How Dubois and Alloy Yachts created Drumbeat

A length dictated by the crew cabins

The initial design, in 1999, called for a yacht of around 44 metres. It grew to 50 metres to fit everything in, then gained three more for the crew quarters, lazarette and forepeak. Ed Dubois set it out in his design brief: the number of crew cabins dictated the length.

The specification called for six crew cabins with en-suite bathrooms, each able to sleep two. The usual crew was nine. The brief also called for a spacious crew mess. The fifth cabin was delivered as a gym. It could be converted into a cabin.

Dubois Naval Architects described her as its most ambitious sailing yacht project to date and the largest sailing yacht the practice had designed. Alloy Yachts won the tender the same year. During the build, the Henderson yard, near Auckland, employed 240 people. According to the construction log, almost all of them were sailors.

Everything on one level

The helm station was placed on the flybridge. Cockpit, saloon, dining area and navigation station could then share a single level. Ed Dubois considered the layout unique at the time and believed it required at least 37 metres.

The decision to use a ketch came early in the design process. It could carry a mizzen staysail and a great deal of sail downwind. The broad foredeck provided space to carry the gennakers and mizzen sails. Marten Spars built the carbon masts and furling booms. Carbon was chosen for its strength and low weight, which helped keep the centre of gravity low when the sail area was reduced.

The Warsash tank and the Auckland wind tunnel

The hull was tank-tested at Warsash, a facility attached to the University of Southampton. Several keel configurations were studied to balance stability with access to most harbours able to accommodate a 50-metre yacht.

The sail plan was studied in Auckland. A 1:31 scale model was tested in the University of Auckland's wind tunnel, commissioned in 1994 with Team New Zealand and North Sails NZ to prepare for the 1995 America's Cup. Burns Fallow, head of North Sails NZ and sailmaker to Team New Zealand, led the study. It showed that the mizzen staysail raised total forces by about 20 per cent.

A full-size mock-up

Alloy used a full-size mock-up to develop the cockpit, flybridge, saloon and cabins. The galley was also reproduced at full size to suit the chef.

The yard designed and built thirteen captive winches for the yacht. The construction log records 100 kilometres of cabling on board. Her bulb keel holds 91 tonnes of lead. Yachting magazine estimated that the build took around 400,000 hours of work.

New Zealand's largest pleasure yacht

She was launched at Henderson at the end of 2001 under the name Salperton and delivered early in 2002. She was then the largest pleasure yacht ever built in New Zealand. She also took Alloy Yachts beyond 50 metres for the first time.

On 2 October 2002, New Zealand Post issued a two-dollar stamp featuring Salperton, in its Leading the Waves series.

By the spring of 2005 she was sailing as Drumbeat. Under that name she entered the Rolex Transatlantic Challenge.