The history of selfsteering

Shorthanded long-distance sailing started with just a few hardy pioneers - Joshua Slocum was one of the very first with his legendary Spray. It is said he could keep the boat on a fairly steady course using an ingenious sheeting arrangement or simply by lashing fast the wheel. This manner of self-steering willingly sacrificed a certain amount of sail power to free up a portion of the sail area just for steering trim. Of course, Spray had a natural tendency to sail straight, as her keel was...

Combining autopilot and windvane steering systems

Today autopilots are often standard equipment on a boat. They are a good option for everyday use in weekend and holiday sailing, but the case in favour of a windvane steering system grows with the length of the planned voyage, especially when sailing with a small crew, and is virtually irresistible for ocean crossings. There can be no doubt, in the end, that the best self-steering solution for blue water sailing is to carry both an autopilot and a windvane gear. There is one remarkably...

The rudder

The auxiliary rudder or pendulum rudder of a windvane gear effects the course correction either a. directly (auxiliary rudder system), or b. indirectly (servo-pendulum and double-rudder systems), the deflection of the windvane in the latter case causing the pendulum rudder to swing out sideways and, in turn, pass this motion via lines to the main rudder, where it carries out the corrective movement. An auxiliary rudder is an additional steering rudder which makes steering movements...

DIY construction

Twenty years ago the subject of home-made windvane steering systems merited a whole chapter in books like this one. But also, 20 years ago, of course, the average boat in need of windvane steering was small enough to make DIY projects a practical alternative. The average length of today's blue water yachts is approaching 12 m 40 ft, and even much larger yachts are not uncommon. Most owners have considerably better financial resources now as well, and with the general standard of fitting out...

System suitability

This type of system is particularly suitable in cases where 1. the boat is too large or heavy to be managed by a simple auxiliary rudder 2. the transmission paths are too long for efficient use of a servo-pendulum gear (especially on boats with a centre cockpit) 3. the planned voyage is long, the crew small and consequently the very best steering performance is sought 4. the presence of an emergency rudder is considered to be important, for instance on boats where the main rudder is not...

Windvane steering systems

Aries (spare parts for all existing parts) Aries Spares Helen Franklin 48 St Thomas Street Penyren, Cornwall TR10 8JW UK Tel ++44 1326 377467 Fax ++44 1326 378117 Aries Standard Peter Matthiesen Mollegade 54, Holm DK 6430 Nordborg, Denmark Tel ++45 74 45 0760 Fax ++45 74 45 2960 Auto Helm Scanmar International 432 South 1st Street Richmond CA 94804-2107 USA Tel ++1 510 2152010 Fax ++1 510 2155005 E-mail selfsteer aol.com Website www.selfsteer.com Auto-Steer Clearway Design 3 Chough Close...

Fin and skeg

The Sparkman & Stephens design office turned out a great many yachts in the 1960s and 1970s that are now considered to be classics. All old Swan yachts had a long fin and the rudder mounted separately on a robust skeg. The frame pattern was similar to that of the long keel designs and V shaped frames were used here as well to ensure comfortable sailing, gentle motion and peace down below. These boats were likewise tremendously seaworthy, but faster on account of their smaller wetted surface...

Materials

The materials used to manufacture windvane steering systems are normally determined by their production method. Most hand-made systems are fabricated from stainless steel. Aesthetic impression tends to be subordinate here to functionality, and such systems bear much of the blame for the reluctance of many sailors to (dis)grace their beautiful transom with a windvane steering system. Another consideration is accuracy of construction. Hand-made systems are almost always built within certain...

Autopilots for different purposes Holiday and weekend sailing

Most sailors use their boats primarily at the weekend or for holidays, which partially explains the rapid spread of electric autopilots. Power consumption is not really an issue on one-day trips and the quality of steering performance is also relatively unimportant since it is always possible to steer by hand if necessary. Sea conditions rarely impair steering quality as the majority of weekend sailors do not venture into exposed waters. Taking the helm in any case forms part of the fun for the...

