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Article by Tor Pinney                                                                                                                                        Back to List of Tor's Tips

                  

ATTENTION CRUISING SAILORS: THIS COULD SAVE YOUR LIFE!

 

CAPT'N TOR'S LAST CHANCE TRIP LINE
© 1990/2011 Tor Pinney - All Rights Reserved

 

Anyone who has ever sailed offshore shares a dread of falling overboard and helplessly watching the boat sail away. No matter how many shipmates you have resting down below, if you're alone on deck you're at risk just as much as the single-handed sailor. No one would hear you cry out.

Most passage-makers take the obvious precautions; maintaining pulpits and stanchions with continuous lifelines around the yacht's rail, and running jack lines along the side decks to clip on the safety harness that we wear most of the time. Some even tow a so-called "safety line" astern. Still, every so often we hear of the ultimate tragedy: Some sailor has fallen overboard and been lost at sea.

If you were to grab onto a simple "safety line" trailing behind a boat sailing at five or six knots, you'd have a tough time trying to haul yourself forward on it while being dragged through the water. Fully clothed, it would be virtually impossible. Eventually, you'd tire out and let go. But the result of grabbing the Last Chance Trip Line is that the boat will almost immediately come to a near or complete halt, giving the man overboard an opportunity to easily regain the ship. It will work aboard any boat, providing one last chance to save yourself if the nightmare ever comes true and you find yourself overboard and alone while underway.

The Last Chance Trip Line consists of about 200' of 1/2", yellow polypropylene line (i.e., floating line), a Styrofoam ball float, at least two 5-ft. pieces of 5/16" or 3/8" elastic shock cord with a plastic hook at one end, and one or two 1/2" blocks on lanyards. It'll also require a bit of trial-and-error experimentation because precisely how this equipment is assembled will vary from boat to boat.  Here's the basic idea:

The buoyant trip line, which has half hitches tied in every 6 feet or so for better gripping, trails behind the boat while voyaging offshore. The Styrofoam float marks the "bitter end.” The inboard end is led in such a way that increased drag on the trailing line will turn or disengage the self-steering mechanism or pull back the engine throttle. If the boat is sailing, she’ll head into the wind and stall. If motoring, she’ll stop.

The natural line tension created by towing the trip line is countered by the shock cord, hooked to a bight in the line a few feet abaft the stern rail, so that the inboard portion of the line remains just barely slack until the weight of a dragging person overcomes the shock cord to exert force on the inboard end. The barely-slack inboard end is led through blocks lashed with lanyards to exert either a pulling or lifting force when the line comes taut. Led to a throttle control, a windvane counterweight, an autopilot knob or a wire connected to a toggle switch, the line can be rigged to pull back or out or sideways to effect the necessary change. Run beneath a tiller pilot, it can lift it off its tiller pin. Because of the shock cord, the inboard end of the trip line remains slack (but just barely so!), exerting no force under normal towing conditions, but a person dragging on the line in the water will activate it instantly.

From an autopilot that’s steering while under sail, the line continues through a second block stationed to port or starboard of the helm, and then across to the wheel's rim (or tiller) in order to turn the boat to windward once it is pulled tight and the self-steering is disengaged. Led to a windvane,  it can simply yank the counterweight sideways to head the boat up.

On some boats a line-and-lanyard system might be easier to use. Tie a bight into the trip line where needed in the cockpit, anywhere between the side block and the shock cord's bight. Lanyards, or short lengths of shock cord, can be easily led off a bight to pull clutch knobs and switches. Whatever directional pull it takes for a trip line to disengage the self-steering unit and/or head your boat into the wind can be engineered with blocks, shock cords, lanyards and a bit of ingenuity.

When a boat's sailing speed increases, it may be necessary to adjust (tighten) the shock cord. Otherwise, the increased drag on the line could overcome the shock cord and trip the system. The tension of the shock cord is adjusted from the inboard end so that it continues to barely overcome the pulling force of the dragging trip line, but beware! Too short a shock cord will not have enough stretch left in it to allow the trip line to work when needed. It's generally better to re-tie the shock cord further forward on deck rather than to shorten it. If this still isn't enough to overcome the drag or if the shock cord is stretched nearly to its limit, then double up on the shock cord with a second one. Ultimately, the shock cord must absorb the towing force with elasticity to spare.

Your Last Chance Trip Line system is easy to test - without throwing your mate overboard. Just reach over the stern rail, beyond the shock cord, and haul firmly and steadily on the line. A safer alternative is to tie a bite in the line just abaft the shock cord attachment point, slide the end of a boat hook into it, and push to create the drag effect. If the ultimate result is that boat comes to a halt, you got it right.

Once the trip line has done its job and allowed the lone sailor to pull himself back to the boat, he still must be able to climb aboard unassisted. A permanent ladder or steps installed at the transom, or some certain means for a swimmer to pull down a stern boarding ladder, will ensure a happy ending to the man overboard self-rescue.

By the way, the polypropylene trip line should be stored out of the sun when not in use. Otherwise, it will deteriorate rapidly from exposure to ultra-violet rays.

