Trimaran - Comparison To Monohulls

Comparison To Monohulls

Two types of trimaran exist: the regular trimaran and the open trimaran, which features a trampoline between the hulls instead of plating.

Trimarans have a number of advantages over comparable monohulls (conventional, single-hulled sailboats). Given two boats of the same length, the trimaran has a shallower draft, a wider beam, less wetted area, and is able to fly more sail area. In addition, because of the righting moment provided by the wide beam, trimarans do not need the weighted keel that is required in monohulls, often resulting in unsinkable designs. As a result of the wide beam, the trimaran offers much better straight-line performance than a monohull, is able to sail in shallower water, and maintains its stability in stronger winds. However, its wider beam requires more space to maneuver, so tacking and gybing can be trickier in confined areas and the narrower hulls provide less living space than an equivalently-sized monohull. Trimarans also require more docking space in marinas, unless the ama can be folded to reduce the beam.

As the righting moment (the force that resists the opposite torque of the wind on the sails) is produced by a float on either side called an ama and not a heavy protruding keel, trimarans are lighter and faster than a monohull of equivalent length. A lightweight retractable keel or foil, referred to as a centerboard or Daggerboard is often employed to resist lateral movement, making many models easily beachable. Most trimarans are difficult to flip sideways given a reasonable degree of caution, however, trimarans can reach speeds so great in high winds that they can plow into the back of a wave and flip end-over-end (Pitchpole). This hazard is especially dangerous for a multihull that is using a spinnaker in high winds and large seas. To avoid this unfortunate scenario trimaran sailors are advised to reduce sail and to always have all sails easily released. The use of trampolines with a large weave, to allow water to easily pass through, and the deployment of parachute anchors drogues and sea anchors whenever appropriate should reduce the risk to an acceptable degree.

The father of the modern sailing trimaran is Victor Tchetchet, a Russian émigré and a strong proponent of multihull sailing. Mr. Tchetchet, who was a fighter pilot during the First World War in the Czar’s Air Force, lived in Great Neck, New York from the 1940s until his death. He built two trimarans while living in the US, Eggnog 1 and 2. Both boats were made of marine plywood and were about 24 feet long. Mr. Tchetchet is credited with coining the name trimaran. Aside from boat design Mr. Tchetchet earned his living as a landscape and portrait painter. About the same time, Arthur Piver was also building trimarans in the USA and created many early plywood designs to which amateurs built their boats. Many successfully crossed oceans despite being relatively heavy and inferior compared to those of more modern design. The homebuilt cruiser movement survived his death in 1968, with designers Jim Brown, John Marples, Jay Kantola, Chris White, Norman Cross and Richard Newick bringing the trimaran cruiser to new levels of performance and safety.