Anchor windlasses let out and retrieve anchors. A windlass manages the rode (chain and/or rope) which attaches the anchor to the bitter end of the hull. The windlass neatly dispenses out and draws back in the rode. The bitter end is a fixture in the forward chain locker. The rode attaches one end to the fixture and travels up through a spill hole, hawser hole, up to the windlass. The rode then wraps around the wheel of the windlass. The wheel is known as variously: gypsy, wildcat, chainwheel, or warping head. The wheel engages the rode for letting out and drawing in. Finally, the rode goes out the windlass wheel, over the bow roller, and attaches to the anchor. The windlass wheel can orient horizontally or vertically. The horizontal way is called a windlass, the vertical a capstan. We assume the windlass as electrically powered.
The traditional horizontal windlass is simple. The wheel, gearbox, and motor are all on deck. All the parts are right there for maintenance making work simple. Every piece is out in the open and enclosed in one protected manifold. Installing means just screwing the windlass down in a good spot over the chain locker with a spill hole for the rode. The chain flows naturally off the horizontal wheel and down the hole with the same compass and angle. The lines flow without kinking or jamming. An nice extra is the ability to have dual wheels. A horizontal windlass can maintain a wheel one each side for a double bow roller set up.
A capstan like a winch rotates around a vertical axis freeing up space. The gearbox and motor are below deck while the wheel pokes above. Most of the windlass is below deck, safe and invisible. The capstan is free laterally. The capstan feeds out the rode without a dedicated angle. The bow roller and capstan can offset any different directions. They are not necessarily in line or centerline. A side benefit is a lower center of gravity. With the bulk of the parts below deck, the boat may go faster and stabler through the water. The parts solidify the boat’s performance.
Two types of windlass are vertical and horizontal (capstan). A windlass can also power by manual and hydraulics in addition to electrical. A windlass is a must have for large boats and rough seas. The windlass capacity should be three times the weight of the anchor plus rode. For example, a 40′ boat might have a 50 pound anchor plus 200 feet of 3/8″ chain (156 pounds per 100 feet). That is ~350 pounds. The windlass capacity would be 3 x 350 ~= 1,000 pounds. Prices range from $500 for a 500 pound windlass to $5,000 for a 3,000 pounder with double wheels. Price are the same for corresponding capacity horizontal and vertical types. Maxwell and Lewmar are two dominant brands. IDEAL is another good one.