The Third Pair of Hands - By Don Gilchrist

A critical analysis of self steering concepts and their application in the cruising lifestyle.

Don Gilchrist is back practicing dentist (orthodontics) in Cairns, Queensland, Australia. He and his wife, Robyn have lived aboard their Oceanic 42 for ten years and have just completed a seven year circumnavigation. This article appeared in the June 2003 edition of Australia's 'Cruising Helmsman' yachting magazine. According to Don cruising is like Hotel California: "You can check out any time you like but you can never leave".

When I grafted an extra 1.5 meters on the back of "Stylopora" not only was I turning my back on Jack Savage's original idea of davits on the Oceanic 42 but I felt I was cutting wind vane self steering out of the script as well.

So far I have not felt the lack of davits but I was always ambivalent about foregoing wind vanes. In any collection of yachts a wind vane on the transom is as good a guide as any to the division of the serious cruisers from the rest. Initially I supposed there was a reason for this but I was carried along on a wave of high-tech euphoria. Wasn't the boffins latest brainchild GPS a triumph ? Hadn't our original electronic autopilot shown itself a proven performer? Didn't wind vanes steer yachts onto the rocks after a wind shift.?

So Stylo grew and wind vanes were reluctantly forgotten. Certainly backup was needed for our original wheel pilot and I chose a below decks model driving a hydraulic ram direct to the quadrant thus bypassing any future problems with the steering mechanics from the wheel back to the quadrant. Little could be worse than steering the boat across an ocean sitting in the aft cabin clutching the emergency tiller, hand bearing compass in your lap.

Our Coursemaster 450 has proven a strong performer but not without teething problems. "Electrical overload" and a "compass fault" were solved with a few electronic components in Ambon under faxed instructions from Richard Chapman at Coursemaster whose customer support has always been excellent and a hydraulic problem, which could have been solved in 30 seconds, had I perceived it correctly, saw us swap to the wheel-pilot for the top half of the Red Sea.

By this stage, particularly after the tragedy of the US yacht "Melinda Lee" being run down by a ship with loss of life off NZ, I had become aware that ships at sea are, to all intents, oblivious to the existence of cruising yachts. Forget all that nonsense of power and sail, port and starboard: they simply do not know you are there. If such an unhappy conjunction should occur the odds are that the yacht will simply disappear with all hands and no one will ever know why. If it were not for the miraculous survival of Judith Sleavin no one would have ever known about this one either.

The most effective defences against shipping on passage are a diligent watch and liberal use of radar. When the weather is bad no one wants to sit in the cockpit for their entire watch when the dodger is opaque with salt spray or rain and the cockpit cushions sodden. Amongst the heaving, foam-flecked seas any chance the watch on the ship has of seeing yacht navigation lights is minimal indeed. With the sea up and a few showers and squalls about a yacht just disappears into the background clutter for both eye and electronics on the bridge of the ship. But it is hard to hide 20,000 tons of ship from the yacht's radar within 15 miles in any degree of dirty weather. For radar to be useful it needs to be kept on, at least on standby, all night. At about 3 amps on standby and at least double that on transmit it's a fair drain. Add another 3 or 4 for GPS, nav lights, instruments etc. and a whopping 10 plus for a busy autopilot and you have a demand problem that few battery banks can cope with day after day. Such is the tyranny of the helm that crews scrimp to keep the autopilot working: radar, navlights, radio, ... everything takes a backseat to the autopilot and an autopilot that leaves its amps for the radar has lots of appeal.

Lying awake in the aft cabin as the Coursemaster grunted away, fretting about the rudder falling off, shipping and power consumption aboard yachts I decided to review the situation. I looked at many installations and quizzed their owners as I reached into my own mind to determine what I wanted a wind-vane to do for "Stylopora". 95% of self steering may be divided into two broad groups, each divided again into two subgroups:

ABOVE DECK: The plusses for this group are cost and convenience in that they are reasonably cheap and amenable to owner installation. There is minimal work below decks apart from getting power to the unit and putting the control head in some place where it is not too vulnerable to gratuitous trauma or the vagaries of weather. If they're cheap and you can put it in yourself then the spares/backup question is easy to answer: simply carry another one. Harder to answer are questions related to their limitations. Size and weight of vessel is not the problem. Inherent helm weight and system friction are. A 12 metre centre cockpit yacht with pull-pull cable steering and a large unbalanced skeg hung rudder will be beyond the capacity of the strongest wheel pilot in any developed sea. But a 12m aft cockpit cruiser/ racer with light steering and a balanced spade rudder will be quite manageable in most conditions. Broad reaching in fresh breezes with a lumpy quartering sea will be beyond this pilot type in any vessel. Speed and power of response will be lacking leading to an erratic course as the boat yaws around the ocean. At worst a crash gybe all standing could take the rig out of the boat and kill anybody in the way.

