Packing power into a tight space – how to marine engineer a trimaran.

The benefits and constraints of the trimaran design are highlighted, and how these features impinge on the marine engineering design of the vessel is discussed. For the trimaran concept to be a success the marine engineering of the vessel must be considered from the outset of the design; the three long thin hulls of the vessel make it very sensitive to alterations in machinery fit. Trimarans are compared with monohulls: the overall length and beam of trimarans is greater, the extreme L/B ratio for the main hulls of the trimarans, 13.5 to 15.2 compared to the 5.1 to 8.3 for the monohulls, and the trimaran main hull beams are between 44% and 62% that of the monohulls. Distribution of the propulsion machinery in a trimaran can be split evenly between the side hulls, with nothing in the main hull, located in the main hull only, or divided between the main hull and the side hulls.