Assisted Sail Trim. Yes, there is a Robot capable of adjusting your sails. We tested it


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Screenshot 2016-04-01 at 11:14:47 a.m.The rendezvous is at the Old Port of Cannes where I board Jeanneau’s new Sun Odyssey 519 to try out the first boat available with Assisted Sail Trim on board, the revolutionary system invented by Harken and Jeanneau and capable of self-adjusting sails. Yes, you guessed it right, it’s a sort of autopilot for the sails, capable of adjusting them automatically by acting on three electric winches (two primary winches for the jib sheets and one in the deckhouse for the mainsheet, mainsail halyard, and jib furler).
Screenshot 2016-04-01 at 12:35:13 p.m.
We leave the harbor where more than 30 knots (gusts up to 37) are waiting for us: not ideal conditions to test this system, which, for safety reasons was set by the Jeanneau shipyard to work in a wind range of 5 to 25 knots. “For today, we made an exception,” Pietro Binda, the Harken project manager who invented this system, explains to me, “moving the limit to 35 knots, but these settings are usually set by the shipyard and not changeable by the owner.”2016-03-11-11-55-13-fbgrab
Assisted Sail Trim is, as a first step, software capable of making the winches work by themselves on adjusting the sails according to the wind direction and the boat’s course. Amazing, like an autopilot applied to mainsail and jib (the adjustment of the two sails is absolutely independent).
A console located on the rudder wheel column controls through a very intuitive display three electric winches and makes them work on their own automatically, after giving an initial sail adjustment. This is made possible by sensors on the winches that “know how to count” how many inches of sheet to let or caulk depending on how the apparent wind direction or the boat’s heading varies. In fact, these sensors can detect the rotations of the winch bell and thus calculate the distance traveled by the sheets.
But that’s not all, as the screenshot below shows, theAST is also capable of accompanying a manual tack (by cocking one winch and letting go of the other) but also of tacking itself. Also from the console you have control of all three electric winches intuitively as shown in the picture: on the dispaly the buttons are arranged as the winches are arranged in the boat.

Before activatingAuto Trim, the sails need to be adjusted according to the gait you have decided to keep. Once the sails are fine-tuned, you can operate the Auto Trim, which from that moment on will act like a real clubman, intervening on the sails depending on changes in the boat’s heading or wind direction. This means that a base of sailing knowledge is required anyway, because if the first manual adjustment is wrong, the whole automatic system will react accordingly to that first wrong adjustment.
We test it on the water, although the conditions are not optimal due to too much wind: once the sails are adjusted, I operate the autotrim and then barley. As if by magic, the mainsail and genoa sheets cock themselves following my rudder maneuver. I try leaning: here the “let go” maneuver is slower, because by leaning and increasing boat speed, the apparent wind direction remains the same for a short time and the system reacts somewhat slowly to the actual change in heading.


It is also possible to Also set the boat’s heel as a parameter (between 10 and 30 degrees): for example, if we set 24° as in the figure above, the system will let go of the mainsail when the heeling angle exceeds the set angle, then adjust the sails so that the boat does not exceed 24° of heeling. It will then behave like a straider in the midst of gusts (almost..) The ability to set this parameter is very useful when sailing with children on board or when, for example, you are cooking.


As a first step, once theautotack (automatic tacking) control is operated, the system checks whether you are sailing at the right angle to be able to make a turn: if not, it prompts you to tack to put you on the right course. Then it checks that what will be the new leeward sheet is recovered at the gisuto point (remember that the system has an exact number of meters of sheet to cazza to make the tack. For example on our boat the system knows that it has to take in 4 m of sheet and cazza on tack to come out of the tack at an apparent angle of 30/40°, if you come out too leaning the sails will obviously be too capped). If all is well, the system initiates the turn. You have to get the hang of it a bit, and I had to try two or three turns before I could get the timing of the turn (the system slack and cock at the same speed) and adjust my rudder movement.


If necessary, the AutoTrim system is deactivated simply by pressing any of the console buttons or by acting directly on the buttons on the deck of the electric winches. Importantly, it is a system that “assists” the sailor, but does not replace him or her; on the contrary, the crew must always be involved. The system then has four load limits with respect to the detected wind and which are considered as an immediate block to automatic maneuvering (even in the case, for example, that a knot forms on the jib sheet during a tack)

The AST is currently available as an exclusive option on the new Sun Odyssey 519 and is a Jeanneau exclusive for one year. But this system will be installable on any vessel having as its only condition the presence on board of the NMA2000 network with which it interfaces to detect the data it needs to work: wind intensity and direction. The cost is around 15,000 euros including the three electric winches, which taken individually would cost about 3,000 euros each. As for power consumption, it is the same as that required by classic electric winches to which 3 amps are added for the electtronic system. After 5 / 6 hours of sailing with the AST, the batteries were still at 95%. Obviously, the greater the wind intensity, the greater the loads and consequently the energy consumption. The Jeanneau shipyard is working on equipping the boat with such batteries to allow power autonomy for an entire weekend using the AST system.


This news item is part of the 12 most-read of 2016. Click here to find out all the other most popular news stories of the year!



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