The K1 is now in full production with over 80 boats built. Below is a brief summary of the development process prior to production.
Initial prototype tests – Summer 2009
The prototype boat hull was CNC milled in polystyrene from CAD files before being reinforced where required and skinned with a thin epoxy glassfibre laminate. This provided a light hull suitable for testing.
The first test sailing was conducted on the Norfolk Broads over the summer in 2009 with an adapted Firefly rig to get a feel for performance and suitable sail area. A jib pole was added to create a simple self-tacking jib as used on model yachts and traditional Broads sailing boats.
Although the test rig was far from optimum, sailing the prototype quickly showed the great potential of the concept – gliding effortlessly across broads and up rivers, short tacking being a real joy.
The sail plan was finalised following this evaluation and the prototype spars and sails from Selden and Hyde were delivered shortly before the Southampton boat show in September 2009.
Prototype rig tests
Following the Southampton boat show, sail trials were conducted with the prototype carbon rig and Mylar sails.
The mast was a Selden S2 carbon mast which is light with low section diameter tapering to a very fine tip. Compared to the C-section alloy mast used for the first sailing trials the S2 was several kilos lighter, thinner and yet significantly stiffer.
The boom tested was also carbon to keep overall rig weight down and the jib pole alloy, but after testing this we changed to a carbon jib pole to reduce its weight to help the jib to goose-wing in light airs.
The Mylar sails from Hyde were also lighter than the Dacron sails used at first with the additional advantage that you can see through them. The jib was about 1 sqm larger than first tested to provide more area while keeping the centre of effort of the rig low.
Sail trails with the prototype rig were encouraging and further trials were conducted using a new slightly less stiff S2 mast on the moulded production hull early 2010.
Production moulding
The hull mould was produced from a CNC milled pattern with some small modifications to shape compared to the prototype hull. The deck mould retained the same cockpit shape as the prototype but with slightly wider side decks.
Prior to moulding the first hull and deck, Synthesize Yachts made up a series of test panels to establish the best laminate material specifications and resin to achieve light, stiff and strong mouldings using a resin infusion process. The test panels were examined and then tested at Southampton Solent University
The results were very encouraging and confirmed that the use of a special new lightweight infusion core material and Vinylester infusion resin would give very good results for the production of hull and deck mouldings.
The first moulded hull was on show at the 2010 London Boat Show on the Hyde sails stand. Careful attention was paid to selection and position of fittings to ensure that the boat had a very clean and efficient layout.
Development and sailing trials continued in early 2010 alongside the first trial sails. The first production boats were moulded on completion of the rig and fit-out development process and then Synthesize built 50 K1’s over the next 20 months. Rondar Raceboats took over production in January 2012 and have already made over 20 more K1’s. The core material used in the hull and deck laminate is now 5mm foam which is vacuum consolidated to give the best strength and stiffness to weight ratio.