Vessel size

Windpilot Pacific Light on a Crabber 24 Boats of 18m 60 ft at present represent the upper limit of what can reliably be steered by a windvane steering system. Bigger boats rely almost exclusively on electronic systems the heavy equipment and availability of auxiliary generators justifies the use of the most powerful autopilots. The corresponding lower limit seems to fall close to 5m 18 ft, a length of boat not unheard of for extended voyages. A gear appropriate in other respects for a boat any...

The first windvane steering system

The first windvane steering system, rather ironically, was installed on a motorboat. Frenchman Marin Marie used an oversized windvane connected to the rudder by lines to steer the 14 m 46 ft motor yacht Arielle during his spectacular 18-day single-handed crossing from New York to Le Havre in 1936. His windvane steering system is now on display at the Mus e de la Marine in Port Louis. British sailor Ian Major took Buttercup single-handed from Europe to the Antilles in 1955 using a small windvane...

Power consumption

The power consumption of an autopilot is determined not only by the rating of the model chosen but also by the following factors Length and displacement of the vessel. The more boat there is to move, the greater the power consumption. Type of rudder A keel-mounted rudder requires more force because it is impossible to balance. A rudder on a skeg can have a balance portion below the skeg and is therefore easier to steer. A fully balanced spade rudder without a skeg is lightest on the helm. Speed...

Drive unit

Linear Drive Arm Autohelm

There are four alternatives. 1 Mechanical linear drive unit An electric motor operates the push rod mechanically via a transmission. These drives are similar in principle to cockpit autopilots, but are considerably more powerful. The electric motor can be constant speed ( simple and cheap but power-hungry ) or variable speed ( more efficient). The mechanical linear drive is more energy efficient than its hydraulic linear sister but is also more susceptible to mechanical overload under extreme...

Mounting a windvane gear

Mounting a windvane gear on wooden, aluminium or steel boats poses no problems at all since all three materials have sufficient local strength. There is no real need to reinforce the inside of the transom and those owners who choose to anyway do so mainly for the good of their nerves. The inside of a composite hull transom, on the other hand, normally has no structural stiffening members and, depending on the particular boat and the system to be installed (weight, load distribution of mounting...

Damping

One of the first lessons of helming a boat is to steer as little as possible. Vigorous use of the tiller or wheel to correct the course tends to be ineffective because the boat always turns too far, immediately necessitating another course correction in the opposite direction and leaving a snake wake trailing astern. An experienced helmsperson, with greater awareness of the behaviour of the boat, keeps steering movements to a minimum, following one of two mental 'steering programs' 1. He or she...

Trimarans

The single rudder blade on a trimaran is much more easily controlled than the pair on a catamaran. Servo-pendulum systems can be used as long as the boat has tiller or mechanical wheel steering. Auxiliary rudder gears are less suitable because the outboard rudder of most trimarans makes proper positioning of the auxiliary rudder blade difficult. This type of gear also lacks the power required to cope with trimaran speeds. Double rudder systems are totally unsuitable. The two rudders of the gear...

H vane

There are four alternative approaches 1 Manual The locking device is released, the vane support is positioned by hand and the locking device is then tightened again (Sailomat). This method involves a crew member working right at the stern, which may be unpleasant or even dangerous at night. There is no scale to indicate the position of the vane relative to the wind. 2 Toothed wheel and chain The vane is positioned using a toothed wheel and chain arrangement similar to that on a bicycle. This...

Centreboard or internal ballast

Boats of this design, in which the ballast is higher up, derive their basic stability from their width. They are consequently wider than other designs and more sensitive to trim. Increasing heel is almost always accompanied by increasing weather helm, which creates more work for either self-steering option. The hull is generally of trapezoidal cross-section at the bow, which suggests a less comfortable ride at sea. A number of boats on the French market feature a small trimming rudder in...

Introduction

Throughout human history people have been taking to the water in sailing boats, be it for trade, exploration or war. Not until the twentieth century, though, did the idea first surface that a sailing boat might be able to steer itself. In the heyday of the tall ships, and even well into the modern era steering meant hands on the wheel. Crew were plentiful and cheap, and all the work on deck, in the rigging or with the anchor was performed manually. Where brute force was insufficient there were...

