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TRADITIONAL CLASSIC YACHTS / MODERN YACHTS:
All traditional and classic yachts designed by us feature modern underwater bodies, e.g. short keels (if requested with ballast bombs) and spade rudders. Moreover we try to a design for a displacement level that is realistically achievable in modern boatbuilding. Hence with our designs, the usual 20% need not be added to arrive at the real displacement figure.
HULLS:
Fine entry angle for good penetration when beating, otherwise plenty of beam for stability and space inside. Wide powerful transoms are required for speed and easy steering when sailing offwind.
Very fast cruisers (which are comparable pricewise to shorter yachts with the same sail area) should be long and slim for effortless handling.
SAILPLANS:
Roached Mainsails: A new development are mainsails with large roach, combined with narrow foresails instead of having standard triangular mainsails combined with large overlapping genoas. With roached mainsails the missing sail area of the foresail (genoa) is transferred into the mainsail, which is highly efficient due to its elliptical shape.
With narrow foresails, the tiring winching-in of a large genoa falls away. A welcome side effect of a roached mainsail is reduced weatherhelm and less heel of the yacht, both of which translate into higher speeds.
With swept back spreaders, the runners are only used to improve upwind performance or for additional safety when running downwinds in heavy weather.
Examples of yachts with roached mainsails: BRISTOL 35, CLIPPER 39, CLIPPER 39E, CLIPPER 43C, CLIPPER 54, GITANA 54.
Freestanding Carbon Masts: With the price of carbon fibres dropping annually, freestanding carbon masts will soon come within the reach of cruising yacht owners. Freestanding masts have been built for very fast narrow 60 ft sleds.
The advantages are:
- increased safety: no bolts or fittings holding the shrouds that can brake (the most frequent failure source). With maximum bending being the critical path in the design process, the resulting safety factors in respect of breakage are higher than with conventional masts with their high compressive loads. In this connection, it is interesting to note, that a manufacturer of freestanding masts grants lifelong guarantee on their masts against breaking.
- specially suitable for roached mainsails
- no shrouds creating turbulence, hence higher efficiency of the sails.
- no damage of the mainsail by chafing against shrouds and spreaders
- shape of the mainsail is not distorted by leanig against spreaders and shrouds off the wind
- the mast curve can be optimized by adding external carbon reinforcements at selected areas.
- lower weight of the rig and lower centre of gravity, the yacht becomes stiffer
- with increasing windspeeds, the freestanding mast produces a controlled bending at the top thereby shedding windpower, hence less reefing is required.
Hoyt-Boom: Another practical development are jibs with HOYT-boom ( see CLIPPER 39C / CLIPPER 39E ). In this case the shape of the foresail remains unchanged and very efficient under all sailing conditions since the clew of the jib is held down by the boom, thereby giving the sail a reaching and downwind performance comparable to an Aero-rig. An additional bonus is the comfortable handling of this self-tacking jib, which only needs one small sheet winch.
FIXED KEELS:
For cruisers, we prefer moderate length keels with low draft, non-critical sections, that counteract leeway even with growth on the keel. For more race-orientated designs, deep, narrow sections are preferred.
LIFTING KEELS:
They are preferred over ballasted swing keels, since the internal structure (with the keel casing going up to the coachroof) is even stronger than with fixed keels, which in the case of Aluminium yachts are only welded up to the hight of the floors.
We design lifting keels with or without bulb.
With bulb: in this case the entire ballast can be concentrated into a torpedo or increased thickness at the bottom of the lifting keel, thereby producing the required stability with less ballast, making the boat faster due to its lighter overall displacement.
Without bulb: this reduces the minimum draft and enables the keel to be pulled out of the hull through the coachroof for painting even while the yacht is afloat. Moreover, when anchoring with the lifting keel and rudderblade fully hoisted, the yacht will lie in wind direction and not swing up to 60° both sides as is often the case with fixed keels boats or some swing keelers, where a large portion of the keel protrudes under the canoe body even with the swing keel fully hoisted. And, as a round-the-world sailing friend of mine observed, with fully retracted lifting keel and rudderblade you could beach your yacht when a tropical gale approaches.
UNBALLASTED SWING KEELS:
We use them for smaller designs up to 31 foot (in order not to spoil the inerior), in combination with a shallow ballast keel, also, for larger yachts with interior ballast which frequently come dry in tidal waters.
Unballasted swingkeels are more forgiving when hitting a submerged object, since due to their light weight they easily swing up as opposed to ballasted swingkeels, where considerable damage can be afflicted to the swing-mechanism, before the heavy keel comes up.
RUDDERS:
We prefer transom-hung rudders for yachts up to 45 ft, since they operate with the longest lever and can be easily repaired - even at sea. They save expensive rudder shafting and the rudder angle is immediately visible. An emergency tiller can be easily mounted.
The argument that transom-hung rudders ventilate more than spade rudders is only valid in uncritical situations, i.e. when the boat is not heeling (and the spade rudder´s root not exposed to the water surface).
STEERING:
Standing on an uneven surface behind the steering wheel, with the full blast of spray into the face is not the ideal steering position. Therefore, up to at least 45 ft. LoA, we prefer tiller steering (even Open 60´s are tiller-steered), combined with an expandable tiller extending up to 2.5 m, so that the skipper can sit protected under the sprayhood or extended decksaloon roof. In port, the tiller is tilted up and the cockpit left free for harbour parties.
O. Berckemeyer
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