Work on the Real Engines

Even before the day I finally stepped into the void by taking the decision to equip Aluna with an experimental Polynesian style rig, I knew I had put myself on a path of seemingly endless tweaking, of having to do things at least twice but probably more, of solitary learning by making many mistakes, hoping to do each one only once, of having to come up with solutions from scratch all on my own, stretching my spatial and functional imagination to the point of despair, of managing things that cannot be properly understood while facing the fact that my life will depend on just those things, and what else can be said of the many dire consequences of going your own way, stubbornly carving your own path in the jungle of choices instead of hitching a ride down the nine line highway that connects the mass market to consumer land?

It was the morning of July 17, early dawn and we were about to face a moment of truth. Aluna had steadily wandered off course, unable to hold our strenuously gained easting. Staying on the 140th meridian to make landfall on the East coast of Nuku Hiva had become a goal slipping out of reach.  The feeble Southern trades were not strong enough to make headway into the current that dragged us westwards at probably some two knots. While Aluna’s bows pointed way upwind of our destination, the GPS revealed our actual movement over the seafloor almost 45˚ of to the side away from wind and waves. By now we were maybe 25 miles below the westernmost outpost of the Marquesas, the little uninhabited islet of Eiao, and daylight should soon allow us to actually see this little speck of land off our port beam. Would the slim landmass block the current sufficiently to tack upwind towards it and from there continue another 40 miles upwind towards our destination? The first gloom of light let our weary eyes wander in vain. The land must be there, but we couldn’t see it. It was not until the shy pink hues gained strength and burned into fiery orange flames that a dark blue hump on the Eastern horizon confirmed that we were physically where we had been led to believe by the paraphernalia of intellectual gadgetry we call upon for our navigating the modern world. We now needed to tack! All crew was on deck, ready to go through the by now familiar routine, which starts with me disconnecting the autopilot, before bearing off a bit to gain some speed, then turning the wheel over hard and bring Aluna into the wind and hopefully through it too. My right hand was just about to depress the lever on the autopilot’s clutch when my visual attention got caught up on the main sail’s forward edge about half way up the mast. Something was not right and my hand hesitated way before my brain became aware. Darn! There was a gaping hole between the spar and the sail and I knew too well what that meant. The spiral wrap that holds the sail to the spars had chafed through yet again and if we didn’t take immediate action the wrapping was to undo itself pretty quickly and we were to find ourselves with a loose piece of tarp flapping in the wind.

The way the crab claw sails are rigged traditionally the foot of the sail protrudes forward of the mast because it is tied to the bottom of it by a short piece of rope. So the vertical spar climbs up along the side of the mast and somewhere between the foot and the point where it is suspended about two thirds up, the two touch. On a boat, especially once out on the waves of the open ocean, everything constantly moves, so that touching becomes a rubbing and between the two wooden posts the brailing line literally becomes squeezed, squashed and finally mashed. To keep it in simple terms it eventually wears through and parts. This had happened a couple times already during the trip, so the remedy was known and clear: Take the sail down, patch the spiral wrap with a short piece of rope and put the sail back up before losing too much ground to the winds, the whole operation hopefully lasting no more then three quarters of an hour, especially now at such a critical time.

As you know the tacking eventually worked and we made it safely to Nuku Hiva, but a serious engineering review of the issue has since been brewing in my brain. It seemed clear to me that the sail needs to be held behind the mast, thereby limiting the contact between spar and mast to two points: the rope to block connection at the top of the mast and then a dedicated friction surface at the foot of the sail. The sail needs to be able to swing from side to side at least 60˚. There is a serious amount of pressure wanting to push the foot forward once the sail is up and working. So that needs to be taken into account. The foot needs to be securely held in place even with the sail violently shacking in a gust of wind. My anti-academically trained brain works slowly through these kinds of issues, trying to imagine the mechanism in all its different positions and situations, designing and discarding forms to fulfill the needed functions until something definite enough for the building of a prototype oozes out of the many folds of grey matter pressed inside my skull. Since I also had to finish work on the heavy weather mizzen, who’s bamboo poles had never received their proper treatment after it was hastily put together before departing in Honomalino Bay, it was going to be my prototype. This was even more convenient for that fact that its small size made it way more manageable than the bigger sails, which can be a pain in the you know what, just to spread them open for inspection on Aluna’s limited deck.

It took another week for the form to materialize out of a block of teak, and another one to sand and glass the bamboo sticks, but now things are taking shape enough to show you some pictures of it. I will get the camera ready first thing in the morning and still your eternal thirst for visuals. For now you may do your own exercise, rolling this problem around in your head to see what kinds of curious shapes you come up with. Maybe you’ll find yourself way ahead of the curve with something so incredibly beautiful, but at the same time totally functional and seamlessly fulfilling its purpose without being overbuild. Of course the rules of the competition limit the actual fabrication to a very limited set of tools: Cordless drill and circular saw are the only power tools available on board solar powered Aluna, the rest is hand tools, sand paper and simple pure old sweat! And remember: keep it simple, if it ain’t simple, I ain’t going to work. At least not for long…

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