I arranged a consultation via phone with Jay E. Paris (designer of
the F-33) .
Below are my notes which I’m posting in case the are helpful to
others. I hope they are clear although I may not have fully
understand all of the technical points he made.
Alan Kusinitz F-33 Hull # 51
Regarding off shore cruising, he believes it is a suitable design
and is aware of several that competed in Trans Atlantic Ocean races
and performed quite well. In one race from the Canaries to Barbados
a Freedom 33 clocked 15 days 16 hours. (I also spoke with Eric
Sponberg who was chief engineer at Freedom when these were being
built and he was aware of circumnavigations as well).
He mentioned the following special aspects of the design of the hull
that might not be apparent:
• Diagonals are quite straight
• Hollow at the bow and design of the stern decrease drag, and
at the bow reduce the wave resistance
• It is designed with higher prismatic coefficient to give
lower drag at higher speeds
• The center of gravity is well aft which keeps the rudder
immersed and reduces broaching
• Although there is significant wetted surface area, there is
lower wetted surface girth which provides performance better than
might be apparent from the wetted surface area alone
• The rudder is quite full in its forward section which helps
with stern wave action and has some affect on maximum speed
• Although he was not involved in the design of the fixed keel
models it is clear of course that the righting moment and stability
would be improved by the fixed keels
• Although LPS calculations were not done at the time of the
boat’s design, he believes that the LPS would be very high given the
hull design and the high trunk cabin.
• Having seen pictures of the fixed keel he believes that the
aft end of the keel could be faired and shaped better to reduce
turbulence where a thin part of the aft end of the keel meets up
with the large flat bottom of the center board trunk for the boats
without center boards. He can’t quantify the impact but its clear
some improvement could be made.
• Although he wasn’t involved in the conversion to the fully
battened sails with the sail track, he believes that was a positive
move as to get the maximum performance from the original rig took a
great amount of skill and in addition there is increased sail area
and other benefits from the fully battened rig
Mr. Paris also said he has the line drawings for the Freedom 33 and
if there was enough interest he would be willing to share them for
the purpose of making half models and his fee would be a nominal fee.
I arranged a consultation via phone with Jay E. Paris (designer of
the F-33) .
Below are my notes which I’m posting in case the are helpful to
others. I hope they are clear although I may not have fully
understand all of the technical points he made.
Alan Kusinitz F-33 Hull # 51
Regarding off shore cruising, he believes it is a suitable design
and is aware of several that competed in Trans Atlantic Ocean
races
and performed quite well. In one race from the Canaries to
Barbados
a Freedom 33 clocked 15 days 16 hours. (I also spoke with Eric
Sponberg who was chief engineer at Freedom when these were being
built and he was aware of circumnavigations as well).
He mentioned the following special aspects of the design of the
hull
that might not be apparent:
• Diagonals are quite straight
• Hollow at the bow and design of the stern decrease drag, and
at the bow reduce the wave resistance
• It is designed with higher prismatic coefficient to give
lower drag at higher speeds
• The center of gravity is well aft which keeps the rudder
immersed and reduces broaching
• Although there is significant wetted surface area, there is
lower wetted surface girth which provides performance better than
might be apparent from the wetted surface area alone
• The rudder is quite full in its forward section which helps
with stern wave action and has some affect on maximum speed
• Although he was not involved in the design of the fixed keel
models it is clear of course that the righting moment and
stability
would be improved by the fixed keels
• Although LPS calculations were not done at the time of the
boat’s design, he believes that the LPS would be very high given
the
hull design and the high trunk cabin.
• Having seen pictures of the fixed keel he believes that the
aft end of the keel could be faired and shaped better to reduce
turbulence where a thin part of the aft end of the keel meets up
with the large flat bottom of the center board trunk for the boats
without center boards. He can’t quantify the impact but its clear
some improvement could be made.
• Although he wasn’t involved in the conversion to the fully
battened sails with the sail track, he believes that was a
positive
move as to get the maximum performance from the original rig took
a
great amount of skill and in addition there is increased sail area
and other benefits from the fully battened rig
Mr. Paris also said he has the line drawings for the Freedom 33
and
if there was enough interest he would be willing to share them for
the purpose of making half models and his fee would be a nominal
fee.
I arranged a consultation via phone with Jay E. Paris (designer of
the F-33) .
Below are my notes which I’m posting in case the are helpful to
others. I hope they are clear although I may not have fully
understand all of the technical points he made.
Alan Kusinitz F-33 Hull # 51
Regarding off shore cruising, he believes it is a suitable design
and is aware of several that competed in Trans Atlantic Ocean races
and performed quite well. In one race from the Canaries to
Barbados
a Freedom 33 clocked 15 days 16 hours. (I also spoke with Eric
Sponberg who was chief engineer at Freedom when these were being
built and he was aware of circumnavigations as well).
He mentioned the following special aspects of the design of the
hull
that might not be apparent:
• Diagonals are quite straight
• Hollow at the bow and design of the stern decrease drag, and
at the bow reduce the wave resistance
• It is designed with higher prismatic coefficient to give
lower drag at higher speeds
• The center of gravity is well aft which keeps the rudder
immersed and reduces broaching
• Although there is significant wetted surface area, there is
lower wetted surface girth which provides performance better than
might be apparent from the wetted surface area alone
• The rudder is quite full in its forward section which helps
with stern wave action and has some affect on maximum speed
• Although he was not involved in the design of the fixed keel
models it is clear of course that the righting moment and stability
would be improved by the fixed keels
• Although LPS calculations were not done at the time of the
boat’s design, he believes that the LPS would be very high given
the
hull design and the high trunk cabin.
• Having seen pictures of the fixed keel he believes that the
aft end of the keel could be faired and shaped better to reduce
turbulence where a thin part of the aft end of the keel meets up
with the large flat bottom of the center board trunk for the boats
without center boards. He can’t quantify the impact but its clear
some improvement could be made.
• Although he wasn’t involved in the conversion to the fully
battened sails with the sail track, he believes that was a positive
move as to get the maximum performance from the original rig took a
great amount of skill and in addition there is increased sail area
and other benefits from the fully battened rig
Mr. Paris also said he has the line drawings for the Freedom 33 and
if there was enough interest he would be willing to share them for
the purpose of making half models and his fee would be a nominal
fee.