Been out four times now things are starting to come together nicely
See
http://youtu.be/eW078PPgJak
And
http://youtu.be/1OH-ZYPNFu4
Monday, 2 September 2013
Saturday, 25 May 2013
Fantastic day, TP03 transported up to the club and assembled for the first time. Went realy well only two issues. Had to move one fitting on the mast and the seating platform is very slippy, should get him on the water in a couple of weeks.
See http://youtu.be/BtOH5Ga6rvM for all the details.
See http://youtu.be/BtOH5Ga6rvM for all the details.
Sunday, 19 May 2013
I have now built a simple model of my lug rig with adjustable CE, I am very impressed with this rig I think it may well have some real potential. It offers a very clean sail, low CE and steering. Only suitable for small proas like my minimal proa though.
For discussion see http://proafile.com/forums/viewthread/244/
for some video see http://www.youtube.com/watch?v=JyE0FsI_GAQ
For discussion see http://proafile.com/forums/viewthread/244/
for some video see http://www.youtube.com/watch?v=JyE0FsI_GAQ
Saturday, 18 May 2013
The minimal proa continues to be my favourite new design, just the bare bones of a proa offering quick simple sailing hopefully along the lines of an international canoe but much easier to sail.
For discussion see http://proafile.com/forums/viewthread/239/
For discussion see http://proafile.com/forums/viewthread/239/
While working on the minimal proa proa I briefly got diverted to the idea of a inflatable version but after working out the details it just became complex without any great advantage.
For discussion see http://proafile.com/forums/viewthread/239/
For discussion see http://proafile.com/forums/viewthread/239/
This is the Strangford Lough Cruiser, it is a combination of a Bank’s Dory, Caddo Lake Bateau and off course a proa.
The brief is for a singlehander or two up for a day sail or a single hander for ultralight camping. The overall length is 14ft, due to building limitations. That’s where the Dory mid ships section comes in. With a 260kg displacement the hull draft is 120mm and L:B 11:1 up the displacement to 360kg and draft 200mm, L:B 10:1. I would have liked a finer hull but the draft increased too much, the bows are sharp giving fine entry. The Bateau influence is twisting the sides of the flat bottom v mid section into vertical stem maximising length and L:B. This twist creates some good flair for reserve buoyancy and keeping the crew dry.
Back to the Dory mid ships section, the flat of the bottom is 200mm, the gunwale 500mm above and a beam of 800mm. This gives space inside for a temporary birth of ‘bivi’ camping, a simple ‘tent’ protecting against the elements.
The beams in the picture are 1600mm apart so some ‘accommodation’ would be under the beams and deck. The ‘birth’ is removable like a camp bed made of material under tension
For discussion with like minded proa people see http://proafile.com/forums/viewthread/259/#1954
The brief is for a singlehander or two up for a day sail or a single hander for ultralight camping. The overall length is 14ft, due to building limitations. That’s where the Dory mid ships section comes in. With a 260kg displacement the hull draft is 120mm and L:B 11:1 up the displacement to 360kg and draft 200mm, L:B 10:1. I would have liked a finer hull but the draft increased too much, the bows are sharp giving fine entry. The Bateau influence is twisting the sides of the flat bottom v mid section into vertical stem maximising length and L:B. This twist creates some good flair for reserve buoyancy and keeping the crew dry.
Back to the Dory mid ships section, the flat of the bottom is 200mm, the gunwale 500mm above and a beam of 800mm. This gives space inside for a temporary birth of ‘bivi’ camping, a simple ‘tent’ protecting against the elements.
The beams in the picture are 1600mm apart so some ‘accommodation’ would be under the beams and deck. The ‘birth’ is removable like a camp bed made of material under tension
For discussion with like minded proa people see http://proafile.com/forums/viewthread/259/#1954
Friday, 15 March 2013
Friday, 8 March 2013
Cutting a long story short as the family skied in the glorious Courchevel I sat for nearly a week nursing a broken collar bone. While they had fun I did the usual, pondered Proas. The above is a cruising proa and the earlier one is a minimal proa. The real upset is that last weekend I should have been launching the proa TP03 which was all ready to go but now delayed until the shoulder fixes.
