From: amirza@bronze.ucs.indiana.edu (Anmar Caves)
Subject: Re: Tow chains or slings?
Organization: Indiana University
Date: Sun, 13 Dec 1992 18:19:28 GMT

In article <122980020@hpfcso.FC.HP.COM> byrnes@hpfcso.FC.HP.COM (John Byrnes) writes:
>> 
>> I just took delivery of my new 4X4 sport utility vehicle. I want to
>> get a chain or nylon tow strap to use to pull somebody out of a ditch
>> if necessary.
>> 

I have a lot of experience winching, towing, or generally extricating
cars, trucks, stumps, people, what have you.

Regarding the below note about retired dynamic rope, few points before
I get on to the serious stuff. 
There is a reason why old climbing ropes are retired even though they 
may look ok.  Second point.  Stay away from using dynamic
climbing ropes for long pulls in vehicle extrication.  They can
stretch up to 30% before breaking, and that's a hell of a lot of
energy to store in a rope.  If your pull is longer than 20 feet or so,
use a static rope such as PMI maxiwear or similar.  Static ropes will
typically stretch only a few percent before breakage.  This will give
you less a rebound should the rope snap.  

ONE FINAL CAUTION:  DON'T FOR ANY REASON USE A CLIMBING/CAVING ROPE
THAT HAS BEEN USED TO EXTRICATE A VEHICLE IN A LIFESUPPORTING MANNER.
Make damn sure no one will ever use it for lifesupport.

Having said that I'll go on to serious vehicle extrication stuff.

First thing I did right after the first time I had to pay a tow truck
$55 to unstuck my vehicle was to run right out and buy a LugAll (tm)
2000# single pull come-along.  This came with a pulley and hook for
doubling, effectively giving me a 4000# maximum pull.  This brand of
come-along is one of the best currently made.  Buy an extra handle for
it.  The handle is designed to be the weak point in the system and
will bend before anything else breaks.  I then bought a 20' 20k# tow
strap and a 30' section of chain with a hook on one end and a link
hook on the other end.  I generally used the chain as the anchor point
on the trees or rocks (always pad the trees! Old carpet sections work
well for that) and the tow strap doubled.  The tow strap would be
wrapped around the frame member and both hook ends brought out to be
worked with the hook from the come-along.  
Now I have a 50', and a 100' section of some of my old static 11mm
caving rope.  It's been marked clearly as NLS (not for life-support),
and only leaves the truck when it's being used.  I retired the chain,
chains are far too heavy to use for the strength.  The tow strap was
also retired in favor of the rope.  With the rope, you can also
back-up anchor the vehicle (a must when doing extrication, self or
assisted, on any type of slope).  With the rope I can, if necessary go
up to about 150' to the nearest anchor (the rope needed for knots and
anchoring being compensated for in the 30' of cable in the
come-along), or I can use multiple anchors if needed.  Necessary to
learn when using ropes are the tensionless anchor, padding *all* rub
points on the ropes (nylon under tension cuts damn easily), the figure
8 knot and all it's variations,  The grapevine knot for joining two
rope ends, 2to1, 3to1 and 4to1 hauling systems for mechanical
advantage, and proper usage of anchor systems. 
Proper anchor points for any extrication on a vehicle is the frame.
Specifically a tensionless anchor on the frame.  Anywhere else is
likely to come off if enough tension is applied (if you apply enough
tension that the frame comes off then yer in trouble well beyond the
scope of this post!).  Pad all sharp bends.  

If the pull is any significant distance, use a blanket or coat placed
in the middle of the rope to help damp any recoil should the line
snap.  If the pull is serious use double anchor points on all
vehicles, and a double line between them.  As has been said before, no
one should be anywhere near the operations, except those actively
involved, and fer yer own sakes stay damned clear of being inline with
the ropes/cables/chains/etc when they are under tension if you can
help it. 
Other *required* equipment for emergency operations.
Plenty of light sources.  These things almost always happen at night.
Flares for hazard indentification.  These can also be used for fire
starting the wettest of wood, and are self-starting.
Entrenching tool.  Not the cheap copies, but the heavy duty,
preferrably the WWII *German* made ones.  Stay away from the ones that
also have the cute little pick on the back.  Sharpen the front of the
blade.
A couple of good blankets.  The local army/navy should have decent
wool ones for $10@.  These can be used to keep you warm, pad anchors,
absorb recoil, and to pad all the metal gear you're keeping behind the
truck seat/whatever.
A cheap towel.  This can also be used for padding, but far more
importantly it can be used to dry your hands when you get back into
the vehicle so you have a good grip on the steering wheel


>Post a note at your local climbing/outdoor shop.  Offer $20 for a 
>retired 11mm climbing rope.  They're 150-165 feet long, designed to
>absorb shock, easy to tie/untie and they're light weight.  Climbers
>have to retire them after about 5 years (safety concerns) so they 
>usually have several laying around collecting dust.  I have one in
>each vehicle, and give them to my friends.


As one other poster noted, as a note to the original poster of this
thread, please don't charge for extricating someone, you'll need it
too one day.
-- 
Anmar Mirza   # Chief of Tranquility  #My Opinions! NotIU's!#Purveyor of
EMT-D         # Base, Lawrence Co. IN # Legalize Explosives!#nontraditional
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