Interesting dreams ya'll are having about diesel
Dakotas. As I'm the guy who originally wrote about
yanking the 18-wheeler, I've been giving this whole
thing quite a bit of thought.
When I yanked the truck, I was pretty much at the
limit of available traction. We were on a smooth,
level, graded gravel-and-dirt road. My truck dug four
nearly identical holes about two inches deep but still
delivered some forward motion. I braked so as not to
dig in any deeper and then need to climb out of those
holes to continue pulling. So a bigger engine, without
a better driveline and much bigger tires, would not
have added anything to the equation.
My understanding of kinetic recovery or snatching is
largely from a British book titled "Off-Roader
Driving" by Tom Sheppard. He devotes an entire chapter
to it, with significant warnings and disclaimers about
the dangers of doing it wrong.
The key to effective snatch recovery is available
traction and the weight of the pulling vehicle. In an
effective kinetic recovery, you transfer some of the
energy, the momentum, from the tug to the stuck
vehicle, via the stretch of the tow strap. So the
weight of the tug becomes very important. A light
vehicle doesn't snatch very well. My pickup weighs
nearly 5,000 pounds so that probably worked in my
favor.
Suprisingly, the weight of the stuck vehicle is
largely irrelevant. According to Mr. Sheppard, you'll
either be able to move the vehicle or not. If it is
stuck fast, either the tug will cease to move forward
or something will separate. The thing that usually
fails is one of the attachment points. In his book he
shows a Range Rover with broken front and rear
windows. A failed attachment point sent a tow hook
flying completely through the vehicle. So the critical
thing is very solid attachment points, and a backup
restraining system in case one of them fails.
When I pulled the big truck, I did not have any backup
restraining system. I was very concerned about
something coming loose and flying lengthwise through
my truck or the tractor cab. So I purposely was very
conservative with my speed and the length I allowed
the strap to stretch. Luckily, it worked. With a
better pulling system, I could have been more
aggressive and perhaps pulled the truck out with fewer
tries. In any case, it worked.
Just a few thoughts.
-J.
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