Windlass wisdom

The best of offshore voyaging sailboats benefit from a set of intertwined design priorities that are linked to the job at hand. Structural integrity and operational reliability are two of the more important factors, and they apply to a wide range of attributes from hull scantlings to the fitting out process itself. The old adage “one size fits all” is best set aside, especially when it comes to adding gear such as the right anchor windlass aboard a long range cruiser. The growing trend toward installing look-alike hardware aboard both weekenders and long-distance voyaging boats defies the “job at hand” rule. Their anchor windlasses should be as different as a hatchet and an ax.

Choosing the right windlass is a bit like engineering the hull laminate itself, both should be based upon load calculations that simulate the conditions the vessel is likely to encounter. Increased exposure to wind and sea, both under way and at anchor, justifies both a stronger hull and an anchor windlass upgrade. Ground tackle and anchor windlass can become a voyager’s first line of defense when conditions deteriorate and a marginal anchorage turns untenable.

Unfortunately, lighter anchors, less chain and smaller windlasses have become something of a trend. For day sailors and weekend cruisers it may be an appropriate fad, but for those bound for remote landfalls, the anchor windlass takes on a whole new level of importance. And for those in the market for an upgrade, a mindset based upon operational reliability and power to spare needs to replace bargain hunting.

The voyager’s anchor windlass is like a mainsail that must also do double duty as a storm trysail. It needs to be designed to handle the worst of conditions and also take day-to-day use in stride. Attributes such as a larger diameter chain gypsy, a clutch release rather than sole reliance on the power down option, and a reduction gear design that will stand up to the test of time rank as high priorities. The compromise of a thimbleless rope-to-chain splice rode and a small compact windlass is not the right option for those headed off on a lengthy voyage. Skimping on a windlass purchase is lot like saving money by re-rigging with smaller diameter wire. In the worst conditions, the true value of the right anchor and ground tackle handling gear can be equal to the value of the vessel itself.

Picking the right windlass

The tough question, is what makes some windlasses better than others, and the best way to answer it is by tallying up the tasks that must be handled, and the actual loads encountered. One popular boating catalog advises that a windlass should be used only to lift the weight of the chain and anchor, correctly pointing out that the vessel’s engine should be engaged to lessen the tension on the rode and provide thrust to break the anchor free. Consequently, the resulting loads will be the sum of the anchor weight and the amount of chain suspended. The effect of buoyancy even helps by reducing the weight of steel and iron when they are immersed in water. So on first glance, it sounds perfectly reasonable for a vessel with a 50 pound anchor and 250 pounds of chain to be equipped with a 500-pound capacity windlass. Unfortunately, the marine realm is all about dynamic influences that defy static calculations, and a real world look at anchor retrieval paints a different picture.

Let’s tweak the entering argument with a wind shift and a modest 2-foot chop, gusts to 30 knots are linked to an unanticipated line of thunderstorms, and tranquility has turned into a middle of the night tempest. The new loads associated with the wind gusts and pitching bow significantly skew the calculations mentioned above, placing increased tension on the ground tackle and windlass. Even with intentions of using the vessel’s propulsion system to “unload” the energy imposed by the rode, yawing, heaving and surging put immense new forces into play. Add to this the timing and need to quickly recover the ground tackle in order to head for a safer anchorage, and the reasoning why long-term voyagers opt for heavy duty anchor windlasses is clear. Tension spikes of two or three times the calculated weight of the ground tackle is a regular occurrence, and undersized hardware will have trouble with the surging loads.

The energy developed between the moving vessel and the fixed sea bed is transferred from the chain rode to the boat via a chain gypsy, and the smaller its diameter the fewer links that are engaged in the process. Smaller units are usually also equipped with a smaller shaft diameter and a housing base with less surface area, features that negatively influence load transfer. In short, deep sea fishing reels are much larger than those used on the poles of fishermen out to catch flounders. The trend toward miniaturizing anchor windlasses may make sense for the casual sailor, but it’s the wrong choice for the voyager. Ideal Windlass Co. owner Cliffe Raymond, refers to the current market trend as a price point driven development, not the evolution of better technology. He continues to hold that, “when it comes to handling serious ground tackle, size counts.”

Power to spare

The golden rule of windlass selection says that it’s important to pick a unit with power to spare. The reasoning stems from an engineering 101 theory — a unit operated well under its safe working load rating is likely to outlast a unit repeatedly stressed to its max load. One voyager I knew kept blowing his anchor windlass’s breaker and remedied the problem by installing a 50 percent higher rated breaker. He never blew the breaker again, but he soon melted the windings in the undersized anchor windlass motor, and wisely replaced the unit with a larger rendition of the same type of windlass.

