How to Replace Halyard Rope

Item # X-HT-300072
Replace your halyard line without climbing the mast following this how-to video

Your boat’s halyard lines are exposed to harsh weather conditions and near-constant handling, so after years of use they will start to wear out. If your halyards are showing signs of wear and tear, it may be time to replace them. Replacing a halyard line can be a delicate process, but it’s really pretty simple to do. We’re going to show you how to replace the line for a mainsail halyard with the mast up, and without climbing the mast.

To see this process in action, watch Matt Grant install new halyard line on our Seaward 24 Project Boat in this video.

Select Your Replacement Rope

First, you’ll need to decide which type of rope to use for your halyard. We used 5/16-inch Sta-Set from New England Ropes for our Seaward 24, because we wanted a very low stretch line. New England Ropes Sta-Set is a great choice for a weekend cruising boat like ours. If you want to learn more about rope selection, check our post "How to Select Rope for Your Boat" (#300082XHT).

Measure Length of Rope Needed

You can refer to your boat’s owners’ manual to determine the length of halyard rope needed, if it’s available. If not, you’ll have to measure the height of your mast. An easy way to do this is to attach a metal tape measure with a loop end to the shackle at the end of your halyard line. Then raise the halyard to the top of the mast and note the measurement of the mast at the mast step. That’s your mast height.

To determine the length of your halyard, pull the halyard so the shackle is down to the mast step. Now your length of line along and inside the mast is equal to 2 times the mast height. Then, measure the segments of line between turning points and to the end of the line. Add all these measurements together and that’s the total length of line.

Sew the Ropes Together

Untie the shackle from the old halyard and use a bowline knot to attach it to one free end of the new halyard line. Then, take the other free end of the new line and butt it up against the old halyard line’s end (that previously held the shackle). To replace the line, you want to feed the two lines secured together up the mast. So the lines don’t separate, it’s important to make sure you connect them strongly. To do that, we suggest sewing and whipping the two lines together with waxed twine. It doesn’t matter how you connect the lines exactly, as long as they are secure. We do not recommend using only tape, however.

Pull the Ropes Up

Send your new halyard rope up and through the mast by raising your existing halyard line. Be sure to straighten out any kinks in the rope as you pull up the new line. If you feel any resistance while pulling, slowly back up and pull gently again so as not to disconnect your new and old lines. When your line is pulled all the way through, use a hotknife to cut off the old line, just past the butt joint. Run the line through your cleat and tie a figure-eight knot to finish it off.

Do you have any helpful tricks for replacing your halyard lines? Share them with us in the comments!