Know-How

Alternative Rigs

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Sailors are a conservative lot. The sea takes no prisoners, and most people don’t care to experiment when the cost of failure is potentially great. That’s why both futuristic and some older traditional sailing rigs struggle for acceptance and often receive little more than patronizing smiles from so-called modern mariners.

Ironically, the conventional marconi rig that now dominates sailing is supported by a complicated maze of heavily loaded stays and shrouds that in turn depend on a plethora of pins, toggles, turnbuckles, tangs, and what-not. If any of these parts happen to break, the whole rig comes tumbling down. Thus many more-adventuresome sailors (and some more-traditional ones) favor alternative rigs that are simpler in concept and generate lighter loads. These rigs are functional, they’re fun to sail, and they encourage us to think a few degrees west of the equator.

The German engineer Wilhelm Prolss developed this concept in the late 1950s in hope of reducing the cost of ocean transportation by putting motorsailing rigs on large commercial vessels. It wasn’t until American entrepreneur Tom Perkins enlisted naval architect Gerard Dijkstra and builder Perini Navi to convert a 289-foot steel hull into the famous Maltese Falcon that the idea became reality.

Maltese Falcon has three 191-foot freestanding rotating carbon-fiber masts that each fly five square sails (from top to bottom: royals, topgallants, upper tops, lower tops, courses). Each sail furls onto rollers inside the mast through vertical slots in the spar; each sail’s head and foot are set in internal tracks in the yards. A total of 75 electric furling winches are used to control the sails. Each of the 18 yards is cambered to allow for proper airflow; they provide such excellent support that there is little loading on the Dacron sails, even in heavy weather. Maltese Falcon is designed to carry full sails in 55 knots of true wind.

Amazingly, Falcon can be piloted by a single person who controls the helm and sail trim from a computer station. Unfurling the sails takes 6 minutes, and tacking takes 1.5 minutes; Perkins claims that gybing is a trivial task that, to a passenger, is virtually unnoticeable. Each mast is embedded with a mesh of optic sensors that change their light transmissions in response to strain and load, allowing the pilot to see, on the displays, how much stress is being experienced by the rig. To change the sails’ angle of attack, the helmsman simply rotates the 35-ton masts. Easy.

The AeroRig is a variant on the Balestron rig, which was used on model boats long before it appeared on big sailboats. It comprises an unstayed carbon mast with a single boom constructed across it at gooseneck level in a sort of asymmetric cruciform. The main portion of the boom extends aft as usual, but is partly balanced by a shorter foreboom section. The entire rig is supported by massive bearings situated between the partners and the mast heel and pivots freely through 360 degrees.

The sheet for the roller-reefing jib leads down to a short track mounted across the foreboom. This works like a miniature mainsheet traveler, and the slot between jib and main can be adjusted by trimming or easing its control lines. The sails are set at the optimum angle to the wind by a single mainsheet.

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