Thursday, 7 March 2013
Minimal
Proa
I have been working on my minimal proa while my
shoulder heals which delayed the launch of TP03
Description,
specification
Minimal
Proa with balanced lug rig and moving leeboard to align CE with CLR. Single
central AKA, nod to Skip Johnson's AC/DC and Bionic Broomstick.
This is a
concept for a possible next build after testing my current proa TP03 and will
help clarify tests and developments to be done with TP03. The other concept I
am interested in is a slightly bigger design with more freeboard and a small
central open concept. This will allow two crew and storage of camping gear. All
other aspects and hence development tests for this concept as per here.
Main hull
•
LOA 12ft
hull, (3.7m) beam and draft 240mm, depth of hull 360mm, freeboard 120mm
•
L/B 15.25
•
Target
weight whole craft 50kg, tough target, but research and a few calculation have
given me confidence
•
Main hull
displacement 150 kg total hull buoyancy 250kg, little reserve but think
about Hobie 16, trimaran floats, swath,
Tepuke etc
•
Deck
section at bows, addition of foam and glass to create wave piercing bow. This
should counter low freeboard and crew fixed in the middle
Outrigger AMA
•
Outrigger
buoyancy 50kg allows for crew at 50% beam
•
LOA 2.6m
(8.5ft) beam 160mm
•
L/B 16.25
Overall beam tbc approx 1.5 to 1.8m
Construction,
•
ply, simple
box
•
plywood and
polyurethane foam bulkheads.
•
All hull
panels 3mm Okoume
AKA
•
3mm egg box
constructed 'box' based on International Canoe sliding seat.
•
Hydrodynamic
box shape lifts AKA 250mm above deck, as a result underside of AKA 370mm above static waterline. This reinforced
box also contains a deep 'bury' for the mast and links righting forces with
heeling forces without loading the hull. Leeboard loads are relatively close.
The only other load being the buoyancy which is obviously spread throughout the
hull. This all helps to produce a light structure.
AKA to AMA connection
•
Two
flexible beams allow movement of AMA relative to main hull
Rig
•
balanced
lug,
•
unstayed
mast,
•
area 8m sq
Steering and lateral resistance,
•
leeboard
mounted on track moves fore and aft to steer by achieving CE / CLR balance
Why's and downsides
•
Proa
(Pacific)
•
Max
performance for given materials, performance means many different things, in
this case it is reasonable speed in a minimal package
•
Downside,
control issues, additional complexity?
•
Minimal
•
Low
freeboard, very light weight,
•
Less
materials
•
Cost
•
Weight
•
Less
room to build
•
Easy
to transport, fastest way to get upwind is behind / on / in a car
•
Easy
to handle on land
•
Downside
low freeboard drag,
•
Downside
low buoyancy limits use; single handed daysail
•
Lug
rig
•
Good
performance for simple set up and small spars
•
Lower
hull stress
•
Less
set up time
•
Low
CE
•
Heeling
•
Pitching
•
Downside
ultimate performance
•
Free
standing mast
•
Lower
stress
•
Stress
all in one place
•
Less
set up time
•
One
central AKA, also the seat
•
Simple
•
Stress
in one place as above
•
Away
from bow so possibly less drag from wave action
•
Less
set up time
•
One
item two uses
•
Downside
can't trim fore and aft
•
Downside
limits to one user
•
Steering
with moving leeboard
•
One
foil only
•
Low
drag
•
Downside
unproven, test with 2b
•
Sharpie
(box construction)
•
Very
simple build
•
Flat
plate, ply, construction
•
Max
buoyancy for box size
•
Helps
leeboard system
•
Bow
sections promote lift
•
Latest
AC, A Class appear to have flatter sections
•
Downside
higher weight and wetted area for buoyancy
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