 

The external autopilot on a sailboat's tiller (Figure 1) is the easiest to disengage - all it takes is a light lifting motion to jerk its drive arm off the tiller attachment knob. To do this, the inboard end of the trip line runs from the bight (a) to which the shock cord (b) is attached, over the pushpit rail (c) to give it some height, then through a block (d) lashed to the tiller immediately aft of the attachment point of the autopilot drive arm. The block hangs by its lanyard just a few inches below the tiller. Finally, the trip line runs across the cockpit and slightly forward to the lee rail where it is tied to a strong attachment point (e) which is only slightly higher than the tiller. This end is secured, taking up almost all of the  slack in the trip line, but still allowing the shock cord to take the entire pulling force of the line trailing aft. 

Because of the shock cord, the inboard end of the line remains slack (but just barely so!), exerting no force on the autopilot or the tiller. But if someone in the water were to grab that trip line and drag behind the boat on it, the increased line tension would stretch the shock cord, putting tension directly on the trip line inboard of the bight. The taut trip line will raise the block, lifting the autopilot drive arm off the tiller, and it will simultaneously pull the tiller to leeward. The boat will head up, luff the sails, and stall. If the jib is trimmed for windward sailing, it will likely back, heaving the boat to. If the sails are trimmed for a reach, they'll likely continue luffing even it the boat falls off again. In any case, the man overboard has time to pull himself easily to the stalled boat. 

Disengaging autopilots on boats with wheel steering requires variations of this principle, depending on the autopilot system used and how it is installed. (See Figure 2) It may be necessary to run the trip line through a block on a short lanyard (a) tied to the autopilot's clutch knob so that it will, under tension, pull out the knob to disengage the self steering. The same principle applies to both wheel-hub clutches and to foot-level clutches such as the popular Autohelm and Navico units. From the clutch block, the line passes through a second block (b) stationed to port or starboard of the helm, and then across to the wheel's rim (c) in order to have the ability to turn the boat. If the second block is on the lee side of the cockpit, the line's attachment point along the rim will be at the farthest (windward) spoke BELOW the wheel's horizontal center plane. If the block is on the windward side, the line must be led to pull on the farthest (leeward) HIGH spoke (as illustrated in Figure 2) in order to turn the boat into the wind. Again, the shock cord aft holds the inboard line section barely slack until a strong pulling force is applied to the outboard end of the trip line.

On some boats a line-and-lanyard system might be easier to use (Figure 3). Simply tie a second bight into the trip line, anywhere between the side block and the shock cord's bight. Lanyards, or short lengths of shock cord, can be easily led off a bight to pull clutch knobs and switches. Whatever directional pull it takes for a trip line to disengage the self-steering unit and/or head your boat into the wind can be engineered with blocks, shock cords, lanyards and a bit of ingenuity.

With internal autopilot units, a lanyard coming off the trip line may be led so that it flips a toggle switch that turns off the unit, allowing the trip line to turn the helm. Better still, a tug on the trip line could be rigged to activate an electric over-ride switch that will cause the autopilot to steer the boat sharply to windward. The same switch could also activate an alarm to arouse sleeping crew. But keeping it simple and self-reliant is probably best.

Windvanes pose no problem once you grasp the general idea of the Last Chance Trip Line. But rather than disengaging the windvane, the trick here may be to use it to steer the boat into the wind.

On a Monitor windvane (Figure 4), the trip line passes first through a block on a lanyard (a), then between the rods holding the vane's lead counterweight which is below the wind paddle (b), and finally ties to a convenient part of the windvane's framework (c) or ship's hardware. Once again, the shock cord (d) is attached to the trip line at the outboard bight, in this case just aft of the block. Because the shock cord keeps tension off the inboard section of the line, the windvane is free to operate unimpeded - until someone pulls on the trip line. Then the cocked windvane will steer the boat up into the wind, stalling her. By having the block on a lanyard, it's easy to shift its position and experiment to determine the correct angle of pull on the windvane's counterweight. This changes as the windvane paddle is swiveled for different points of sail. In this manner, you control which way the windvane will turn the boat when the trip line is pulled.

Lastly, stopping a boat that is motoring is as simple as rigging the line or lanyard to pull back the throttle, or the throttle and gear shift levers, or the engine cut-off knob. After reviewing the above variations of leading and balancing the trip line, an engine-stopper should be easy to figure out aboard your own boat.

You might argue that at night the trip line could be difficult to find quickly enough for a frightened person grappling in the dark, or that it's useless to an unconscious man overboard. You can also insist that nothing takes the place of exercising proper caution to ensure that crewmembers don't fall off the boat in the first place. You'd be right. The Last Chance Trip Line is no substitute for wearing your safety harness while on deck, nor is it a 100% guaranteed lifesaver in every situation. But for the lone mariner who suddenly finds himself overboard while the boat sails on without him, the Last Chance Trip Line is a whole lot better than the alternative - no chance at all.

~ End ~

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