Power Trimaran superyacht becomes a reality

by Orion Shuttleworth on 2 Jul 2011

Superyacht Adastra under construction in McConaghy yard Zhuhai China SW

Motor yacht Adastra is a very interesting superyacht which is designed for ultra efficient long range cruising. The striking 42.5m Trimaran Adastra was designed by John Shuttleworth Yacht Designs and is currently being built in China by McConaghy International for a Hong Kong yacht owners Anto and Elaine Marden.

Superyacht Adastra profile in silver a 42.5m Power Trimaran - Designed by John Shuttleworth Yacht Design © SW

Yacht 'Adastra' is the result of more than five years of design and discussion with the owners, to build a yacht that meets the needs of a very experienced ocean voyaging couple and their family, and to provide the level of comfort and style that would be expected in a yacht of this class and size. No effort has been spared in the challenge to produce a beautiful yacht that will have low fuel consumption and yet provide excellent sea keeping qualities and luxurious accommodation.

Yacht 'Adastra' takes the power trimaran concept further than has ever been attempted before, previous vessels like 'Earthrace' and 'Cable and Wireless' were stripped out record breaking machines. The challenge of turning this concept into a viable luxury yacht has led us to further research and to develop new thinking on stability and comfort at sea for this type of craft.

Extensive tank testing and radio controlled model tests in waves have been carried out to analyze stability and performance. Outrigger height has been optimized for ease of motion at sea, and a new outrigger shape has been developed to increase stability in waves. We have undertaken a state of the art structural analysis of all the major components in the yacht in order to achieve the light weight required for very low fuel consumption. All this has resulted in the exceptional vessel that is nearing completion in China.

Superyacht Adastra a 42.5m Power Trimaran - Interior Saloon and dining © Jepsen Designs Hong Kong © SW

Adastra’s 16 metre beam creates a spacious saloon area on the main deck which offers superb views through a panoramic window and accommodates a lounge area, dining table, and navigation station. A forward facing door through the saloon window gives easy access to a large sunbed on the foredeck. The aft deck has a sofa and bar area to port and a dining area to starboard, further aft of this there is space for a 4.9 metre tender and directly below is a garage which can store a 3.1 metre tender. The garage door has been designed to fold out and create a large dive platform.

Superyacht Adastra cockpit in silver a Power Trimaran - as Designed by John Shuttleworth Yacht Design © SW

Extra space has been created below deck by slightly flaring the central hull just above the waterline. This area has been split into two sections with a full-width master cabin located aft with access from the deck saloon, and two further guest cabins, accommodation for the crew, and the galley located forward of the engine compartment. Adastra offers comfortable accommodation for nine guests and up to six crew members. The main helm station, which has seating for two, is positioned in a raised pilot house situated between the aft deck and the saloon area and forms part of the cross beam structure.

Superyacht Adastra aft a Power Trimaran - as Designed by John Shuttleworth Yacht Design © SW

The Superstructure is carbon fibre with Nomex honeycomb core, the hull is Glass/Kevlar foam sandwich and the interior is light weight oak cabinetry using honeycomb panels. To help reduce weight, virtually every aspect of the boat is custom built. This includes carbon fibre hatches, portlights, ladders and even hinges, which are all built specifically for the vessel.

A SiMON_ integrated ships monitoring system monitors fuel, security, pump sensors, electrical, lights, etc. The vessel has a fully automated fuel management system which includes an Alfa Laval system for cleaning the fuel.

The anchoring system is unique with three anchors all driven by carbon fibre drum winches run by hydraulics. The primary anchor is a custom 130kg Bruce style anchor that deploys out of the starboard wing. The second anchor is 80kg and deploys out of the bow with a carbon fibre arm. The third anchor is 60kg which deploys out of the port wing and will be used as a stern anchor.

Specification of Motor yacht Adastra:
LOA – 42.5 m
Beam – 16 m
Hull Draft – 1.12 m (1.6m to tip of rudder)
Main engine – 1x Caterpillar C18 -1150 hp @ 2300 rpm
Outrigger engines – 2x Yanmar 110hp @ 3200 rpm
Generators – 2 x 36 kw custom in the outriggers linked to 110 Hp Yanmar engines, and 1x 26 kw Northern lights in Main engine room
Owner and Guests – 9
Crew – 5-6
Tenders – 4.9m stored on the aft deck and a 3.1m stored in the garage
Freshwater Capacity – 2x 800 gph fresh water makers – 2700 litres water
Displacement light – Fully equipped and full stores and crew, no fuel and no water – 49 tonnes
Displacement cruising max – (normal operational load) 15000 litres fuel – 64.8 tonnes
Displacement ocean passage max – (only for occasional long ocean passages) 32000 litres fuel – 77 tonnes
Speed max – 22.5 knots
Range at 17 knots – 4000 miles
Fuel consumption at 13 knots – 90 litres per hour.
Fuel consumption at 17 knots – 120 litres per hour
Exterior Styling – John Shuttleworth Yacht Designs Ltd.
Naval Architecture – John Shuttleworth Yacht Designs Ltd.
Structural Design – John Shuttleworth Yacht Designs Ltd. & Applied Structural Analysis Ltd.
Interior Design – Jepsen Designs, Hong Kong
Builder – McConaghy Boats, Zhuhai, China

Please contact John Shuttleworth Yacht Designs Ltd for more information:
Springhead
Clay Lane
Cootham
West Sussex RH20 4HL
England
Tel +44 (0)7880 796 862 or email John and Orion Shuttleworth at orionshuttleworth@yahoo.com.