Like the automobile safety belt, the various components that keep sailors from separating from their boat (the harness, tether, and jackline) have gone through significant changes over the years. If you search the Practical Sailor website under these topics, you’ll find a number of reports on the recent changes in this equipment. One element, however, that has not addressed in great depth is the proper placement of jacklines (also called jackstays).
Vendors of pre-made jacklines offer some guidance on installation, but typically it is left up to the sailor to decide where they will fit best. The result is that most jackline systems are afterthoughts and many are poorly engineered. In some cases, amateur hardware installations can lead to expensive deck repair work down the road.
World Sailing, the governing body for international sailing, gives load specifications for jacklines and for fixed clip-in points. It offers general advice on placement, advocating fixed clip-in points at most works stations, such as the helm and winches (see adjacent story). But that’s about it for advice. In this report well explore the placement problem in more detail, dispel some common misconceptions, and offer some tips on ways you can save time and money installing your own jackstay system.
Trial Run
The problem with early 1970s car seatbelts was not that they weren’t safe, its that they weren’t usable. They were not self-retracting and lacked an inertial lock, so they needed to be left loose if you wanted to move.
For jacklines to be effective they need to be as user-friendly as seatbelts, not slowing the work and not adding tripping or tangling problems. They must not interfere with running rigging-typically passing under sheet-leads, but over most other running rigging. They must not be underfoot and they must not create a tripping hazard. They must be easy to pick up (webbing often sticks to the deck) and easily identified as different from running rigging, even in the dark. Some new jacklines, like those from Wichard, glow in the dark. You can also use glow-in-the-dark tape to mark the jackline at intervals.
You must learn where to stand during certain activities so that the tether does not foul something. We recommend test-fitting lines using surplus polyester double-braid or its equivalent. Sail with them in place for a dozen fair weather outings before you settle on a design. Make sure to change sails, set anchors, and carry out all the normal on board activities. You might be surprised by what you find.
In a perfect world, boats would have jacklines permanently installed. You don’t want to be running around the deck installing your jacklines after the conditions have deteriorated enough to warrant them. Although you can use your existing cleats and strong points to attach your jacklines, this can interfere with using these cleats-and the cleats might not be located in the best spot. On many boats, separate anchors are preferable, and these must meet the 4,500-pound World Sailing minimum strength requirement (see PS, November 2015 online). Another option is to integrate a padeye into existing hardware (see adjacent photos) so you don’t have to drill new holes.
Side Deck vs. Centerline
Traditionally, jacklines are run from bow cleat to stern cleat along the side decks. Unless there is a specific reason to walk on the leeward side-and this is rare-all work is done on the windward side. What if you’re forced to work on the leeward side? The standard approach is to attach to the windward tether-often a complicated maneuver-so there’s no way to slide off a heeled deck.
This brings up toerail and handrails. Many boats have undersized toe rails that will not give you much to put a foot on as you slide downhill. World Sailing regulation only requires one-inch toerail and only forward of the mast. There is no handrail requirement-but most cruising boats have at least a pair of handrails between the cockpit and the mast.
A recent fashion is to run jacklines near the center of the deck. Sometimes these originate near the cockpit, allowing the sailor to clip on there and pass on either side of the mast, terminating near the bow. Sometimes there are separate sections, running from the corners of the dodger to the mast, and from there to the bow. A harness with two tethers allows you to clip-in one tether before unclipping the other.
Although two or more jacklines with a split at the mast will require additional clipping and unclipping as you pass the mast, most of the time when sailors go on deck in rough weather they are going no farther forward than the mast. The obvious vulnerability is that when the boat is heeling strongly, a centerline jackline is much closer to the leeward rail and sliding overboard is much more likely. In fact, on smaller boats, a centerline jackline position offers precious little security sailing to windward.
While there is a strong argument for an uninterrupted run from the cockpit to the bow, it isn’t necessary for the jackline itself to go all the way to the bow. If you are working on or near the forestay, there’s no reason you can’t clip one leg of a two-leg tether to existing hardware, leaving the longer tether leg on the jackline. Having this longer tether clipped aft reduces the chance of being thrown forward if the boat stalls.
Multihulls vs. Monohulls
Multihulls move differently and don’t heel, so the ideal jackline installation will be different than it is for multihulls.
Given the increased beam, the jacklines can be safely located at least 3- to 4-feet inboard. This is important because although it is difficult to fall to windward from the side deck of a heeled monohull, the quick side-to-side whipping motion of a catamaran in a beam sea makes it quite possible.
While the mass of a monohull tends to drive it forward and through waves, multihulls have a tendency to stop when the front beam plows into a wave. It is common to be thrown considerable distances forward. Thus, the jackline should terminate no less than 4 feet from the forward beam. Longer-than-standard tethers can be quite handy on a multihull, and if these tethers are in use the jackline should terminate even farther aft of the bow.
In multihull in heavy seas, it is not unusual to have your feet float up from the deck, and for you to experience negative gravity-a consequence of high speed, light weight, and steep seas. The solution is to stay low while working (sit or kneel on two knee pads) and to clip to something low, often the trampoline lacing. This is a secondary clipping point, with longer leg still on the jackline.
Because cabin tops on catamarans are often high and broad, a fall will throw you clear over the lifeline. The motion of a catamaran is at its worst high above the water line and forward. Some manner of cabin top jackline or clipping point is prudent.
Similarly, because of the width at the stern, a dedicated stern jackline, at least 4 feet forward of the stern may be called for on certain cats and many trimarans. For most catamarans, a few hard points are adequate and will create less clutter.
Recommendations
Every boat has unique deck and rigging geometry, so our examples are suggestions. The most important thing is that it is useable and that it fits the purpose. Some things to consider:
Separate jackline anchor points. These must be minimum 4,500-pound fittings. Advantages are permanent installation and flexibility.
Side jacklines supplemented with center jacklines and hard points.
Use hard points, short jacklines, and double-legged tethers to solve workstation problems; only one or two sailors should be on the jackline at any time.
Cabin top is preferred when possible. This gets the lines out from underfoot, encouraging permanent installation. Additionally, it allows the use of more durable materials such as rope and steel cable.
If you have a tip for routing jacklines, wed be interested in hearing from you at practicalsailor@belvoir.com.
World Sailing (formerly International Sailing Federation), the world governing body for the sport of sailing, has established clear guidelines for clipping in points on boats participating in events sanctioned by World Sailing
Jackstays shall be made of stainless-steel 1 x 19 wire of minimum diameter 5 millimeters (3/16 inches), high-modulus polyethylene rope (such as Dyneema/Spectra), or webbing of equivalent breaking strength (minimum 4,500 pounds). Any stainless-steel wire shall be uncoated.
Clipping points shall be provided attached to through-bolted or welded deckplates or other suitable and strong anchorage points adjacent to stations such as the helm, sheet winches and masts, where crewmembers work for long periods; which, together with jackstays and static safety lines shall enable a crew member to clip on before coming on deck and unclip after going below. While clipped on crew should be able to move readily between the working areas on deck and the cockpit(s) with the minimum of clipping and unclipping. You should have enough clip in points so that two-thirds of the crew can simultaneous clip without depending on jackstays.
