Re: [PCW] Nose-diving
Never heard of a powercat nose-diving. We worried a bit we were surfing
down 8 -10 seas in our PDQ 34 last fall, but it always came back up. A lot more
buoyant than a Hobbie Cat!
Henry Clews
aboard "Sno' Dog" in Vaxholm, Sweden (with 6 other PDQ's)
see website, Baltic Adventure Page 5
(http://www.geocities.com/snodoglog/07BalticAdventure-Pg5.html) for latest photos - sure is pretty here! (Will try
to post most soon).
In a message dated 7/11/2007 12:02:13 P.M. Eastern Daylight Time,
gramario@tin.it writes:
Very interesting. I should like more info. on the new Highland 35. Perhaps
I'll see if a visit to La Rochelle can be organised.
On another note, has the list archived any discussions re. the stability of
power cats. We all now that sailing cats can nosedive if they take waves too
fast. What about power cats?
Best,
Rup.
************************************** Get a sneak peak of the all-new AOL at
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The major difference between a sailing catamaran and a power catamaran is the
presence of a rig on the sailing vessel. The centre of effort of the rig will
be quite a long way above the deck and the centre of lateral plane will be
below the surface of the water. This difference in position produces a large
turning moment. In some conditions this is trying to capsize the boat. In
others it is trying to drive the leeward bow down. So remove the rig and
essentially both of those conditions disappear. Without the rig the forces
trying to capsize the power cat or drive its bows under are considerably less
than those operating on a sailing cat. However it continually surprises me
that so many people expect the sailing cat and the power cat to behave the
same. How many times have I heard the "catamarans capsize" comment applied to
power catamarans in the last 30 years!
Regards,
Malcolm Tennant. ARINA MA
MALCOLM TENNANT MULTIHULL DESIGN LTD
PO Box 60513, Titirangi.
Waitakere 0642
NEW ZEALAND
Ph: +64 9 817 1988
e-mail: malcolm@tennantdesign.co.nz
www.tennantdesign.co.nz
www.catdesigners.com
Thank you very much for this information. I did not actually want to imply
that power cats and sailing behaved the same. Rather I was interested to
learn how well power cats behave in rough seas and if any testing has been
carried out, or whether people have had experiences re. these areas. It is
pretty logical I suppose as you only have one life, and it is best to learn
the risks before venturing into dangerous situations. Having said that, it
is of course wise not to venture into rough seas unless absolutely
necessary, but if you do find yourself in them, ....
Regards,
Rup.
----- Original Message -----
From: "Malcolm Tennant" malcolm@tennantdesign.co.nz
To: "Power Catamaran List" power-catamaran@lists.samurai.com
Sent: Wednesday, July 11, 2007 4:14 PM
Subject: Re: [PCW] Nose-diving
The major difference between a sailing catamaran and a power catamaran is
the
presence of a rig on the sailing vessel. The centre of effort of the rig
will
be quite a long way above the deck and the centre of lateral plane will be
below the surface of the water. This difference in position produces a
large
turning moment. In some conditions this is trying to capsize the boat. In
others it is trying to drive the leeward bow down. So remove the rig and
essentially both of those conditions disappear. Without the rig the forces
trying to capsize the power cat or drive its bows under are considerably
less
than those operating on a sailing cat. However it continually surprises me
that so many people expect the sailing cat and the power cat to behave the
same. How many times have I heard the "catamarans capsize" comment applied
to
power catamarans in the last 30 years!
Regards,
Malcolm Tennant. ARINA MA
MALCOLM TENNANT MULTIHULL DESIGN LTD
PO Box 60513, Titirangi.
Waitakere 0642
NEW ZEALAND
Ph: +64 9 817 1988
e-mail: malcolm@tennantdesign.co.nz
www.tennantdesign.co.nz
www.catdesigners.com
Power-Catamaran Mailing List
I can't believe that there has been no resopnse to my inquiry about the
wave-piercer at the AC finals. This boat's spray-free seakindlyness was
startling. As all the other boats around were pounding and spraying, only
she maintained her composure.
Maybe Mr. Tennant could make a call in Auckland to someone who followed the
NZ team and is informed about such things.
Regards, Bert Harrott
----- Original Message -----
From: "Malcolm Tennant" malcolm@tennantdesign.co.nz
To: "Power Catamaran List" power-catamaran@lists.samurai.com
Sent: Wednesday, July 11, 2007 1:14 PM
Subject: Re: [PCW] Nose-diving
The major difference between a sailing catamaran and a power catamaran is
the
presence of a rig on the sailing vessel. The centre of effort of the rig
will
be quite a long way above the deck and the centre of lateral plane will be
below the surface of the water. This difference in position produces a
large
turning moment. In some conditions this is trying to capsize the boat. In
others it is trying to drive the leeward bow down. So remove the rig and
essentially both of those conditions disappear. Without the rig the forces
trying to capsize the power cat or drive its bows under are considerably
less
than those operating on a sailing cat. However it continually surprises me
that so many people expect the sailing cat and the power cat to behave the
same. How many times have I heard the "catamarans capsize" comment applied
to
power catamarans in the last 30 years!
Regards,
Malcolm Tennant. ARINA MA
MALCOLM TENNANT MULTIHULL DESIGN LTD
PO Box 60513, Titirangi.
Waitakere 0642
NEW ZEALAND
Ph: +64 9 817 1988
e-mail: malcolm@tennantdesign.co.nz
www.tennantdesign.co.nz
www.catdesigners.com
Power-Catamaran Mailing List
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4:09 PM
I can't believe that there has been no resopnse to my inquiry about the
wave-piercer at the AC finals. This boat's spray-free seakindlyness was
startling. As all the other boats around were pounding and spraying, only
she maintained her composure.
Maybe Mr. Tennant could make a call in Auckland to someone who followed the
NZ team and is informed about such things.
Regards, Bert Harrott