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.
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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.
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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.
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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.
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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.
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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.
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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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