"Jeff" wrote in message
...
I've been thinking about this - since I did give the guy a rough time - So
just how much acceleration is a "Panic Stop"? Did the mast have to be
"encased in concrete" as he said?

A Panic Stop is normally a deceleration. Even if the mast was secured on
the boat rather than on the trailer, it shouldn't have shifted if secured
well.
I suspect it was tied to the bow pulpit and the stern pulpit with no
provision
to keep it from sliding forward (or backward) with a line similar to a
spring line.

The braking distance, according to
http://www.ortrucking.org/stopping.htm
from 65 MPH is 245 feet for cars, 454 for trucks, not counting reaction
time. To decelerate at the force of gravity (one "G" or 32 feet per
second squared), the stopping distance would be under 150 feet, so a truck
is nowhere close to that. For a report on actual panic stop decelerations
and other tests using police cars, see:
http://www.nlectc.org/pdffiles/tirerprt.pdf

Since the boat generally has a vertical force equal to one G, and the
force of deceleration is somewhat less than that, then net force in a
panic stop is similar to being at rest at a 30 degree incline, though
stronger, maybe by 20 or 30%. (Even at one G, it would be only 40%
stronger than being at a 45 degree incline.) Clearly, anything not tied
down could slide around, but there is no reason for the mast to move, or
even for the bracket to break.

An other way of looking at this is that when the mast is hoisted, it will
have a force on its axis easily double that of a "panic stop." Would a
slippage of 2 feet be acceptable during that maneuver?

Its pretty clear that the mast slippage was the fault of the preparation,
not a panic stop. The bracket is a little harder to determine - It
shouldn't break from a panic stop, but it could have been from normal
bumps, or previous damage, or both. But again not the fault of the
trucker.




DSK wrote:
sherwindu wrote:

Recently shipped my sailboat from Florida to Racine Wisconsin using
American Boat Transport.
When boat arrived, mast on deck had shifted foward about 2 feet,
although it was secured well
in three places.


Why was the mast "on deck?" It's standard practice... and much better...
to secure the mast to the trailer. And if it shifted, then it obviously
wasn't well secured.


.... Driver says he noticed shift while driving down the highway. More
like he had
to do a panic stop. Everything inside the boat was tossed about.
Hanging nets came down, etc.
Only after the driver left Racine did I notice the outboard bracket was
cracked, and luckily the
engine did not fall off the boat.


What??!?! You left an outboard motor hanging on a transom bracket for a
1000+ miles? You're lucky it didn't go through somebody's windshield.

... American Boat refuses to accept responsibility for this, or pay
for
a new bracket.


And why should they? Sounds to me like the mess is 99.9% your own fault.

... There are many reputable boat transporters. I just picked a bad
one.


Nah, more like the trucking company picked a bad customer...


Sherwin D.


Are you sure your name isn't Crapton Neal?

DSK