Category: Building Blog

The side panels of the main hull are glued on now. Eventually, it looks like a boat!

Its almost winter time in Germany 🙁 In the northern part that means rain, fog, darkness and temperatures around 5°C. No ideal conditions for boat building.

Fortunately, our workshop is equipped with an oven and plenty of firewood. With a good fire it’s quite cozy in there and work is a pleasure!

After 2 weeks, the bulkheads are prepared and in place. Now we work on getting the plywood sheets around them to create a hull.

The cross beams are key components of every multihull. Proasis’s beams are made from plywood and timber in a hollow construction. The outside is reinforced with glassfiber. Each beam is 4.5 m long and weights about 25 kg.

Doesn’t look like a boat yet but we aim to finish the bigger hull of our proa by end of October.

If you like to take a look by yourself feel free to visit us in our workshop:

Its located 15 km from Kiel. The easiest way to get there is to catch a train to Flintbek (regular trains between Hamburg and Kiel stop there). If you take a car leave the A 215 at Blumenthal.

You will find us there every afternoon for the next couple of weeks. Don’t be shy, we are happy about all guests and visitors!

Thanks to some friends we’ve got access to a very nice workshop close to Kiel!

Work on Proasis will start there later this month. If you want to learn how a boat is built feel free to visit us and join the construction team! Everyone is very welcome to become a part of the Proasis team!

Maybe an odd way to start building a boat, but the very first part of proasis will be the rig (naval term for mast, sail and all other parts belonging to them). Why? That’s a bit of a story:

Originally, proasis was supposed to get a free standing carbon mast (free standing means no shrouds to hold it up) with a soft wing sail on it (see a video of something similar here).

Aside of the not very sustainable carbon part we never got happy with the design:

• Much additional work for the mast construction
• High expenses for the materials
• Even more work for sewing the sail (it needs sewed in shape!)
• High bending moments in the leeward hull around the mast bearing
• Unsustainable design, many new and non degradable parts involved

We thought about many workarounds and fancy designs but eventually came back to the (Marshallese) oceanic lateen sail!

Proofed for centuries on the pacific, the biggest ocean of our planet. For us the best sail possible:

• Decent performance (we measured the performance of marshallese canoes!)
• Simple and cheap to build (spars and flat cloth only)
• Low center of effort
• Low stress in the sailcloth

For the spars we were lucky to get tons of old windsurfing mast for free by our sailing club:

The windsurf mast were simply transferred into mast and booms and laid out to test the geometry for shunting:

Next week we will get some cloth and sew the sail. Stay tuned!

Now, after the 1:5 model proa proofed our general concept by amazing sail performance it’s time for something in real size!

To get an impression of what the living conditions on proasis will be we made a full size mockup of the accommodation compartment in the windward hull. In manufacturing and design, a mockup is a scale or full-size model of a design or device, used for teaching, demonstration, design evaluation, promotion, and other purposes. It is probably best known from the automotive industry for show cars, but is an important part of yacht design too.

Our mockup taught us a lot about usability, ergonomics and structural design of the cabin.

As you can see, its a quick and dirty construction from scrap wood and paper boxes. All of that was recycled by us and therefor for free!