Advantages and Disadvantages of Wind Powered Autopilot
Denis Korablev
  • 12.10.2021
  • 340

Advantages and Disadvantages of Wind Powered Autopilot

Sailing is an exciting and extreme adventure that will be remembered for a lifetime. Yachtsmen, unlike tourists, know from their own experience how actual yacht management differs from commercials. Long voyages, the struggle with the elements, the tedious and monotonous work of keeping the ship on course - this is also yachting, everyday and hard work on the sea.

Hoping to make their daily work a little easier with the help of simple devices, yachtsmen tried to create mechanisms that could replace a crew member at least for the shortest time. But it was impossible to create a machine that could react to changes in the environment.

The most acceptable option for creating an autopilot, tested in practical use, was invented by George Braine at the beginning of the last century. He invented a system of blocks, rubber bands and ropes, with the help of which the sails were connected through a special drive with a stock on the rudder. The original design, in a heel or gust of wind, brought the yacht, dumped the wind from the sails, and returned the boat to its course. Brain's system could for some time free the helmsman from the monotonous work of keeping the course, but not for long. The design was not perfect and needed to be reset when changing tack. And this already required the help of the coastal team.

Whatever it was, D. Brain, who created the prototype of the autopilot before the First World War, is considered the inventor of the disembodied crew member. Brain's idea to combine a sail with a yacht rudder formed the basis for subsequent modernizations and improvements to autopilots using mechanics.

Frenchman Marin Marie, making a solo 18-day transatlantic voyage from New York to Le Havre, used a device representing a large area sail (wind wing), connected by ropes to a rudder blade ... An uncomplicated system could, at least for a short time, replace a brave yachtsman, and give him the opportunity to do other urgent matters. The transition ended in triumph, and the M. Marie system took an honorable place in the Maritime Museum of Port Louis. This design of the wind autopilot turned out to be very successful, and was later used in solo voyages by J. Major (Europe - Caribbean) and M. Henderson (1955)

The massive use of wind autopilots in the first OSTAR (Observer Singlehanded Race) races showed that without these assistants, the successful completion of the races would hardly have taken place (Plymouth, 06/11/1960) (area 4 sq.m.), connected to the tiller by a system of blocks and ropes. A 12 kg counterweight was used for balancing. But even at the same time, the design remained unstable, and it was urgently necessary to solve the problem of balancing the area of the rudder blade and the wind wing.

The method of keeping the course was used quite successfully, with the obligatory constant direction and strength of the wind. The drive from the mainsail or staysail to the tiller had a rubber shock absorber to compensate for the loads. This method of wind autopilot was both working and emergency for boats with a full keel and tiller, but was absolutely not suitable for boats with a steering wheel due to the low speed and low thrust from the sheets. Over time, this method of mechanical course keeping became a thing of the past, like boats with a tiller.

Wind turbines were divided into three types, differing in the type of drive to the rudder of the yacht:

  • Direct transmission. The system is an independent rudder, directly controlled from the wind stylus. Has no ropes or drives to the cockpit. The design has been tested in extreme conditions of the "around the world", and received the highest marks of professional yachtsmen.
  • With a flap (trim tab). There are various modifications of this system. With a flap on the main or additional rudder. The auxiliary feather of the wind turbine can successfully replace the main rudder in case of breakage.
  • Turn-transmission (servo pendulum). A construction in which the wind rider controls the feather of the wind turbine in the water. Under the pressure of the head of the incoming water, the feather of the wind turbine deflects to the right or left, while the cable drive to the steering wheel starts to move and corrects the rudder course. The auxiliary feather of the wind turbine is successfully used as an emergency rudder.