Deep fin keel and balanced rudder

This configuration offers greater speeds and improved manoeuvrability in harbour and is widespread today. The hull frames are trapezoidal in the bow section and wide and flat towards the stern, a design which is good for length along the waterline (and hence speed) and that promotes surfing, but that reduces comfort on board. These boats do not carve through the waves but rather bang hard against the water. They are noisy and uncomfortable to sail, but since the difference in comfort only...

A to Z of manufacturers

Founded in 1974 by British engineer Derek Fawcett, Autohelm has expanded continuously and has been worldwide market leader from day one. The characteristic 6 button operating pad was introduced in 1984 and remains unchanged AUTO - autopilot on +1 +10 - add 1 degree 10 degrees to the heading -1 -10 - subtract 1 degree 10 degrees from the heading and STANDBY. Autohelm merged in 1990 with Raytheon Inc., an American multinational with 70,000 employees and interests in everything from refrigerators...

Servopendulum systems

Since this is the most popular system today we shall devote the next few pages to a detailed look at its various features. The windvane rotates the rudder blade via a linkage. The rudder blade is mounted on a shaft which is able to swing from side to side like a pendulum (hence the name). When the rudder blade is rotated, the force of the water flowing past pushes against it and swings it out to one side. The shaft on which the pendulum rudder swings is connected to the tiller (or wheel) via...

The big misconception

Servo-pendulum systems operate on the basis of servo-dynamic force. Essentially, the mounting at the stern only has to withstand the force transmitted through the steering lines to the main rudder and support the gear itself. High loads, such as pounding waves, do not as a rule reach the gear, and breaking waves are more likely to knock the whole boat to leeward than force the pendulum rudder out of its position in the wake. A swell which catches the boat side-on acts on not only the pendulum...

Building a new boat

Diy Sailboat Windvane

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...

Trimtabonauxiliaryrudder systems How they work

The steering impulse from the windvane is passed to a trim tab attached to the trailing edge of the auxiliary rudder. As the trim tab is pivoted out to one side it pushes the trailing edge of the auxiliary rudder to the opposite side. The movement of the auxiliary rudder effects the course correction. The main rudder is fixed in place and used for fine trim in the same way as with a simple auxiliary rudder gear. Trim tabs are very small, normally no more than 20 of the area of the auxiliary...

The Windvane

The steering impulse in a windvane gear comes from the windvane. The vane takes its energy from the apparent wind flowing across its surface at the angle set. There are two types of vane, the horizontal vane and the vertical vane. The Vertical or V vane rotates about a vertical axis (the same principle as a weather vane). It always points directly into the wind, so the effective windvane area (the area actually subject to the action of the wind) is never very big. When the boat strays off...

The pendulum rudder material buoyancy shape and balance

A pendulum rudder should react as sensitively as possible to every steering signal from the windvane. A balanced shaft design and buoyancy in the rudder blade improve the sensitivity of the gear, and the shaft and rudder blade should ideally be no heavier than absolutely necessary. The loads on a pendulum rudder and its shaft are for the most part only moderate even pounding through waves is unlikely to damage the gear in its protected position at the stern. Nevertheless, the force generated by...

Multihulls Catamarans

Plans Catamarans

Catamarans have a relatively long length along the waterline and no ballast at all, and consequently hold a straight line very well. The pressure on the rudder is relatively low as well, so they are easily steered. They accelerate far faster than monohulls in the puffs, however, which causes dramatic fluctuations in the apparent wind angle. The same is true in the lulls they slow down quickly and the wind swings aft. The principle is as follows when a gust hits a monohull, it causes increased...

Swim ladders swim platforms and davits

Ideal combination of swim platform and windvane gear on a Roberts 53. The presence of a swim ladder in the centre of the transom admittedly makes installing a windvane gear slightly less straightforward, but the swim ladder is not necessarily as important on long-distance voyages as some people think. The idea that a swim ladder is an essential means of recovering a crew member lost overboard sounds good in theory, but MOBs are most likely to occur when the sea is rough, the boat is bouncing...

Long keel boats

This classic form dominated yacht building for many years. The long keel promised good course-holding abilities and great seaworthiness, and provided a sound structural backbone for any yacht. The rudder hung at the aft end of the keel. S frame construction combined with V shaped frames in the whole bow section ensured smooth passage through the water and a calm and comfortable boat. The courageous rescue missions of Norwegian sailor Colin Archer, who took his unmotorised double-ended cutter...

