Installing a Windlass

Installing a Windlass

If you’ve had enough of pulling an anchor up by hand, and decided that a windlass is the way forward, then read our handy guide on how to install a windlass. We’ve broken it down in to relatively straight-forward steps, starting with what type of windlass to choose in the first place...


Type of Windlass


Once you’ve decided that you need a windlass, the next choice is what type of windlass to buy. This is normally dictated by the type of boat you have, the space available for installation, and how competent you are with the work itself. Windlasses are essentially available in two varieties - horizontal and vertical. This describes the axis around which the unit rotates, so a horizontal windlass has its gypsy (the cog that the chain is held by) on the side, and its axle is horizontal just like a car tire. A vertical windlass, as the name suggests, has a vertical axle, and the gypsy is on the top and rotates like a record player. We’ve put a pair of images below to make this clearer.

Types of Windlass

Both work the same way, but the vertical type has a motor that sits below the deck, whereas the horizontal type has a motor that sits above the deck in a casing. In fact, the horizontal type are completely enclosed, making them the preferred choice for DIY installation, but ultimately it depends on how much space you have below the deck (and above it). If you have a large anchor locker that can accommodate the windlass motor in addition to the chain then choose a vertical windlass. If your anchor locker is only just big enough for you chain, then choose a vertical windlass and everything will sit above deck. 


As we touched on above, it’s also worth noting that the vertical windlass has a motor below deck, and a gypsy above the deck. The deck itself is therefore sandwiched between these two units, making installation a little trickier, so bare this in mind. 


Windlass Power


Both horizontal and vertical windlasses are available in a variety of power outputs to suit different sizes of boat. This is normally measured in the number of watts that the motor consumes, but some manufacturers use the pulling power instead, so just make sure that you follow the manufacturer's guidelines when choosing the power required for your size of boat. And don’t necessarily assume that because the windlass you are looking at is model ‘1000’ that it is a 1000w windlass. We’ve put a rough guide below as to how many watts you will probably need for certain sizes of vessel, but as above make sure you check the manufacturers specs before making a final decision. You will see a certain amount of overlap between sizes, and this takes into account boat weight and windage, so if you have a heavy boat or a large flybridge, it may be worth erring on the side of caution and choosing a more powerful windlass.

  • Boats 18-25ft ---------- 300w
  • Boats 23-30ft ---------- 500w 
  • Boats 28-38ft ---------- 700w 
  • Boats 36-43ft ---------- 1000w
  • Boats 40-48ft ---------- 1500w
  • Boats 46-60ft ---------- 2000w


Planning your Installation


When planning your installation, you will need to take in to account several things, and we’ll go through them step by step to keep it reasonably logical.

Deck Strength, Location and Chain Drop.


The windlass will ideally need to be mounted over a reasonably deep area of the anchor locker, and the chain should drop pretty much straight down. In our experience trying to route the chain down through pipes or at an angle is often risky, and it’s well worth shopping around for a different windlass type to make sure you can get the ‘drop’ in the right place. This should idctate the ‘zone’ in to which you will be able to mount your windlass, and now it’s time to look at this area in more detail. Is the deck flat? Is the deck strong enough? Is there a door to the anchor locker in the way? If the deck isn’t flat you will probably need to make a shim or plate - the windlass will be very securely fixed down so if the deck is bent this could be damaged as the fastenings are tightened. Check the strength of the deck, is it reinforced? If in doubt you may need to reinforce yourself by glassing in a backing sheet or having a metal plate made to distribute the load on the underside of the deck over a larger area. Pay attention to the height difference between the bow roller (more on these later) and the windlass too, the chain shouldn’t enter the gypsy of a vertical windlass at more than a few degrees off dead straight. Horizontal windlasses are a little more forgiving in this respect, but even so the chain angle shouldn’t be more than 10 degrees or so of the horizontal as the gypsy needs a good grip. 


Power Supply

Windlass Wiring

Getting power to the windlass is not quite as difficult as it once was, but still needs to be factored in. Modern windlasses use very efficient motors, so don’t need quite as much power as they once did. This means that you don’t necessarily need a separate battery at the front of the boat, particularly on sub 700w windlasses. The location of your batteries within your boat can play a big part in this too, as the longer the cable run between the battery and the windlass, the larger the cables can be. Most windlass manufacturers publish a cable size guide, which will give you the exact cable size you require, but below is a rough guide to get you going:

  • 300w - 0-15m 10mm2 Cable Required
  • 500w - 0-7m 10mm2 Cable Required - 7-15m 16mm2 Cable Required
  • 700w - 0-7m 16mm2 Cable Required - 7-15m  25mm2 Cable Required
  • 1000w - 0-15m 25mm2 Cable Required - 15-24m  35mm2 Cable Required

Generally anything larger than 1000w will need a battery to be placed near the windlass in the bow of the boat, but smaller cables will still need to be run forward to charge this battery. 



Windlass Switches

How you wish to control the windlass is of less importance at this stage, but if you are running battery cables it’s well worth running smaller control cables at the same time. Most windlasses are controlled by a solenoid switch or ‘contacter box’. This is normally supplied with the windlass. These solenoid switches control the current flowing in the windlass, and are in turn controlled by smaller switches that we press to activate the windlass. The three main types of switches are foot switches (located on the deck near to the windlass), toggle switches (normally located near the helm) and a wired handheld remote (plugs in when you want to use the windlass). You can add as many switches to a windlass as you like, and we often recommend fitting a combination of the above so you can control the windlass from different places. It’s no good having foot switches at the bow if you often use the boat single handed, and conversely a toggle switch at the helm can be frustrating when the person on the bow has far better visibility of the situation. 




Windlasses are available with different sized ‘Gypsy’ units to fit different sizes of chain. It’s important to either buy a windlass that fits your chain, or to budget for new chain if the chain you have is either wrong or not calibrated for use with a windlass. Chain is available in various calibrations too, but DIN766 and ISO are by far the two most common, and actually in smaller sizes they are so similar that a gypsy can be built to fit both. Chain is measured in milimetres, and this is the ‘thickness’ of the metal that is then bent around to make a link. We’ve put a rough guide to chain sizing below, but chain sizing is open to interpretation somewhat, and it’s worth speaking to other people with similar boats before making a decision.

  • 6mm Chain - Boats 18-25ft
  • 8mm Chain - Boats 25-36ft
  • 10mm Chain - Boats 36-48ft
  • 12mm Chain - Boats 45-60ft 

Anchor & Bow Roller


Windlasses will work with most types of anchor, but it’s worth checking that your anchor is ‘self launching’. This means that when sat in a horizontal bow roller, the anchor will self launch once the chain is slackened off by paying out chain using the windlass. This can be a great asset if you are sailing short handed and wish to launch the anchor from the helm or cockpit - you semply press the ‘down’ button and the anchor will launch itself. Non self launching anchors require a shove to get them over the front of the boat. Popular types of self launching anchor include the Delta, Rocna, Manson and Spade. Bruce and CQR anchors generally don’t self-launch, but can if the bow roller is tilted forward, so check your individual setup. Your bow roller should be strong and well fixed, as when the anchor is pulled up and the chain becomes taught it can put quite a large force on the bow roller

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