This type is totally dependent on the main steering system . If there is failure between the pedestal and the rudder shaft, hand control as well as autopilot have both gone for a Burton. For this category tiller steered boats have an advantage. But few production boats have tillers and effectively none over 11metres (36 ft) which excludes most yachts suitable for cruising and passage making. Centre cockpit designs are deservedly popular for cruising and they possess all the features that one should be cautious about. Wheel steering, unbalanced rudders and high friction mechanics severely limit the application of cockpit/electronic pilots for blue water cruising.

For day boats and weekend cruiser-racers they may however be ideal. The tyranny of the helm is not an equivalent threat for a friendly foursome between Pittwater and Sydney Heads as it is for a cruising couple mid-Atlantic.

BELOW DECKS: Such pilots can be powerful indeed. They may activate some part of the steering mechanics via a chain and sprocket or a hydraulic pump (this type is one of the few that can be adapted to hydraulic steering). The more direct route is onto the rudder shaft via the quadrant or its own dedicated tiller with some sort of linear drive.

These pilots can handle the heaviest loads on the biggest boats in any weather conditions ... IF you can keep the amps up to them!. Having high power outputs they have large power appetites. In heavy conditions up to 15 amps continuous is not unheard of. Because of their power they require sophisticated installation in an engineering sense. Flimsy supports and light weight fastenings will self destruct in no time. They are much more complicated for the novice owner to install and few are supplied with recommendations or instructions to that effect.

Instead of a control head and drive unit we are faced with drive unit, rudder sensor, fluxgate compass, junction box, at least one control head, often a hand held remote control and sometimes even a wind sensor. All of which has to be found an appropriate location and installed with its cabelling to enable periodic servicing. As well as being tidy and decorative enough to satisfy the mistress of the accommodations.

Most can be interfaced with the rest of the ships electronics through NMEA ports if you like that kind of thing. We do not. The meeting place for all nav info on Stylo is a paper chart interfaced by the human brain.

As well as their additional power they usually have some limited "intelligence " in that they are programmed to learn how to best control the boat as they go along . The increased economy of movement of our CM 450 is noticeable over the first 15 minutes. Above deck pilots sound busy. Below deck units can be decidedly noisy as they shove things to and fro. Ours is not nicknamed "Moose" for nothing. In our aft cabin Oceanic 45 his mechanicals are right under the bed and disturbance to the off watch can be significant.

Cost is a detractor as outlay approaches A$5000 or more. However if the vessel is used regularly for short handed cruises of a week or more the expense becomes justifiable. A combination of wheel pilot backing up a below deck unit would satisfy almost all of the requirements of full-time live-aboard coastal cruising.

SERVO-PENDULUM WIND VANES: This type are the most common wind vane with Aires, Fleming and Monitor being seen in any collection of blue water yachts. The idea was started by an adventurer, "Blondie" Hasler, who sought a system powerful enough to cope with the large, heavy , unbalanced, keel hung, tiller steered rudders of his time. He used a wind vane geared to angle a pendulum blade to the water flow which would drive the blade to one side or the other with great force. This could be coupled to drive the main steering gear to counter the change in apparent wind on the vane that started the process.

Servo pendulums are busy looking structures, amounting to a modest facsimile of an offshore oil platform on the stern. They work so powerfully that more than one user has told me "in fresh conditions when the pendulum feels the water flow human force cannot hold against it ". Consequently they have the power to shift the large, unbalanced rudders of big cruising yachts and overcome the friction of complex, centre-cockpit steering systems.

On the down side they tend to dominate the back of the boat to the exclusion of all else. They are vulnerable to damage and the connections from the pendulum drive unit to the main steering can be cumbersome and inconvenient. Light wind and sloppy sea conditions are the nemesis all wind vanes, servo pendulums uppermost among them. Low water speed equals low power output which comes up against a steering system undiminished in its friction or power requirements. When the rolling motion of the boat takes over as the main contributor to the apparent wind felt by the vane all wind vane control becomes ineffective.

Wind vanes tend to be ineffective motoring, unless some sort of electronic pilot takes over the input into the wind vane from the wind itself.

Servo pendulums are totally dependent on the main steering gear for their function. I do note however the German Wind Pilot sometimes combines a servo unit driving an auxiliary rudder. Servo pendulums tend to be vulnerable to damage as they swing out away from protection by hull, keel and rudder. To offset this they are provided with a fail-safe system in the form of a sacrificial sleeve or shear pin.

