Whether made of wire, rope, or webbing, a good jackline system provides a secure, convenient, and continuous means of attachment for safety harness tethers while crew members are on deck. As your life may depend on a jackline keeping you aboard, it should be made of strong and lowstretch material, be kept as taut as possible, and be routed inside the shrouds down both sides of the deck as close to the centerline as possible.
Ideally, jacklines would be located to allow a harnessed and tethered crew to reach the rail, but not beyond. Once a crew goes over the lifelines and into the water, recovery becomes vastly more difficult. It is always good practice to clip onto the windward side jackline to minimize the chances of going over the side.
Because jacklines attract dirt and grime, are subject to UV degradation, abrasion, and chafe, and can provide a potential ankle-spraining hazard, offshore cruisers and racers wisely remove their jackline systems when not in use.
Jacklines can be secured to the boat at most strong and through-bolted attachment points such as the stem head fitting, mooring cleats, windlass, U-bolts, and padeyes. Using lifelines as jacklines is not recommended due to the necessity of frequent clipping and unclipping of the tether hook while passing stanchions. Lifelines used as jacklines are also too close to the rail of the boat for safety. In the event of crew being launched overboard by an off-balance fall or breaking wave, a tether clipped to a lifeline would likely break off the stanchion, uproot the stanchion base, or otherwise damage the lifeline system, making man-overboard recovery even more difficult.
An excellent method to terminate the aft end of a jackline is to lash it to a padeye. Lashing allows adjustment and tensioning of the jackline, as well as easy removal. A valid argument can be made that jacklines should end 6 to 8 feet forward of the stern so a man-overboard cannot be dragged and drowned behind the boat.
For more advice and recommendations on the best ways to stay aboard in all conditions, purchase and download MOB Prevention & Recovery today!
