This came up from a chap yesterday, see in blue below.
My response was that I think 500 liters of water will be fine?
It’s a nice boat for what it is – my only concern may be its
lack of weight carrying ability – its astonishingly light at 2.8T
(lightweight), can’t exactly add 500 l of water and fuel!! Mind you with a
watermaker and some jerry cans it could probably get about a bit….
It’s a uniquely good design for a small cat!
Ricks Proteus 106 in Thailand, note he added to the transom and placed the rudders under the boat.
Read what the designer says about his boat.
See attached notes explaining
everything. The boat built in Thailand was built very heavy, and the
owner added a lot of stuff without ill effect, and it does not seems to have
affected the load carrying capabilities . I am not recommending you build
heavier though!
Kind regards,
Angelo
10.6
METER MULTICHINE PLYWOOD/GRP
SAILING CATAMARAN
This project
has been “gestating” on a personal level
for the last 10 years. My aim is
the smallest family ocean cruising cat,
that is to say with sufficient load carrying capacity to do an ocean crossing
with a family, of minimum cost, and capable of amateur construction with the
minimum of labour and skill. She is also aimed at being a fast, practical &
enjoyable boat for local use. She is small enough for easy shorthanded
use. The hull structure is “pre cut” by
a CNC cutter as a kitset, or can be cut to plotted templates as a cheaper
option if preferred. The Kitset is available from
CKD Boats in Cape Town. Their quality is A1 and different ply type
options are available. Since wastage is minimised ( much less than hand
cutting), and CKD buy much more cheaply than private buyers, one generally
finds that the kit costs hardly more than buying the raw material, and then you
save hundreds of hours in labour. The boat is set up on ply bulkheads and
stringers and the skin is glass taped with epoxy resin along the chines, inside
and out, there are no chine logs. The hull & deck is mostly 9mm ply with
12mm in the forward wingdeck and hull bottom forward. The outside is GRP/epoxy
sheathed. She is simple, strong, fast, comfortable, cheap and “unsinkable”.
The interior consists of four berths (two doubles +
2 singles), a saloon settee, a practical galley with icebox, and a toilet
compartment, all with standing headroom
(1820 under deckstringers) . She is totally functional, and all that is needed
for comfort at sea. She is configured with two machinery and keel
variations: A 4 stroke 20HP outboard on
a hinging nacelle is fitted for economy, as is tiller steering, with “kick up”
rudders. If the motor starts to make trouble it is easily replaced. I haven’t worked out how many times you can
relace it to equal the cost of diesels. Other “choices” in the “gilded lily”
approach stretch to installed water tank versus fitted 20 lit container
storage. However with the outboard and daggerboard combination, and simplest
accommodation gear, we have the fastest boat AND the shallowest draught for the
smallest outlay. People lose sight of the fact that comfort at sea revolves
round some very simple “basics”, a dry bunk with good ventilation, a place to
prepare hot food, a place to sit out of the sun & elements, a private
toilet, standing headroom. The rest is “bells & whistles” which all come at
a price of increased cost, maintanance, and degrading performance.
The rig is the simplest possible, with a pair of cap
shrouds and headstay triangulated, single diamond. The sail inventory is essentially a mainsail,
a roller furler jib, and a storm jib. Optional:
Genneker.
A first class builder estimates
1600 hours, professional hours in a set up boatshop, to unfaired and unpainted
hull, deck, joinery stage. CNC cut kits
from CKD Boats in Cape Town, a very experienced company, is available at a
really competitive price. Email Roy Mc Bride (roy@comlumber.com ) . Most likely
you will find the cost of the CNC kit ( including shipping) is less than a
private person is likely to buy the raw
materials, so that the huge labour saving is more or less “free”!
Wing deck clearance
to DWL (@ displ 3800 kg) is 680mm amidships and 1100mm under the cockpit. The
windeck does not extend forward which is most important. Top speed broad
reaching in flat water and high wind can be around 18 knots (depending more on
one's nerve than anything.) and can average 8 knots on an olympic triangle,
powered up in 16-18 knots breeze.
Payload of crew, fuel, water, provisions in addition to the vessel
complete (with sailing and safety gear, normal loose outfit and sails) is
nominally about 900 kg. This figure could be increased by another 400 or so kg
at the beginning of a long voyage if the boat
consciously not "overpressed" when so loaded. The length/beam
ratio at datum floatation is 9.07. This offers a good compromise between
reasonably slim hulls and good load carrying ability. This is augmented by the
additional "flare" developed in the topsides, whereby beam (and
waterplane area) increases considerably with increasing immersion.
The daggerboard version is more efficient in terms of L/D on the foils.
In addition the drag of the daggerboards retracted is zero, whereas the mini
keels (both!) continue to offer resistance.
The prod and spars are intended to be aluminium extrusions, whose
inertias are specified.
The design license
costs $4500 New Zealand Dollars per
boat to build. Drawings are supplied in PDF format. The templates consist of all frames with shell
deduction, stringer cutouts, access cutouts etc shown for hull, deck and
superstructure, bow and stern profile, daggerboard, (or alternative keel), kick
up rudder. The design consists of: 18
drawings: Lines, hydrostatics, full
scale templates (+ 12 x A0 sheets), general construction drawing, CNC parts
assembly drawings, CNC parts nesting
drawings, arrangement plan and sections, deck arrangement, sail & rigging
plan, dagger board & case construction, rudder construction, chain plate
details, sundry joint details, doghouse & hatch details, outboard motor
hinging nacelle detail, alternative keel detail. Study plans consist of
arrangement drawing, deck arrangement, sail & rigging plan. Note: study
plans have all section information
omitted (other than one "typical" section.) The design has been developed to minimise
labour hours and high skill requirements and high costs. The only
"exotics" involve the external skins of the ply rudders and
daggerboards, which are carbon, since the excessive amounts of GRP needed would
make control of the shape and avoiding excess weight problematical.
LENGTH OVERALL 10.600 Meters
BEAM
6.360 Meters
DRAUGHT 0.370/1.75 Meters
(dagger up/down)
DISPLACEMENT 2600/3200 Kilogr
(light conditon, lght/hvy inst)
MAINSAIL 48 Sq Meters
ROLLER FURL JIB 24 Sq Meters
GENNEKER
58 Sq Meters
FRESH WATER 140 liters (installed or 20 lit containers)
CONTACT:
Lavranos Marine Design
Pricing on request
