BMT Nigel Gee, a subsidiary of the BMT Group, is pleased to announce its association with sailing yacht Hemisphere, the 44m VPLP design catamaran recently launched from Pendennis Shipyard, making her world debut at the 2011 Monaco Yacht Show. Luxury catamaran HEMISPHERE is the largest sailing catamaran in the world measuring 44m (145ft). Her huge size and quality build make her incredibly spacious and luxurious. The Hemisphere yacht can sail or motor at high speeds and being a catamaran she is also very stable at sea. S/Y HEMISPHERE has 8 crew and can accommodate up to 12 charter guests in luxury in 4 double and 1 twin cabin.

Luxury superyacht catamaran Hemisphere - Courtesy of Pendennis Shipyard

BMT Nigel Gee was initially contracted to undertake full structural design and analysis of the superyacht Hemisphere by direct calculation. Definition of global load cases and subsequent analysis was undertaken with extensive use of Finite Element Analysis (FEA) used to analyse both stress and deflection from both global loads and high localised loads at the mast base and rig attachments.

Catamaran Hemisphere FEA

The structural design and engineering of the charter yacht Hemisphere have pushed the boundaries of classification society rules.  BMT worked closely with the vessel’s classification society during the development of a new set of rules for the structural design of vessels of this type and size which subsequently became BV Yacht Rules.

Sailing yacht Hemisphere Detail Design

BMT delivered a full Class Level Design, ultimately leading to provision of a comprehensive detailed production engineering package. Utilising ARL ShipConstructor for the development of the structure and pipe work systems, BMT provided full CNC cutting files and pipe spools as well as extensive engineering for the yachts complex outfit items.

Part of BMT Nigel Gee’s detailed design contract was to provide weight guarantees for the structure of the yacht. On the completion of each structural unit, weighed weights were returned from the yard and compared with both the early engineering estimates which formed the basis of the guarantee, and the detailed 3d structural production model from which the CNC cut parts were developed. These figures have shown that the yachts structure was delivered 6% below the contracted structural weight estimate.

World’s Largest Sailing Catamaran Hemisphere engineered by BMT Nigel Gee - Courtesy of Pendennis Shipyard

James Roy, Yacht Design Director at BMT Nigel Gee comments, “It has been a real pleasure to work on Hemisphere and the tenacity of her skipper Gavin Bladen is highly commendable. Through this project we have developed further our relationship with the VPLP office and collaborated on even larger ground breaking designs for sailing catamarans up to nearly 80m.”

BMT Nigel Gee has designed and engineered some of the world’s largest and most complex catamarans, including the 80m Sea Fighter for the US Navy, a 55 knots Gas Turbine powered naval vessel.