Although wind farmers are morally outdated, all long-distance yachtsmen advise to have them on board. One of the famous yachtsmen, Alva Simon, who has participated in many long voyages, highly appreciated his "Aries" wind turbine. This wind autopilot has accompanied the sailor on all voyages for over 30 years, without significant damage. At the same time, as noted by A. Simon, he had a huge box of spare parts removed from electronic autopilots, broken during the same period. In the event of a breakdown of a modern autopilot, the wind turbine will always help out, and will properly navigate the vessel while the crew is busy repairing the main autopilot.

Wind farmers are comfortable on large crossings, and found their admirers in the ocean expanses, where constant winds are observed. New (for those times) technologies found application in yachting. In 1970, Tillermaster produced the first electronic autopilot, pioneering the use of servos in yachting.

The modern autopilot system on a yacht is considered one of the most advanced and technically sophisticated equipment on sea vessels. The latest steering systems increase yacht speed while significantly saving fuel consumption. But the electronic rudders, which replaced the mechanical autopilot, have become the reason for incessant discussions on the topic: "Which autopilot is better?"

If the issue of installing the autopilot is finally resolved, when choosing such an assistant, it is necessary to proceed from the type of yacht and the conditions in which it sails most often yacht for rent, used in regattas, etc. With long-term transitions, you will have to use a mechanical drive unambiguously, with the possible use of an autopilot. Buying and installing an autopilot is a costly undertaking, but justified.

Wind autopilots are completely autonomous and do not need power sources. Their reliability and simplicity of design inspire confidence in all professional yachtsmen. There are two main types of wind autopilots - servo and auxiliary pen. These systems are associated with a wind wing having a counterweight, horizontal and vertical axis.

The installation of an autopilot on a yacht, regardless of the type of construction, involves the installation of a wind wing. Before starting to use the autopilot, you need to balance the yacht, level the waterline by moving the load closer to the midships, and according to the weather, reef the sails to the optimal size. The wind wing should not be installed in the shade of the tuning, and it should not be subject to turbulent flow due to the solar panel or rails. Thereafter, during the sea trials, the yacht should sail confidently and smoothly. You can experiment with wing angle and cable tension, preferably in different weather conditions.

The simplest autopilot consists of a separate additional rudder blade with flaps. The weather vane, which is part of the structure, is connected to the flaps with the help of cables. The principle of operation of such an autopilot is simple and ingenious in terms of efficiency. The feather of the weather vane is installed vertically, edge up. If the yacht changes course, the angle of the wind towards the weather vane also changes and makes it tilt. A cable attached to the weather vane sets the flap on the rudder in motion, as a result of which the rudder turns until the weather vane returns to its original position. Course restored! The weather vane is capable of keeping a course in difficult weather conditions, and the crew takes the helm only in the worst weather.

Autopilot drives are set depending on the size of the yacht and the type of its steering coordination system. To set and maintain a course, the ship's autopilot must receive the necessary input from an electronic compass sensor. The autopilot remote control is often combined with the multifunction display at the helm. This provides manual control over the operation of the automatic piloting system from any location. The servo design connects the wind wing to the servo blade. This is necessary due to the insufficient force created by the vertical pivot wind wing for confident control of the yacht's rudder. The rudder blade, like a pendulum, is shifted from side to side. At the same time, the water running onto the turned feather creates a hydraulic force that is greater than the wind force transmitted when turning by the wind wing. The yacht's steering wheel is rotated by means of a pendulum through a system of blocks.

The practical use of such a system has shown one drawback that does not allow the servo pendulum to work with a large steering angle. This is due to the low stroke of the pendulum and the cable - about 30 centimeters. A positive feature of using an autopilot with a servo is the ability to raise the feather from the water if it is not needed. In addition, the servo can steadily keep the yacht on course in the most adverse weather conditions. For example, if a wave strikes sharply and instantly leads to the wind, the wind wing is triggered, which through the servo turns the rudder blade, returning the yacht to the previous course (broching). The design of the autopilot with a servo drive is universal, and unlike the system with an auxiliary wing, it can be installed on many hulls (catamaran, trimaran). The system with an auxiliary feather is an additional feather attached to the stern. The auxiliary feather is driven by a wind wing with a horizontal or vertical axis of rotation.

