, for Aran Island Ferries, successfully completed sea trials and has now been delivered.
The Saoirse Na Farraige is a 40 metre medium speed monohull ferry built to a BMT design by Cheoy Lee Shipyards in China.
Niall O'Brien, Director at Aran island Ferries, commented: “We are thrilled to welcome Ireland’s largest and most environmentally friendly domestic passenger ferry to the fleet. Designed by BMT, the vessel also provides maximum comfort in all weather conditions and, with additional space for our crew and passengers, Saoirse na Farraige will greatly enhance our overall travel experience and operation.”
BMT supported Aran Island Ferries from initial concept, through the tender process and finally developed the detailed production design with Cheoy Lee shipyard. BMT’s involvement throughout the project provided Aran Island Ferries with the design continuity necessary to reduce risk and ensure that the vessel fulfilled all their expectations.
The vessel is the largest domestic passenger ferry in Ireland with a capacity of 394 passengers, a footprint including a spacious main deck for 306 passengers divided into two seating areas that will provide comfort onboard, and a semi-covered space for 88 passengers on the top deck. The design also features a large wheelhouse with excellent all-round visibility, and a crew rest area with comfortable amenities.
Sylvain Julien, Director of Naval Architecture at BMT explains: “This design is part of a growing family of medium speed vessels designed by BMT that are based on high-speed craft design paradigms with the aim of significantly reducing fuel consumption and, more generally, operating cost.”
For a 40 metre vessel operating at 20 knots, a low displacement is key to achieving minimum installed power. To achieve this, the vessel was built out of aluminium while still providing a ruggedized platform suitable for operation in the Galway bay.
Sylvain Julien further comments: “Despite the constraints associated with the use of aluminium for vessels that do not fall under the IMO High Speed Craft [legislatory framework], this construction material significantly improves the through life cost of the vessel while reducing the day-to-day exhaust emissions thanks to reduced power requirements.”
To complement the lightweight design approach, a new double hard chine hull form was developed and optimised specifically for operation in the challenging environmental conditions experienced on the route. The semi displacement hull form provides both excellent hydrodynamic characteristics and a high level of comfort.
The propulsion system consists of two Caterpillar C32 (1081kw) diesel engines driving fixed pitch propellers which, together with the newly developed BMT hull form, enables the vessel to hit speeds in excess of 20 knots.
BMT is committed to leading the way in designing vessels that lower the environmental impact, and the company continues to work towards increased sustainability by leveraging alternative approaches to ferry design.
By Jake Frith