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When surveying the considerable number of new boats, both production models and one-offs, built for long distance sailing it is apparent that many errors are made with respect to self-steering equipment. When buying a brand name production yacht many sailors simply rely on the competence of the broker. The boat then arrives with a whole host of complex electrical and electronic systems and only later on does the owner discover how important (or unimportant) individual items are. Indeed there are even a few larger boat builders who simply refuse to install windvane systems or offer offset swim ladders as a build option on their blue water yachts because this disrupts production. There is also perhaps an assumption here that somebody in the process of buying a new boat will be too preoccupied with other things to get around to requesting relocation of the swim ladder, even though it would create very little extra work for the builders. Of the huge number of Hallberg Rassy yachts currently steered by Windpilot, fewer than 5 had the gear fitted during production!

Sailors do however seem to be increasingly aware when buying a new boat that the ideal solution to all self-steering problems is a well-matched autopilot and windvane steering gear, a subject we shall return to in the Chapter 7.

If you plan your self-steering requirements carefully it is worth considering fitting a relatively small autopilot for operating the main rudder in addition to a windvane gear. Each system will then be in a position to cover different wind and sea conditions and the total expense will be lower. Boat builders usually install powerful autopilots, but these may well be inappropriate alongside a windvane gear because the autopilot will be used predominantly in calms and for motoring.

inappropriate alongside a windvane gear because the autopilot will be used predominantly in calms and for motoring.

Diy Sailboat Windvane

Self-steering gear is standard on these yachts moored at Las Palmas, November 1995

An important design consideration when building a one-off for long distance sailing is the fact that once at sea steering will belong almost exclusively to the 'iron helm'. The operating characteristics of the planned self-steering equipment, for example a windvane gear, should therefore be reflected in the design: tiller steering is always best for a servo-pendulum system (see Transmission to tiller steering). Even large, heavy ships can be designed with tiller steering if required. Some sailors will still prefer wheel steering, either as a matter of personal taste or because they are planning a centre cockpit. The inherent inferiority of wheel steering with regard to force transmission from servo-pendulum gears can easily be overcome by routing the steering through the emergency tiller. Many French wheel-steering boats feature an arrangement in which the force from the wheel is passed directly to the emergency tiller via lines rather then passing through the deck to a quadrant: free the tiller of the lines running from the wheel and it is ready for connection to a servo-pendulum gear. This makes an expensive double rudder system unnecessary.

Not only does tiller steering outshine wheel steering in terms of reliability and simplicity, it also indicates errors in trim or balance (for example of the need to reef) much more clearly. The tiller strains visibly when weather helm is excessive.

Sometimes a hydraulic rudder system is essential for design reasons, for instance if the boat has more than one steering position. Servo-pendulum rudders are only compatible with hydraulic steering given certain preconditions (see Hydraulic wheel-steering systems, p 61), so it is usually necessary to go with an auxiliary rudder or double rudder system. A reliable means of blocking the hydraulic system and keeping the main rudder stationary is absolutely critical here; if the main rudder is subject to the influences of wave action the windvane gear will be functionally useless. It may eventually be necessary to physically fix the main rudder in place using the emergency tiller, which makes operation laborious because the emergency tiller has to be released every time the main rudder trim is altered.

The main rudder should ideally be well balanced. This keeps the required steering force low, enhancing the sensitivity of a windvane steering system and saving power with an autopilot.

The deck layout aft should reflect the fact that a wind vane works better upwind the less turbulence it encounters. Seats, liferafts, dodgers on the lifelines, high cabin tops close to the stern, etc. reduce the sensitivity of a wind vane. Spray hoods and other projecting structures further away from the stern cause no such problems since no boat sails much closer than about 35 degrees to the wind and from the wind vane this angle encloses nothing but open sea.

The bolts supporting a windvane steering system should always be accessible from the inside of the boat. Care must be taken not to obscure them when working down below at the stern, for example when fitting out an aft cabin. If you are fitting a system on a finished boat and the aft cabin has wooden panelling, the best advice is to drill the bolt holes right through the hull and panelling from the outside and then cut away the wood around the bolt holes from the inside using a circular cutter. Once the system has been mounted the holes can be covered with wood, leaving the bolts concealed but readily accessible.

The desired transom form is also of key importance when building a new boat. Modern transoms with an integrated swim platform (sugar scoop) are ideal for the installation of windvane steering systems as long as the platform does next extend too far aft, as this entails extra mounting work. Double rudder systems may even be installed with the auxiliary rudder part protected within the platform, either by inserting the shaft of the auxiliary rudder through the platform or, better still, by integrating a slot into the back of the platform. The pendulum rudder part in any case remains clear of the swim platform and can easily be swung up out of the water.

Another consideration for owners eyeing up the aft cabin as the owner's cabin: autopilot drive units operating on the rudder quadrant directly under the berth can be quite noisy and have been known to drive sailors out of their bunks. Mechanical linear drive units are much noisier than hydraulic linear drives.

Too many sailors wait until the very last minute before deciding to fit a windvane steering system. By this time, with departure imminent, the stern is already fully loaded and the ensuing tide of compromises required to find space for the vane gear causes sleepless nights for both owner and manufacturer. The fault does not always lie with the owner, however. Some boats have particular features which necessitate extra mounting work and additional (heavy) supporting structures. Worst of all are those with a platform at deck level whose design all but precludes the installation of a windvane gear. Often the only solution is a set of additional heavy mounting brackets below the platform, a proposition which tends to send owners into shock. The moral of the story is: lack of foresight with regard to the layout of the aft end of the boat is very difficult to rectify later on and the requisite compromises habe a tendency towards the aesthetically offensive.

Sugar scoop of a Carena 40 fitted with a Windpilot Pacific Plus ready for an Atlantic Crossing in November 1996

Diy Sailboat Windvane
Sugar scoop of a Taswell 48 showing a Windpilot Pacific Plus system with the pendulum arm in the raised position.

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