[Rhodes22-list] Trailer Sweet Spot

[Jay Curry]

One last post on positioning the boat on the trailer. I did not make it
clear what my situation was or why I was investigating this. I bought a
recycled 20 year old boat. The intended use is to travel with it on trips of
hundreds and occasionally thousands of miles now that we are retired. One of
our favorite places for example is the apostle islands on the southwest
shore of lake superior. It is one of the best places in the country for
sailing and we spent nearly every summer weekend on our boats in those
islands for several years meeting people from all over the world. Other
interests include lake Chelan and Coeur d'Alene. We bought a dual axle
trailer for safety, better tracking, better shock absorption and over all
less stress on the trailer and boat on long distance trips.

Anyway, after 3500 miles transporting a boat I had never seen before on a
trailer I had never used, I learned a few things. First on the list was how
much I hate concrete free-ways. In many ways they are worse than bad bridge
transitions. In both cases, I had to watch my substantial investment bounce
around on the trailer like a swimmer doing the butterfly. The trouble with
concrete free-ways was that this bouncing went on forever and when the
bouncing resonated with the frequency of the bumps, things really got
exciting. With help from the list, I have discovered that some bounce is a
good thing and resisting the temptation to tie the boat down securely was
the right thing to do. And that, also, is the dilemma.

During our trip home, the boat shifted forward or backward in the bunk on
rough inclined roads. The bow bounced severely until we tied it down
vertically with rubber straps that allowed it to react to shocks, but kept
it under control. If you tie the boat down so hard in cannot move up, down,
forward or backward, you force road shocks, some severe, to be completely
absorbed by the hull and subject the boat surfaces to the wear from straps
and other tie-down attachments. On short trips over known routes, all these
concerns go away. On long trips over every imaginable road condition, they
determine, for me at least, if the boat will survive the trip. It makes it a
pretty important concern.

When we arrived home, it was clear the boat had shifted to a poor position
on the trailer that deformed the hull under the forward bunk posts. I began
looking for solutions by joining the list. The first concern, and hardest to
get an answer on, even from Stan, was finding the sweet spot for the boat on
the 66 by 188 inch bunk. Questions about what other support to use or not
use for the bow or keel were pretty easy to work out thanks to the list. You
may recall my first post asked for a reference on the deck under which the
forward bunk post should be positioned. I think I found that sweet-spot
point on my trailer. It is to position the forward bunk post no further
forward than directly below the forward inboard shroud connection on the
deck and no further rearward than the front of the forward most side port. A
few inches backward and the bow ring falls below the bow stop. A few inches
forward and the bunk board end will deform the hull. The boat now rests
comfortably on the bunk with no hull deformation.

The trick now is how to keep it there during transport and still allow the
boat to move in reaction to road shock.  In my mind, it is not
re-engineering or a reaction to something that is considered broken. It is
an essential enhancement to keep the boat undamaged during frequent and long
distant transportation.  I know severe damage will occur if I do nothing and
still travel as planned with the boat. Today for example, I set out to
install a more substantial winch strap since it is the only thing, beyond
the loose safety chain holding the boat on the trailer. It seemed to me that
the existing strap with a 600 pound working weight was a little light.  I
found the through bolt holding the strap was stressed to nearly breaking and
must be replaced. This would never have occurred on short trips. If I can
solve the forward/backward movement of the boat on the bunk and manage the
bow bounce, I am confident the boat will out last me. If not, I suspect it
will not last more than a couple of years before I have to get major repairs
done.

I will keep you posted on what I learn. For now, I have no more questions
for the list on the matter. I am still interested though in the experience
of others on long trips. My next set of questions may revolve around how to
prevent ripping my transom apart with the 3000 pound capacity truck winch
that was installed to lift my 58 pound engine. If I don't stop the winch on
time or the remote gets accidently pressed at the wrong time, I could be in
real trouble. I am considering an adjustable kill switch that is tripped by
the rising engine mount. Take care everyone and thanks.