DISCLAIMER: Although we will try to cover most aspects regarding halyard wraps, remember this is a written article, and it is impossible to address every possible nuance and potential cause of these issues. It is always best to contact your local friendly yacht rigging service if you have any doubts as to how to deal with halyard wraps.
In this post we will discuss some of the common causes of halyard wrap, how to spot them, and how to make sure they don’t happen again!
What is a halyard wrap? When furling or unfurling a roller furling headsail, the halyard should never wrap itself around the forestay. If this occurs, you have just experienced a halyard wrap! You will instantly know you have a problem because the furler will appear to jam.
To put this very simply: When the furler rotates, the halyard should not also rotate with it.
By far the most common causes (in our experience) of halyard wraps is a combination of poor halyard lead angle (the angle that the halyard makes when it exits the sheave box and runs to the top furler swivel), failing or dirty upper swivel bearings, or halyard tension – too much OR too little!
What is supposed to occur when furling and unfurling is that the halyard swivel allows the furler to spin, unrolling or rolling up the sail, while at the same time allowing the halyard attachment point, or top half of the swivel, to remain static. Most roller furling manufacturers recommend that there is a lead angle of greater than 7˚ between the halyard and the furler extrusions/forestay. If the manufacturer does not require this angle they install some kind of wrap preventer that is fixed to the forestay wire directly above the foil that (in theory) prevents the halyard from passing around the forestay wire. With poor halyard tension, or poor swivel condition, wraps can still occur to these systems.
To create the 7˚ lead angle one usually has to install a halyard restrainer of some kind. Several manufacturers produce these, including Selden, Harken, Schaefer, and more. The restrainer is mounted directly to the mast a few inches (depending on the situation) below the halyard exit point and the halyard is routed through it before attaching the halyard to the top furling swivel. The restrainer deflects the halyard downwards and then outwards towards the foil at an angle that makes it almost impossible for a wrap to occur, provided enough halyard tension is applied to prevent slack up top. Even with the halyard under tensioned a good lead angle is usually sufficient to prevent wraps occurring
Another potentially cheaper or easier way to create this 7˚ angle is to install a short pennant or strop at the tack of the sail, allowing the swivel to sit higher up on the furler – but do not let it ride up onto the very top of the furler extrusions! This will cause other serious and expensive issues. This solution only works if your sail is a little bit too short, and if the halyard exit box or sheave is positioned on the mast in such a way that a fully hoisted halyard swivel will create that angle we talked about above.
Profurl furlers have a black plastic “wrap preventer” attached to the forestay wire, this must be tightly clamped to the wire so that it does not simply spin around when the halyard (or stainless extension arm of the swivel) comes up against it. There are written instructions with these parts, follow them closely or they will not clamp tightly enough to the wire to be effective. Once they are worn out, replace them.
Facnor furlers have a large plastic black round disc that sits on top of the furler extrusions – and this one rotates on the wire. The idea with it is that the width of the rotating disc will prevent wraps from occurring.
On halyard tension: When hoisting your headsail make sure to put adequate tension on the headsail, enough to maintain good luff shape. Check the luff to make sure it’s nice and snug. If you are adjusting halyard tension whilst sailing, make sure to check the halyard tension before furling, having the halyard too loose can create enough slack for wraps to occur, and having the halyard too tight can put too much pressure on the swivel bearings and cause it to freeze up, which will also result in wraps occuring.
An occasional cause of halyard wrap is a sail luff that is simply too long for the furler, thereby making it impossible to get adequate halyard (or luff) tension and most likely pulling the top swivel over the top of the foil. This is bad for several reasons. You should be able to see at least 1″ of foil sticking up above the top swivel with the sail fully hoisted. If you can’t, you need to have your sail shortened appropriately.
How to diagnose the problem: This one is simple. If your furler is “jamming” or requires you to release a little and then furl some more in order to free it up, you most likely have a halyard wrap occurring. How to be sure? Break out the binocs or cast your eyes aloft whilst this jamming is occurring and watch the halyard. You will see it wrap around the top of the foil or forestay while someone is attempting to furl or unfurl it.
DO NOT PUT THE FURLING LINE ON THE WINCH IN A JAM. EVER! This is a wonderful way to break your forestay and potentially bring your mast down. If you are stuck out in a blow and can’t seem to get the sail to furl, turn downwind if you safely can, depower, let it flog a little, and keep trying. If it will completely unfurl but not furl up, unfurl it and drop the sail on the deck and figure out the problem back at the dock. Winching it while a wrap is occurring is not going to help. At all.
Worst case, if a bad wrap has jammed everything and the sail is partly furled, obviously you can’t drop the sail, so remove the sheets and manually pass the sail around and around the foil to get it as under control as possible (this is only really feasible on smaller boats). If conditions allow: send someone aloft to try and free the wrap. Find a way to get the sail under control and lashed down that doesn’t involve pulling harder and harder on the furling line.
A final word of warning: If you have been experiencing halyard wraps, and know that someone has attempted to winch the furling line to get it to furl, or that brute strong friend of yours has heaved on it with all their might during a jam. Have a rigger go aloft (or you go aloft) and inspect the forestay at the masthead. There is a strong chance that the twisting tension on the forestay has damaged it. Look for wires that appear to be unraveled or even broken. This is VERY SERIOUS. You need a new forestay. Do not sail until one has been installed.
If you have any questions or comments we’d love to hear them.