Overload protection

In the transmission components The steering lines of a servo-pendulum gear should always be pre-stressed rope and should have a diameter of at least 6 mm in or better yet 8 mm 1 3 in. Lines of this nature have breaking strains well above the maximum steering forces 300 kg 660 lb they are likely to encounter so they will stretch little in use. If the rudder suddenly loses control or the boat is hit by a gust, a servo-pendulum gear will exert its full force on the steering lines and the main...

Brookes Gatehouse

Brookes amp Gatehouse Ltd UK Premier Way, Abbey Park Romsey Tel 44 1794 51 84 48 Fax 44 1794 51 80 77 Website www.bandg.co.uk Brookes amp Gatehouse USA 7855 126th Avenue North Suite B Largo FL 33773 USA Tel 44 1202 63 21 16 Fax 44 1202 63 19 80 Cetrek Tel 44 1202 63 21 16 Tel 44 1202 63 19 80 Tel 1 610 495 0671 Tel 1 610 495 0675

Auxiliary rudder systems

An auxiliary rudder system is a discrete steering unit which steers the boat independently of the main rudder. The windvane turns a rudder blade on a rigid shaft directly via a linkage, maintaining the corrective rudder movement until the boat returns to the desired course. The main rudder is fixed in place and used to fine tune the gear. It counters weather helm, allowing the auxiliary rudder to concentrate just on actual course corrections. Auxiliary rudder systems are only effective if the...

Aries Standard ATLAS

Cape Horn Wind Vane

This windvane gear was built for many years in France and came in three versions trim tab on main rudder System type 8 trim tab on auxiliary rudder System type 6 servo-pendulum System type 11 None of the systems had bevel gear yaw damping and all consequently required very precise trimming of the boat. Production ceased at the end of the 1980s following the untimely death of the manufacturer. The Atoms servo-pendulum gear System type 11 was produced in Nice, France, for many years and was very...

Range of adjustment of an autopilot Autohelm

The rudder gain, which has nine settings, specifies how much the rudder should be moved to return the boat to a desired course. Oversteering will result if the angle is set too high understeering if it is set too low. 2. The Rudder Damping function has nine positions and serves to damp yawing motions. 3. The rudder amidships position in the rudder reference transducer has an adjustment range of -7 to 7 degrees. 4. The Rudder Limit function prevents the autopilot reaching maximum lock at full...

Rig sloop cutter yawl or ketch

Traditional long keel yachts were often yawl- or ketch-rigged to improve the balance of the sail plan. Especially in heavy weather the foresail alone struggled to keep the boat tracking on course increasing speed and heel pushed the centre of lateral resistance forward dramatically, generating substantial weather helm that had to be balanced out with a mizzen. Yawl-rigged boats are always easy on the eye this beautiful, tradinional yacht was moored in Newport, Rhode Island in 1996 Blue water...

Salomatsystem types and

Windpilot Caribic

There has been some confusion in sailing circles regarding the Sailomat name owing to the fact there were two separate companies using the name. The legal battle between the parties involved lasted for several years and unsettled the market. Sailomat Sweden AB was founded in 1976 by the three Swedes Bostrom, Zettergren and Knoos. With financial help from the Swedish treasury the company developed the Sailomat 3040 double rudder system. Elegant and innovative, the design was the first to couple...

Summary of the types of system

Power leverage PL see illustrations This provides an indication of the steering force obtainable from a system. The longer the lever is, the greater the steering force and, therefore, the better the steering performance will be. Servo power is generated by harnessing the force of the water flowing past the hull boat speed Vessel size see manufacturer's specifications The actual capabilities of a system with respect to maximum vessel size are subject to certain limitations point 1 . Remember...

Setting the wheel adaptor

Most wheel adaptors conform to the same basic design. The various models do, however, differ substantially in their technical features, as we shall now explain 1. The fixed drum - no adjustment possible Sailomat Cap Horn . Both steering lines have to be disconnected from the adaptor and shortened lengthened in order to fine-trim the course. This is not a straightforward procedure and fine trim is often ignored, resulting in less efficient sailing. Providing sufficient scope for such adjustments...