How to Choose the Right Anchor Windlass

Deciding which windlass is best suited to your boat is sometimes easy and other times takes research. Imtra product expert Jim Thomas leads you through the process.

Whether your boat is 26 feet or 10 times that, finding the right anchor windlass to handle your anchor-hauling duties requires similar steps. There are many types and brands of windlasses on the market, and many of them can do a good job for you. Here are some factors to consider when picking the best windlass for your boat.

 

Does your boat already have a windlass you’re looking to replace?

If the boat didn’t have a windlass before, you’ll need to think about whether a manual, electric or hydraulic winch is right for your boat. By far the most popular type for recreational boats is electric. If you have a small boat and you would prefer supplying the power yourself, a manual winch may be a better option. If it’s a large vessel, you may be able to tap into hydraulic power the boat already has at its disposal.

 

Should you choose a horizontal or vertical windlass?

If you’re not sure which type you have, remember that the terms horizontal and vertical refer to the orientation of the shaft of the windlass. Another way of telling is to look at the chain wheel on the windlass. If it spins like a merry-go-round, it’s vertical; if it turns like a Ferris wheel, it’s horizontal.

The odds are you’re going to use the same type for your replacement, but if you had a vertical windlass, you can probably fit a new windlass that’s either vertical or horizontal. If you had a horizontal windlass, however, you’ll likely need to buy another horizontal one due to space constraints below the deck.

 

Were you satisfied with the windlass you’re replacing?

If your previous windlass worked well but wore out, you may have a simple decision to replace it with a similar model. But if it broke, or if you were dissatisfied with its performance for some reason, you should consider how another model or style might fit your boat better, or if the windlass was up to spec given the loads put on it.

 

Will a replacement windlass fit the cut-outs in the deck for a previous windlass?

If you were happy with your old windlass and are replacing it with the same brand, a “drop-in” installation will sometimes work. Occasionally, another brand can be fit without much additional deck work, but it is uncommon.

 

What’s the depth of your anchor locker?

Here’s a key measurement in all installations, whether replacement or first time. Keep it in mind when you choose and install your windlass and when you choose your anchor rode. When the rode is in the anchor locker, the top of the anchor rode should be a minimum of 16 inches below the underside of the deck, or you risk fouling the rode or jamming the windlass. The windlass should also be positioned so the chain or rope feeds through the deck plate, or hawsepipe, directly into the deepest section of the anchor locker.

Anchor Locker

Should you choose an all-chain or combo rope-chain rode?

Another critical decision is your choice of rode type and how it factors into whether a vertical or horizontal windlass will work best for you. As an example, most trawler owners lean toward all-chain rodes, which work well on either vertical or horizontal chain-wheels. On the vertical wheel (“merry-go-round style”), after the chain contacts the wheel on the starboard side, it will remain in contact for well over 200 degrees. On a “Ferris wheel” style horizontal chain wheel, the chain comes over the top of the wheel and then releases on the back side and drops toward the anchor locker after only 90 to 110 degrees of contact. Because the wheel is equipped with link pockets to grip the chain links, both orientations usually work well.

If a rope-chain rode is preferred, however, the difference between 100 and 200 degrees of wheel contact is crucial, because rope is more prone to slipping. We normally recommend a vertical windlass for a combined rope-chain rode. The chain wheels for rope-chain rodes have a V-groove below the link pockets to help hold the rope, and on a vertical windlass, you are more likely to find a spring-loaded pressure finger. This does nothing for the chain part of your rode, but where it transitions to a tapered splice, the finger pushes the splice into the chain wheel, allowing the V-groove to recover the rope more securely.

On a horizontal windlass, when the splice and rope begin coming over the top of the winch, there’s little engagement and it’s more likely to slip. Not only that, when the rope is slipping, it tends to wear faster.

 

Does the type and size of anchor chain affect your choice of windlass?

Galvanized chain comes in a variety of materials and link sizes, which must match the windlass. Also, look for chain with ISO-specifications (International Organization of Standards) rather than NACM (North American Chain Manufacturing). Most windlasses sold in the U.S. are designed to fit ISO chain.

Finally, there is stainless-steel chain, but beware, as it’s not all the same. Again look for ISO specs, and keep in mind that stainless is expensive and if you get the wrong size, it’s sometimes difficult to return.

 

Does the type and size of anchor rope affect your choice of windlass?

Yes, some windlass brands have models that manage both 3-strand rope and plaited-type rope, while others have models that only manage 3-strand. Also, every chain wheel will have rope diameter limitations. The manufacturers provide a range of suitable rope sizes a specific chain-wheel will manage. As the owner, you will make the choice based on several considerations: line strength as it relates to boat size, anchor locker size limitations, and the length required. Usually, the owner will select the largest diameter rope the chain wheel will manage.

 

If I have a rope-chain anchor rode, what type of rope is best on most windlasses?

If the anchor locker has suitable depth, a premium 3-strand nylon rope is suggested.  If the locker is on the smaller size or a large quantity of rope is required, then the plaited product may be better suited, as it is more malleable and can coil into smaller bundles.

 

What size and weight of ground tackle will you carry?

The size and weight of your ground tackle (rode plus anchor) are fundamental variables in choosing your anchor windlass. In terms of chain size, certain windlass models operate a range of chain diameters. For example, the Muir Cheetah horizontal windlass for yachts 38 to 45 feet offers chain-wheels for 5/16”-7/16” chain.

Assuming your boat is 30 feet long, here are two ways you could outfit the boat, resulting in different power requirements from your windlass. In both cases, we calculate maximum load on the windlass by multiplying the total weight by three.

