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November Cruising Tip

Posted by on November 4, 2014

One of our newsletter readers, in a comment on this website, asked for details of how we rigged the gantline we use for going aloft. Herewith a short excerpt from Safety Aloft, which I think is one of the more important chapters in the 3rd edition of The Capable Cruiser. 

A proper gantline is essential for both long-distance racing and offshore cruising unless you always sail with a large, strong crew. If you have a varnished or painted spar it is even more important. A gantline is simply a four-part block and tackle arrangement that lets you haul yourself aloft with relative ease. We use two neoprene shelled double blocks[1] (one with a becket) a 250-foot long 1/2-inch line (the same one we use as a stern anchor line) plus a galvanized hook for this purpose. This makes a gantline sufficient for work on any mast up to 47-feet tall. If we put a tail on the warping line we could stretch the gantline to work on spars up to 52-feet tall.


When it is time to use the gantline we secure the double becket block directly to our halyard using a bowline with a long tail. For security we tuck the tail through a lay in the line. The other double block is secured to the chair (figure 19.3). Then we feed the line through the blocks as we haul the gantline aloft until it is snug against the masthead and we secure its end to our anchor windlass. (This keeps the secured line away from the spar while we varnish. The four 1/2-inch bolts holding the windlass in place will definitely make anyone in the chair feel well supported.) It’s amazing to see how versatile this rig is. Because it increases your pulling power by four, you can pull yourself up the mast. (Even I can do it alone.) If you add a galvanized hook (or a small cleat) to the shackle on your chair, you can be in complete control of your assent or descent. Simply take three turns around the hook with the tail line of the gantline and the weight and friction of the line will hold you right in place where you want to work. Ease the line, you’ll slide slowly down the mast, haul on it, up you’ll go. This gantline leaves your deckbound assistant free to get you the parts you need.

Here is our bosun’s chair, set up and ready to go aloft.

Here is our bosun’s chair, set up and ready to go aloft.

If you plan to work aloft on a complex job, it pays to rig a messenger line with a bucket so you can have your assistant send you that special screw driver or seizing wire. In our case when Larry is working on the varnish and has to be aloft for three or four hours at a time, we use the messenger bucket to send up a light lunch so he doesn’t have to come down until he has finished varnishing. A spare halyard or the hauling line on the gantline will usually work for this job.

You can see the details of how we rig the chair to the gantline

You can see the details of how we rig the chair to the gantline

Mast steps are one piece of equipment we definitely do not recommend. They are bulky and unsightly. They snag halyards and chafe at sails. Their increased windage causes boats to wander at anchor and wind whistling through the steps can cause nerve-wracking whines in heavy winds. Worse yet, because they are so easy to use, mast steps are often the cause of accidents…. going aloft can be dangerous and must be taken seriously. If you have to prepare and check your gear each time you head up the mast, chances are your subconscious mind will get the message and keep you acting carefully each step of the way.

[1] The neoprene shells are soft and have well rounded edges to prevent dinging or scratching the spar.

Notice that Larry has a safety line from the chair and then around the mast.

Notice that Larry has a safety line from the chair and then around the mast.

One Response to November Cruising Tip

  1. SunriseBoy

    When I see someone do this kind of thing I know why I’d never succeed in cruising. I struggle with a reef-knot let alone the intricacies of a rig like this.

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