other words, it’s complicated in concept but simple in execution. Baltic prides itself in developing smart solutions for client ideas and the genoa sheeting is just that. Fingertip sail trimming from the cockpit with a triple-headed sailplan to manage created some
complexities for a short-handed crew. For optimum sailing performance the ability to trim headsails in three dimensions – athwartships, fore and aft and vertically at the clew – is critical. Previously this would have been managed by a series of complicated barber-haulers, inhaulers and tackles requiring fiddly hardware and considerable manpower and, fatally, aesthetic compromise. Under the foredeck of the Baltic 112 are four Harken hydraulic rams lying fore and aft on the centreline. One is used to operate the backstay deflector while the other three control a three-part bridle attached to a central ring through which the headsail sheet is led. Instead of having to tweak separate haulers and tackles to alter the trim of the sail, which may involve a crewman going forward to make the adjustment, everything can be done from aft at the touch of a button. Co-skipper John Walker says: ‘Our aim was to have full control from the back of the boat, eliminating the need for tweakers and inhaulers. There are many ways to trim a sheet and you could do this with athwartships tracks, but I think we
have a lightweight option that ticks all the boxes and looks good.’ Working in conjunction with this is a 350bar hydraulic system providing higher pressure to serve the many hydraulic functions on the yacht. Apart from the trimming system, they include three furlers, boom vang, mainsail cunningham, numerous mast winches, primary winches, secondaries, the anchor windlass, transom door, the RPS and keel lifting control. Until now most hydraulic systems have worked at 250bar. Ward Proctor of the Finland-based company Marine and Hydraulic says 350bar not only provides greater hydraulic capacity when demand is high – in a full-on gybe, for instance – but also requires smaller diameter high pressure stainless steel piping, plus smaller pumps and motors. ‘This all adds up to important weight and space saving,’ says Proctor. But will the system provide the hydraulic flow required in heavy demand manoeuvres on the racecourse? Walker says: ‘Time will tell! One thing I do know is the boys always want more “juice”! We are confident we’ll have the “grunt” we need and we’ve made some substantial weight savings too. I predict that this will be the new norm,’ he added. The bridle can be used on one of three headsails set on separate furlers, each of which sheets to roughly 100 per cent of the foretriangle. The system employs what is known as
Left & above: three head- sails are set on separate furlers and sheeted to roughly 100 per cent of foretriangle. All three sets of sheets are precisely
controlled by a three-part bridle running through a
central ring to give precise, three-dimen- sional control of headsail sheeting angles from the helm, at the touch of a button. Itʼs a novel, lightweight solution that delivers optimum
performance while avoid- ing the need for tweakers and inhaulers
an absolute position indicator, which shows the trimmer the precise position of the pistons in the hydraulic cylinders at any given time. Baltic Yachts’ in-house project manager Tommy Johansson says through strict adherence to weight schedules and the dedication of the team on the shop floor, ways have been found to further reduce weight. Liara’s final light ship displacement was measured at 88 tons. Using CFD studies, MMYD was also able to confirm a considerable increase in performance provided by the yacht’s Retractable Propulsion System (RPS), especially in light to medium airs. ‘It was clear that the yacht would accelerate and power up much more quickly than expected with her propeller retracted,’ McKeon says.
A major engineering challenge for Baltic Yachts and the project team was posed by the juxtaposition of the hull aperture for the RPS and the telescopic keel. ‘It took us eight months to plan and engineer this, but we remained on schedule,’ Johansson says.
The yacht’s original machinery configuration was for a single engine and twin generators, but it was decided to fit a 60kW alternator off one of the main engine PTOs so that one of the conventional generators could be discarded, saving space and weight. The main engine is offset and drives the RPS via a 90°degree bevel gearbox. With a large lithium ion battery bank Liara can run in “silent” mode for up to eight hours with all “hotel” services running. MMYD worked carefully on the shape and positioning of hull
70 SEAHORSE
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