When installing the system, the yacht's main rudder is fixed along the center plane (or slightly at an angle) to compensate, depending on the situation, drive or knuckle. The plus point of the extra nib system is the no cables going to the stock. Small wiring from the device to a convenient place in the cockpit for remote selection of the desired course, makes the process of controlling the autopilot convenient and comfortable.

The rudder nib is under constant hydrodynamic stress, which causes the rudder to fail, but when using an optional rudder, the main nib can be locked. In such situations, the presence of an additional feather on board is very appropriate and is an undoubted advantage of the design, because the feather can be used as an emergency rudder.

According to experts 2yachts, the disadvantage of an additional feather is that it cannot be lifted to remove debris and algae ... The disadvantages include the high cost of basic models with an auxiliary pen, which is 25-40% higher than models with a servo drive. This is due to the high cost of materials used in the manufacture of the auxiliary pen. Thanks to modern technology and the use of cheaper materials, the price difference will soon be eliminated. Among the abundance of offered models of autopilots for yachts, the most reliable and practical ones, having an excellent price-quality ratio, have gradually emerged.

Some of them can be highlighted:

Simrad Yachting AP35 system

It's worth noting right away that this autopilot has a very big plus - it works great in all weather conditions, since its body and interior are made of solid aluminum, and it is equipped with a modern LCD-screen with a special backlit, which allows it is good to see what is written on the screen at any time of the day. Each main function has its own button - this allows quick operation and on-line programming. The autopilot also supports the Robnet network, used for data transmission over a distance. It is also worth noting that this autopilot has the option to block the function from others, which will allow you to delay the function exactly until the moment you need it. The autopilot also has a rotary sensor that allows you to change the heading with an accuracy of 1 degree. The price of the Simrad Yachting AP35 system autopilot without a controlled device is about $ 2,000, and with a control device - $ 3,000.

Northstar Explorer AP380 Autopilot

This is one of the most popular automatic yacht steering systems. The autopilot has a 3.8-inch LCD screen with clear backlighting and images. The main menu allows quick access to all locations and options. The control system consists of two indicators, a joystick and a GPS navigator, which allows you to pinpoint your location. The price of this yacht steering system is about $ 600, and with a package that allows for more options, it is $ 1200-1800.

Steering autopilot for yachts Raymarine Smart Pilot X-5 Wheel

This model is very good and easy to operate - it provides the autopilot software, a comfortable steering wheel and a backlit screen, which allows good visibility not only at night, but also in bright rays of the sun. The advantage of this automatic control system for a yacht is not only that it is simple and convenient to operate, but also its cost - 1500-2000 dollars!

S1 Wheel Pilot - autopilot for sailing yachts with steering wheels

Well, let's discuss this popular autopilot model as well. Firstly, the latest software is considered a big plus of this automatic yacht steering system. It will allow you to locate your location, set your course to 1 degree accuracy, and is very easy to operate. Manufactured in Great Britain. It should be noted that the price is noticeably higher than that of other manufacturers (it is 3800-6000 dollars), but this particular model will become your indispensable assistant on the ship, since its modern software is literally ahead of time.

Naturally, the technological process does not stand still. More recently, one of the engineering firms in the United States (Virginia) presented a concept of a superyacht designed for autonomous sailing. The artificial intelligence, which the vessel will be equipped with, will not only control all onboard mechanisms (including autopilot), but also control systems that can work without human assistance. The autonomous technology of the new superyacht will focus on three main areas: navigation, equipment health monitoring and automation of mechanical and electrical systems.

This, of course, seems fantastic, but there are already ships in the commercial and navy operating autonomously. Perhaps in the near future, AI autopilots will make the yachtsman just a passive observer. Maybe ... but we will lose something forever - romance, extreme and pleasure from sea travel.