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KD 860 - Study Plans

LOA:
28' 2-1/2" / 8.6m
SKU:
BK-KD860-ID-SP
Availability:
Download after check out
$15.00

Description

These are study plans - for full plans, click HERE

This is our smallest offshore cruiser. A sea worthy fast cruiser catamaran for a family of four. The performance of this boat is exceptional on all courses to the wind. To make sure of this, the boat is light and has a low streamlined profile for windward performance. The study plans include diagrams for speed prediction and dynamic stability, so you can see for yourself.

The hulls have the proven trapezoid cross section. For wind ward performance the boat has anti-vortex panels. These work a lot better as low aspect ratio keels and are not as prone to damage as boards. Besides, why spoil one of the best advantages of a multi hull, low draft, to enter coves etc a keel boat never can enter? For an explanation how these work go to the anti vortex article. The boat is, like all our boats, a plywood/glass/epoxy composite construction. Any handy amateur can build this boat without difficulties and surprises.

Construction time around 1200 hours.

Designing a catamaran in this size is a challenge if you would not end up with a floating caravan.

I used our practical experience with our Pelican to design this boat.

The maximum height in the central cabin is 1.48 m. I found the solution for a reasonable ergonomy by using 3 entrances. To step in the hulls, the port or star board entrance is used. The central entrance is very convenient to step in the central seating area. As shown in the drawing, there is amble seat height in the central cabin. There is standing height ( 1,95m ) in the hulls.

The trapezoid shaped hulls have a fine entrance. The length to beam ratio of the hulls is 1 : 11. This will guarantee a fast boat (see spec. for speed prediction). The boat is relative low with good aerodynamic properties. Even with shortened sails the boat will go to windward. A factor often forgotten. There is sufficient room for four persons for extended voyages.

CONSTRUCTION

The boat is designed in a way that even first time boat builders can build the boat without difficulties. All 32 CAD drawings are to scale (1 : 1). A 32 page description will aid you building the boat. All our 26 years of experience designing boats for amateurs is flowing into this design. We chose again plywood as basic material for availability world wide and cost efficiency.

Legend

1 floor
2 bridge deck stringer
3 door
4 chard table /navigation
5 book/instruments shelf's
6 deck stringers
7 hatch 450x380 mm
8 vertical mast bulkhead 12 mm plywood
9 lockers
10 two persons bunk
11 pantry
12 U settee for up to 6

STUDY PLAN

The study plan consists of 16 pages and includes 10 pictures, a short construction description table of contents of the plans and the list of materials - go to top of page.

VIDEO

 

Specifications
LOA/LWL - 8.60m
Beam - 5.60m
Draft hull/rudder - 0.4/0.7m
Weight empty - 1800kg
Weight cwl - 3000kg
Sail area: -  
Main - 27m2
Jib - 10m2
Reacher - 26m2
L/B ratio - 1:2
L/B ratio - hulls - 1:11
Prismatic coefficient - 0.569
Righting moment max - 5600kgm
Optimum speed - 21.5kn
Outboard engines - 2x 6 HP
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Additional Information

Measurement:
Metric
Designer Name:
Bernd Kohler
Sail area (Imperial / Metric):
400 sq. ft / 37 sq. m
Rig Type:
Sloop
Ballast Weight:
n0ne
Keel Type:
Rudder:
Kick-up
Length (range):
24' - 35'11" / 7.32m - 10.95m
LOA:
28' 2-1/2" / 8.6m
Length at Waterline:
28' 2-1/2" / 8.6m
Beam:
18' 4-1/2" / 5.6m
Hull Weight:
Over 1000 lb / 453.59kg
Estimated Hull Weight:
3,968lbs / 1800kg
Draft:
12" - 35" / 30.48 - 91.23cm
Unloaded Draft:
2' 3-1/2" / 70cm
Weight Capacity:
2645lbs / 1200KG
Primary Material:
Marine Plywood
Method of Construction:
Stitch and Glue
Hull:
Multihull
Hull Type:
Planing
Hull Shape:
Flat bottom
Cabin:
Cabin
Power Source:
Internal Combustion
Motor:
Outboard
Horsepower Rating:
2 x 6hp
Built-in Floatation:
Yes
Trailerable:
No
Cartop:
No
Unit of Measure:
Metric
Instruction Manual:
Step-by-Step Instructions
Lofting Required:
No
Recommended Experience Level:
Intermediate
Designer's Thoughts on Experience Level:
Chuck Leinweber's suggestion
Boat Type:
Sailboat
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