Dinghy Mounting
So, why don't I see more dinghies mounted side to side? Am I missing
something?
In my case, it now only was trim, but visibility. I carry my dingy on the
Sundeck roof (43ft Albin Sundeck). When I built the chocks to carry it (10ft
Avon, 25hp 2 stroke) I tried it on a temp basis mounted sideways and it
totaly blocked the rear view. By turning it inline with the big boat, I can
see past it to see those big ships coming up behind me.
Brent Hodges
I'm trying to determine how to mount a dinghy on the boat deck of my boat. I noticed that most boats in my boat's class (15' beam) are mounting their dinghy in line with their boat. With the popular 10'6" (overall length probably closer to 11'6" with the outboard in the up position) you would take up 4+' more boat deck length than you would with the same dinghy mounted side-to-side. In my case, that's 4 feet of boat deck that can be used for personal things. So, why don't I see more dinghies mounted side to side? Am I missing something?
Thanks,
Gil
On 3/9/06 1:36 PM, "trawlergil@comcast.net" trawlergil@comcast.net wrote:
So, why don't I see more dinghies mounted side to side? Am I missing
something?
Trim. A heavy motor can have you listing, as I do with a new 50 HP, super
heavy 4-stroke. Just plan for it (i.e. Place the beer cooler on the opposite
side as the dinghy motor) and thus giving your ladies more sunbathing space!
Bob
Robert Calhoun Smith Jr
M/V MARY KATHRYN
Hatteras 58 LRC
The Jib Room
Marsh Harbour, Abaco
BAHAMAS
Here is a question addressed to the general list.
How many people have a stability calculation done prior to mounting a
dinghy up on the "boat deck"
I realize that some boats are designed to carry a dinghy up top right
from the drawing board.
In fact I seem to recall one listee replying that if they did not have
the dinghy up top the boat has a jerky roll motion that is unpleasant.
However, when a naval architect does design for a dinghy up top he also
indicates the maximum weight of this load at that height.
Newbies may not be aware that adding even relatively small weight high
up will greatly affect the metacentric height and thus the critical
heeling angle of the boat. Excess weight up high will increase the roll
period and also decrease safety.
And then of course there is all that extra "stuff" you invariably store
in the dinghy.
Bigger motor, extra fuel tank, a small anchor, oars, safety equipment
etc. etc.,
The point being we had a vessel capsize right outside the harbor mouth
because the skipper had over loaded the vessel beyond it's safe limit
and when a bigger than normal wave (wake? ) got under the counter it
rolled the boat into a capsize.
Does anyone even know exactly what the maximum allowed weight is for
carrying on their own boat deck and do you know how much your particular
dinghy weighs?
Cheers
Arild
Arild, no doubt a good question. However, in our case, I'm taking about the
weight equivalent of a couple of large people.
I'm sure there's more to it than maximum weight of the boat on the boat
deck. Wouldn't full fuel and water tanks counter, at least to some degree,
the weight on the top? If you're going to actually look at the numbers, how
about the cumulative weight added to the top of the boat? High up on the
radar arch there may be 150 pounds or more for radar, SATCOM systems and
lights.
While we're on it, how about fore and load balancing? On a popular 36' aft
cabin trawler, when the manufacture adds his 8KW ONAN GENSET and bow
thruster the aft section of the boat rides extremely high in the water,
almost to the point of exposing the chine, and is difficult to control in a
following seas condition.
My bet is that this degree of information is hard to come by.
Gil
-----Original Message-----
From: Arild Jensen [mailto:elnav@telus.net]
Sent: Thursday, March 09, 2006 2:35 PM
To: trawlergil@comcast.net; 'T&T T&T'
Subject: RE: Dinghy Mounting
Here is a question addressed to the general list.
How many people have a stability calculation done prior to mounting a
dinghy up on the "boat deck"
I realize that some boats are designed to carry a dinghy up top right
from the drawing board.
In fact I seem to recall one listee replying that if they did not have
the dinghy up top the boat has a jerky roll motion that is unpleasant.
However, when a naval architect does design for a dinghy up top he also
indicates the maximum weight of this load at that height.
Newbies may not be aware that adding even relatively small weight high
up will greatly affect the metacentric height and thus the critical
heeling angle of the boat. Excess weight up high will increase the roll
period and also decrease safety.
And then of course there is all that extra "stuff" you invariably store
in the dinghy.
Bigger motor, extra fuel tank, a small anchor, oars, safety equipment
etc. etc.,
The point being we had a vessel capsize right outside the harbor mouth
because the skipper had over loaded the vessel beyond it's safe limit
and when a bigger than normal wave (wake? ) got under the counter it
rolled the boat into a capsize.
Does anyone even know exactly what the maximum allowed weight is for
carrying on their own boat deck and do you know how much your particular
dinghy weighs?
Cheers
Arild
My logic in putting my 355lb Carolina on substantial stern davits was I
didn't care about marinas, wanted to keep the boat higher than the transom,
but low enough not to impact stability, and, as a bonus, it helped to offset
the 400' of chain in the bow chain. I can also put a few solar panels on the
top of the davits.
Since I'm a big dog, a 6 part block and tackle works fine to raise it, but I
bought a $5 winch at an SSCA GAM with a handle so Gwen can raise the "heavy
end" of the dinghy with mechanical help if I'm incapacitated.
Dipping your rails in the water is only fun in a sailboat. I'm pretty
careful what I put up high...
Regards....
Phil Rosch
Old Harbor Consulting
M/V "Curmudgeon" MT44 TC
Currently lying Bond Creek, NC