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designed by Bernd Kohler

ECO 75 Power Cat

L.o.a. - 7.50 m
Beam - 3.22 m
Weight empty - 800 kg
Weight max. CWL - 1400 kg
Outboard engine - 20-40 hp
Speed - 18-25 knots

The ECO 75 power cat is the big brother of the ECO power cat. Designed along the same lines and with the same philosophy. Easy to build boat by an amateur. Construction is the time proven plywood/glass fiber/Epoxy composite system. Nothing can match this system for weight, costs and easy of construction. Besides this advantages no maintenance will be necessary over many years.

The hulls start with a deep V on the bow and a wide V at the transom. So the boat will be sea worthy. The hulls are designed for medium speed. Speed with a 25 HP engine will be around 25 knots full power and 18 knots at half power. So the boat will be very ECOnomical to run and maintain.

One attractive features is the front cockpit. This is not only a nice place for sun bathing but also a safe place for anchor maneuvers. The front hatch makes it not necessary to walk over the deck in a bad weather situation.

1 Forward cockpit 6 locker 11 berth
2 Anchor 7 pantry 12 settee/double berth
3 bench 8 steering position 13 bath room 
4 entrance to cockpit 9 cockpit lockers 14 hanging locker
5 steps 10 cockpit 15 steps

The inside lay out with the enclosed bath room speaks for it self. In hulls have standing height. The height on the bridge deck saloon is  1,20m. Enough for comfortable seating on the settee. The boat is build from 8 and 6mm plywood over stringers. The construction manual describes an easy way for fairing. In the end this is the quickest way to build the boat. The whole boat is covered with fiber glass and painted with PU paint. 

The plans consists of 20 drawings. The technical drawings are to scale 1 : 1. File format PDF (DXF files available. The 14 pages manual gives a description of the construction of the boat.

Click HERE for sample drawing

ECO 62 Houseboat

To have fun on the water a houseboat is a practical solution. The exist already in all possible shapes. Many more house as boat, others more boat as house. Here a bit an other approach. The ECO 62 is a catamaran houseboat. Compared to houseboats of the same size the boat is light and a bit more boat as house.

L.o.a. - 6.20 m
Beam - 2.5 m
Draft - 0.23 m
Weight - 410 kg
Weight max. CWL - 890 kg
Power - Variable

The empty weight of about 410 kg is not much for a craft of this size with this lot of accommodation. A bonus of the low weight is that the craft can be trailered behind a modest sized car.

The load capacity is higher as its own weight ( empty weight 410 kg load capacity 480 kg). By placing a double berth transverse at the bow much room is gained for the saloon. Good accommodation is paramount in my view on a houseboat. A big open saloon, a good sized cockpit for socializing also. The saloon and the cockpit are at the same level. The standing headroom is over the whole length of the interior 1,94 m (6 feet, 5 inch).

click image to enlarge

The bench can be used as an other double berth at night. A fair sized bathroom is an other asset and nice to have.

The cabin sits on the top of the hulls. So the hulls are basically empty. There is sufficient space for water tanks till 200 liter. Brown water tanks from the toilet and pantry. Batteries for electric drive(s): Of course closed cell batteries have to be used.

If a gas cooker is used the bottle can be placed direct underneath the pantry with ventilation openings at the side of the deck house far above the water line. The hulls have 1400 liter volume for floatation, so the craft can not sink.

Construction is the proven and easy to learn wood/glass/Epoxy composite construction system. The design is on 5 bulkheads and wooden stringers. Easy to learn also for a novice in boat building. As mentioned the craft is light. A hull weights around 50 kg when finished. So turning the finished hulls can be if need be done by one person. Building up the bridge deck is the same. The bridge deck is build up from 12 mm plywood. A 12 mm plywood panel weights typical 18,3 kg. So can be handled by one person to. By the way all other plywood used is 6 and 4 mm plywood. Laminated together where need. Example: Keel to chine is build up from two layers of 6mm plywood.

The hulls slide easy and effortless through the water. So not much power is needed to propel the boat. Powering the boat depends where the boat is used. The boat can be powered for instance with small electric trolling motors. Example: One at the bow two at the transom. The will have 150 pound of trust good for about 8 km per hour. This is the speed limit on
many channels and recreation resorts.

click image to enlarge

Or on each transom an outboard with about 20 HP. This would be good for around 20 knots. A bit fast, all the cutlery will jump in the cabinets.

My favorite drive for this craft is the surface piercing drive, with a 15 HP engine. If you search careful the complete drive will cost about US $ 900,00. In this configuration the boat will give you about 12 knots of speed. The engine is a two cylinder four stroke engine, air cooled. But with a foam lined cover the high wining noise of the fan cooling can be diminished by 80 %. So the engine would be not more noisy as two outboard engines.

Surface piercing drives are also known as mud drives. For maneuvering in a port I would add an electric trolling motor at the bows.

The development of new houseboats is almost standing still. So here some new and a bit unconventional ideas to change that.

Maisons 04/20/2015
B. Kohler


These plans available at Duckworks

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