A used car salesman trying to sell a car with a worn out motor could tell
people that the lifters rattling meant the engine was just looser and it
will get better fuel milage because of it. All things being equal, a full
displacement hull with clean lines will move through the water easier than
the same hull with apendages, if for no other reason than increased wetted
surface area. It may be minor or even imeasurable, but nonetheless, they
cannot change the laws of physics, it will produce more drag. If they had
just said "hey, here's what we did and why" it would have been better, from
my point of veiw anyway. They build a GREAT boat, why stoop to used car
sales tactics.
My reading of their literature over the years left me with no illusions why
the strakes were there. Then we have Peter's email informing us that they
provide a very small increase in speed.
I am going to continue to harp on what I believe to be important:
seakindliness and efficiency. According to "Idlewild's" experience, they
don't necessarily go together. Example: a buddy of mine had a C&C 36 and I
had a Crealock 37. His boat was faster (had flatter sections and more beam)
and could point higher (rod-rigging and design.) However, on a particularly
rough and windy day, his boat was left in the dust because my boat could
carry more sail in more comfort than his boat.
So which boat are the most seakindly and efficient?
Ron Rogers
1985 Willard 40
----- Original Message -----
From: "bob england" bob_england@hotmail.com
| If they had just said "hey, here's what we did and why" it would have been
better, from
| my point of veiw anyway. They build a GREAT boat, why stoop to used car
| sales tactics.
All
things being equal, a full
displacement hull with clean lines
will move through
the water easier than
the same hull with apendages, if for no other reason
than increased wetted
surface area. It may be minor or even imeasurable,
but nonetheless, they
cannot change the laws of physics, it will produce
more drag.
So, let me get this straight: If I were to take a
refrigerator box shaped barge and put a pointy
nose-cone shaped apendage on the front, it would go
slower. If I were to put a pointy tail appendage on
the back, it would go slower still?
All kidding and hyperbole aside, I understand the
intuitive statement that's being made. But it's
possible the independant tank test results referenced
by PAE ~10 years ago when they introduced maintenance
strakes as part of the Nordhavn 50 design make perfect
sense to someone skilled in the field of hydrodynamics
and/or fluid dynamics.
Peter
www.SeaSkills.com
Or sales
From: Peter Pisciotta peter@seaskills.com
Reply-To: Passagemaking Under Power
Listpassagemaking-under-power@lists.samurai.com
To: Passagemaking Under Power
Listpassagemaking-under-power@lists.samurai.com
Subject: Re: [PUP] Norhaven hull "bumps"
Date: Sun, 26 Mar 2006 20:41:38 -0800 (PST)
All
things being equal, a full
displacement hull with clean lines
will move through
the water easier than
the same hull with apendages, if for no other reason
than increased wetted
surface area. It may be minor or even imeasurable,
but nonetheless, they
cannot change the laws of physics, it will produce
more drag.
So, let me get this straight: If I were to take a
refrigerator box shaped barge and put a pointy
nose-cone shaped apendage on the front, it would go
slower. If I were to put a pointy tail appendage on
the back, it would go slower still?
All kidding and hyperbole aside, I understand the
intuitive statement that's being made. But it's
possible the independant tank test results referenced
by PAE ~10 years ago when they introduced maintenance
strakes as part of the Nordhavn 50 design make perfect
sense to someone skilled in the field of hydrodynamics
and/or fluid dynamics.
Peter
www.SeaSkills.com
Passagemaking-Under-Power Mailing List