AUXILIARY RUDDER WIND VANES: Hydrovanes have been around for more than 20 years and have evolved steadily since their origin. Initially they came about to offset various intractable problems of servo pendulums: mainly dependence on the main steering, the complexity of connection to it and the servo machines poor performance in light air.

The theory of auxiliary rudders is that the vessels main rudder is locked to provide the basic balance, or "weather helm", on that point of sail. The auxiliary rudder then merely provides the trim corrections to keep the vessel on course. The auxiliary rudder can thus be much smaller than the main and fully balanced to minimise the power needed to move it. Thus allowing it to work in light conditions as well as heavy.

On the down side of auxiliary rudder types is cost. While they are visually less flamboyant than servo pendulums the engineering is reputedly more expensive.

They too tend to be vulnerable to damage and take over the back of the boat but not to the same extent as servos. Because the wind vane provides not only the control but also all of the force required to keep the vessel on course the wind vane itself is much bigger on Hydrovanes, complicating clearance of solar panels and mizzen booms as well as stowage.

Spinnaker work in light and sloppy conditions is not for wind vanes of any type. At such times things are better handled by "Moose". When things go a bit flappy there are fewer variables.

Their big plus is that they are independent of the main steering and indeed provide an effective emergency rudder in case of catastrophic failure of the main gear. There is on record in ARC rally archives an account of a boat of popular production design that lost it's spade rudder entirely mid-Atlantic yet finished the rally without fuss solely as a result of it's Hydrovane self steering gear.

Any kind of self-steering has the power to communicate back to the helmsman. If your electric model has 90 deg. of weather helm and is grunting away as while the vessel slews about the ocean. Or your wind vane is fully over to one side all the time with a noisy gurgle coming from astern the rig is out of balance and it is up to you to put it right. ALL auto pilots reward the balanced boat handsomely with longer trouble free service, better course keeping and more peace of mind. Nothing on a boat is set-and-forget and that is as it should be. Sail plan, course keeping, speed and comfort are all interrelated and the meeting point is boat balance DO NOT IGNORE IT.

Whatever the pilot, it is nice to be able to control it from a position close to the helm. Within the limits of weather resistance the control heads of all electronic types are flexible in this regard: although all the manuals say "Keep out of rain, spray etc." How you are supposed to do this and have it within reach of a yacht's helm at the same time is beyond me. Most windvanes have some kind of remote control, our Hydrovane Derek certainly does and it was no problem to route it to the centre cockpit for night use on passage and it was easy to stow when not in use. There are some adjustments that need to be done aft, at the unit itself but once "Derek" was set up for the general conditions in terms of windvane axis angulation he seemed to look after himself. We never had the need to go aft and do any of it at night on passage or in adverse conditions. All servo pendulums come with a wheel or tiller quick disconnect. Hydrovanes do not because the auxiliary rudder is so much smaller than the main and independent of it. In a crisis the main rudder overrides the auxiliary and you can sort it out later after the panic is over.

In the end our auto-pilot set up was: Plastimo wheel pilot, Coursemaster 450 electronic/electric/hydraulic and in Malta I fitted a Hydrovane for the long trans-oceanic passages and I have never regretted any of them. The back-up that each provides the other is unique and valuable in its own right. For a quick third pair of hands in tight pilotage or coast hopping on a light day the wheel pilot is great. When there is a long motoring job and the pilotage requirements are precise, with the kite up or the wind variable the CM 450 comes into it's own. The power and precision in any circumstance of weather is irreplaceable. But for a long haul of trade wind sailing in shipping lanes when you want to use radar a lot. Of knowing that no electrical failure can rob you of your auto pilot and sentence you to the tyranny of the helm for the duration. When you want quiet and peace for sleeping off-watch and the tranquillity that comes from knowing that you are carrying an entire spare steering system with you, the Hydrovane is peerless.

Having one each of 3 categories on board Stylo, have I overdone things? Perhaps and only perhaps and I think not anyway. After the structural integrity of the hull and rig and the reliability of the motor there is NO system on a cruising yacht more important than that which allows it to maintain its course without full-time hands-on human control.

All systems overlap yet none is complete. Only in the application of all of them, in their place, does the cruising yacht allow its crew to approach those peaks of freedom, comfort and peace of mind that are part of going cruising in the first place. There is plenty to do aboard a cruising yacht without having to hand steer her every inch of the way.

copyright - Don Gilchrist 1997 all rights reserved.