The vertical versus horizontal capstan debate rages on, and both factions have valid claims to rally around. However, when all is said and done, the horizontal windlass noses ahead as long as there’s room on the foredeck for its sizable presence. The key reasons for its dominance is the natural chain stripping action linked to the lead angle, and the straight drop of the chain accumulating below in a deep forepeak chain locker. This arrangement also eliminates the vertical windlass’s omnipresent deck leak linked to the shaft penetrating the foredeck. Add to all of this the versatility of having two separately clutched line/chain handling capstans or gypsies, and the reason for horizontal windlass choice grows even clearer.

Vertical capstan windlasses do have some compelling appeal of their own, and the first is their less obtrusive nature, at least from an on-deck perspective. They rely on a finger-like chain stripper that coaxes chain off the gypsy instead of simply letting gravity do the job. The up side of this arrangement is seen in situations where there’s less room for a deep fall, such as in shallower foredeck chain lockers. These units vary in capacity and the best of the breed sport large dive gears that rotate in oil baths providing high power reduction ratios and lots of torque.

Electric (12 or 24-VDC) windlasses are the overwhelming choice among voyagers, but there are also manually- and hydraulically-operated units offering some endearing attributes. The former uses the person on the foredeck equipped with a lever or hand crank as the prime motive force. Several decades ago, we sailed our 41-foot sloop to New Zealand via the South Pacific, enduring a year with a rope/chain rode and no windlass. One of our first projects upon reaching New Zealand was to swap a high-end wind point wind speed system for an anchor windlass. Today I continue to value and rely upon the hand crank Nilsson windlass and windex at the masthead.

In truth, a manual anchor windlass best suits those with good shoulders and a vessel under 40 feet and 10 tons displacement. Beyond that, electric and hydraulic options steal the show. The latter is a rare bird on mid-sized yachts, but a favorite among commercial operators. Its upside is its low RPM, high torque, small-sized motor that runs reliably and demonstrates some of the key laws of fluid dynamics. The downside is the costly addition of a pump, bracket assembly and high pressure hosing, not to mention the assault on an already crowded engine space.

Some larger yachts use a hydraulic system to run a bow thruster and windlass as well as a small dinghy launching davit. Because each are used at different times, the capacity of the pump does not have to be massive and plumbing the vessel with a high pressure hose makes more sense.

Windlass installations

The electric windlass rules the foredeck aboard most mid-sized cruisers, and with its convenience comes a few complications. Ohm’s Law does not favor low voltage DC current transport, especially when it comes to carrying lots of amps over half the length of the boat. Batteries are usually located in the amidships portion of the vessel and the 100-plus amp appetite of a 12-VDC windlass is a long way away. This current demand is equivalent to that of the high load of the engine’s starter itself, and as Mr. Ohm so elegantly portrayed in his E = IR equation, resistance is the enemy of energy transfer. Low voltage can safely shuttle a lot of current, but it takes thick copper wire to get the job done. Leads in the diameter of a welder’s cable must be snaked forward and the longer the run, the heavier the gage of the wire. Windlass manufacturers provide tables specifying run length and wire size.

Some skippers prefer to install a secondary power source in the forepeak. This is usually accomplished by providing the windlass with its own 12-VDC (starting type) battery and simply bring smaller diameter charging leads forward to the battery. In either case, a breaker and solenoid operating deck switch need to be added, and all electrical connections need to be as protected from moisture as possible. Going to a 24-VDC windlass cuts the current demand in half, but adds more complexity to the ship’s system battery bank. Conversely, opting for a 120 or 240-VAC drive motor, run from a generator, puts too much high voltage danger into a very wet portion of the vessel.

Corrosion abatement

The foredeck is unfriendly to dissimilar metals and electrical connections, and the last place where aluminum cases and unbushed stainless steel mounting bolts will benignly coexist. Corrosion abatement is part of the design process and whether it’s a sealed solenoid box or a plastic dielectric sleeve in the mounting holes, attention to detail pays off in the long run. The same goes for the under-deck reinforcement used to anchor an aftermarket installation. Many older, ocean-capable sailboats sport only modestly reinforced foam or balsa core fore decks that were built without the designer contemplating the instillation of a powerful windlass. In such cases it’s important to add reinforcement under the deck that can be accomplished with fiber-reinforced polymer, aluminum, or plywood and epoxy.

Most windlasses work just fine on a bright sunny day when the sea is flat and the bow willingly faces into a light breeze as the rode and anchor clatter their way home. Combine a 0300 squall that can turn a safe anchorage into a seething caldron with a groggy crew summoned to the pitching foredeck, and it’s clear why veteran voyagers have great admiration for a powerful and reliable windlass. The bottom line resides in the art of prioritization, and knowing what gear is truly essential.

Ralph Naranjo is a freelance writer and photographer living in Annapolis, Md.

By Ocean Navigator