Bruce Kirby, On Designing his Mk 1

In a series of emails and a phone conversation, Bruce Kirby related the story behind his first sailboat design, his International 14 Mk 1:

• In 1957, his friend, Roger Hewson, built a one-off fiberglass International 14 “Imagination” to his own design. (Roger, being an engineer with a degree from McGill, also built his own mast and sails). Before he designed and built his design, Roger and Bruce took the lines off Roger’s 1951 Bourke and Graeme Hayward’s Fairey Marine Mk 7 (Uffa Fox) . Roger developed a crude device to take sections from the hull made of pieces of ¼” ply, about 4” long by 1 ½” wide. These pieces were chained together with short bolts and butterfly nuts and the whole length was draped over the hull,and the nuts were tightened down. The now curved jointed plywood piece with the section shape was taken off the hull and the section shape was drawn on a sheet of plywood, then the lines were scaled down and transferred to paper.
• Roger’s 14 design “Imagination” ran hot and cold. Roger kept recutting his sails. Bruce feels that the Roger’s hull was pretty good; there was just so many different ideas being tried out at the same time that it was difficult to pin down the problems.
• Bruce came back from 1958 World Championship Team Races and POW in Cowes determined to design a faster hull upwind in a breeze. The Canadians were quick in the light stuff (they did win the Team Race that year) but were badly outclassed by the Kiwis (Geoff Smale and Ralph Roberts sailing his modified Windsprite “Atua Hau”) in any breeze over 10 knots.
• Bruce designed the Mk 1 over the winter of 1958-1959. The Mk 1 was built in Lachine, near Montreal by Bob Harris (Bob, an Aussie, was a close friend who designed and built catamarans nearby). Before the first one was finished (Bruce’s own 14), three others had ordered Mk I hulls. One was George Cook, Royal Navy Undersea Demolition Frog Man in World Wat II and also a dinghy designer for a few years after the war, a fine sailor and old friend of Bruce's. Bruce can't recollect the other two, though one was from Pointe Claire Yacht Club near Montreal. Bruce Kirby’s Mk 1 was actually launched in early summer of 1959 and won it’s first race. When Roger Hewson saw the Mk 1 in the flesh he said his ‘Imagination’ design was the thin one and Bruce’s Mk 1 was the fat one. In the Mk 1, Bruce fined up the underwater sections in the bow but still flared the gunwhale shape full up forward to prevent nosediving downwind.
• Compared to the Uffa designs at that time, Bruce feels the Mk 1 was definitely faster upwind and downwind in a breeze but was slower in borderline planing conditions (too much wetted surface in the wider aft sections). Graeme Hayward, sailing his Uffa design was particularly fast off the wind.
• Two of the Kirby Mk 1’s, Bruce’s and Ward McKim’s, were on the Canadian team in 1961 that won the World 14 team racing championships held at Toronto.