 

Example 1:

100 feet x 3/8ths-inch chain = 150 pounds

Anchor = 60 pounds

Total weight = 210 pounds

Factor x 3 = 630 pounds
In this example, be certain the max pull of the windlass exceeds 630 pounds, and you’ll have power to spare.

 

Example 2:

20 feet x 3/8ths-inch chain = 30 pounds

180 feet x 5/8ths-inch 3-strand rope = 40 pounds

Anchor = 60 pounds

Total weight = 130 pounds

Factor x 3 = 390 pounds

In this example, if the max pull of the windlass exceeds 390 pounds, you’ll have power to spare. Be careful, though, because someday you may decide to change to an all-chain rode and you may need to upgrade to a model that can manage a heavier load.

 

Can you choose my windlass based on the size of your boat?

Manufacturers of windlasses provide guides based on boat length that will narrow down your choices. Below are sizing charts from four major windlass manufacturers. Actual selection should be made after reviewing your options with a competent marine consultant.

Lewmar:

Lewmar Chart

Lofrans:

Lofrans Chart

Muir:

Muir Chart

Maxwell:

Maxwell Chart

How much power does an anchor windlass need?

Your windlass is intended to lift the anchor and ground tackle, not pull or drag the boat. A typical rule of thumb is to take the total weight of your anchor plus complete anchor rode and multiply that by a factor of three to calculate maximum load the windlass may experience. This number should be less than the power rating of the windlass. As examples, Lofrans Project 500 and 1000 models have 1075-pound and 1500-pound power ratings, and the more powerful windlass would be needed for the example given in the previous question. However, there may be other factors to consider, and we strongly recommend that you consult marine professionals when determining what size windlass is right for your boat.

 

If the power rating represents maximum load, what percentage of that is a typical working load for an anchor windlass?

When looking at power ratings, the one-third factor applies. In simplest terms, for a windlass with a max load of 1500 pounds, ground tackle weight should be under 500 pounds.

 

At what angle should the rode approach a horizontal windlass?

The vertical angle of the rode when it contacts the windlass is usually more important with chain than with rope. When approaching the chain wheel, ideally the chain is parallel to the waterline or coming uphill, gaining a few degrees of engagement and perhaps half a link pocket of contact. That can make a difference. If the bow roller is higher than the winch, there will be less contact and the chain will be more prone to slipping. In those cases, we might recommend a vertical windlass or to mount the windlass on a riser box, giving it a bit more elevation.

Positioning the windlass chain-wheel on deck straight in line with the bow roller is ideal, which is why the base of the windlass is often set slightly off center-line. The lead angle to the windlass should in any case be within 5 degrees to port or starboard of the center of the bow roller.

Chain Angle

At what angle should the rode approach a vertical windlass?

The angle at which the anchor rode reaches the chainwheel on a vertical windlass is less critical since so much more of the wheel is in contact with the chain or rope. This means the height and pitch of the bow roller is more important to consider on a boat with a vertical windlass.

 

What should the proximity of the windlass be to the bow roller?

Usually the most important factor in positioning the windlass is simply to locate it over the deepest portion of locker to get the most drop. With depth, gravity is going to take the rode deeper into the locker.

 

What if the boat doesn’t have a bow roller?

If there was no windlass on the boat previously, there’s a good chance you’ll have to add a bow roller. How you will go about installing one will vary from boat to boat and may require modification if you have tall, or metal, toerails and need to mount a bow roller on top of the toerail, pass through the rail, or pass under it. At Imtra, we sell a line of bow rollers but we don’t do installations. Consult with boat manufacturers, boatyards and owners groups, and with luck you’ll find a similar or matching boat model that has already worked it out.

Sometimes adding a new bow roller is as simple as a bolt-on installation. Often, our customers add a bow roller and need to switch from a single red-and-green navigation light on the center-line to separate red and green lights to mount farther outboard.

Don’t forget that there is a selection process to obtaining the right bow roller, too. Your bow roller needs to be specific to the weight and type of anchor you choose so the anchor seats properly when raised.

Keep in mind the bow roller doesn’t have to be mounted exactly on centerline, although there should be no more than five degrees of deflection either left or right. In our experience, most bow rollers are mounted a bit to the left of center, which helps bypass a piece of deck hardware or the headstay fitting on a sailboat.

 

How do you match a windlass to your boat’s electrical system?

Assuming that you didn’t choose a manual windlass and you don’t have the option of utilizing hydraulic power by connecting up to your engine, you need to assess your electrical system, the size of your circuit breakers, and the gauge of your wiring. Each windlass model has a power wattage rating, and your batteries, wiring and circuit breakers must have the capacity to safely deliver that full motor current to the windlass.

There are many factors involved, including the wiring size, the distance it must run from battery to winch (round trip, to and from), and the resultant voltage drop (see ABYC 10% voltage drop table), and we recommend that you review with a professional in your decision-making.

 

How do you avoid an expensive electrical upgrade if you need a higher-wattage windlass?

Let’s say in your situation that given the weight of your chain and anchor, your ideal windlass would have a 1000-watt maximum load, but your electrical system is under-spec with 6 gauge wire and a 70-amp circuit breaker. The solution may be to compromise and choose a windlass with a 700-watt motor that only needs a 70-amp circuit breaker, then reduce the load on the windlass by using more rope and less chain.

 

For even more information on windlasses and anchoring products, check out Imtra’s anchoring catalog!

Written By John Burnham & Conrad Taylor

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