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Maestro 40 Electric sail yacht - First views

First glimpse on the measurement data collected from Pilot Boat 2.0.

Maestro 40 is built to be as light as possible by using sandwich structures to almost everywhere. Weighting something between 6-7 tons it's considerably lighter than it's close rivals. Anyhow the results show that the power / weight ratio is almost the same as in the smaller boats even thought the electric propulsion is not optimized by any means. Now we are using S-drive with Gori 16.5" x 9" folding propeller which will most likely loose 20-30% of the energy.

Next winter the propulsion system will hopefully be modified so that when not in use it can be lifted up from the water. Possible candidates as a motor providers are Torqeedo and Voith. The solutions differ a lot from one to another but more on that later..

Pilot Boat 1.0 for sale

After serving us two seasons we have decided to sell our pilot boat. If you are interested in electric sail yacht in mint condition and lots of goodies feel free to contact us.

Link to advertisement.

Sail Yacht Engine Mk -1

Our local sail loft just delivered a nice christmas present for me. These sails made out of dyneema and pentex fabrics should give us thousands of trouble free sailing miles.

Call me old fashioned but I have serious intentions to sail with my next yacht which is currently being built. What's that supposed to mean you ask? Well it means that the boat will have electric AUXILIARY engine which purpose is only push the boat in and out of harbor; not any further.

So being such an old timer one needs to a) have boat which actually goes somewhere under canvas. b) be able to sail the boat. Damn this is going to be hard!

Luckily on our century we have GRP sandwich hulls and other goodies that Joshua Slocum could only dream about. Modern boats give us such high angles upwind that we are in no position of whining about wrong wind directions or other annoyances usually driving todays skippers to turn the ignition and start the motor sailing.

Torqeedo Cruise 2.0 tested

I had the opportunity to test Torqeedo's most powerful Cruise 2.0 model in our test boat. In the chart are boat's power requirements for the inboard engine with different propellers and comparison to Cruise 2.0 outboard (speed in knots on X-axis). To our measurements Torqeedo used more electricity than our axel driven three bladed fixed propeller in every speed tested. This is most probably due the smaller diameter of the prop and the planetary gear used?

Feeling for the Torqeedo was that it is definitely powerful enough to push 2.5 ton sailboat in harbor even with bit of wind. Acceleration from zero to say 3 knots took few seconds and boat was easy to handle in close quarters. The actual top speed would have been maybe 0.5 knots higher without boat's own 14" three-bladed propeller dragging along.

Positive facts about the motor were the lightness and the easy installation which only took few minutes.

The negative side of the motor was the noise it generated on higher RPM's. Must have been the planetary gears which are most likely made from plastic that are generating the sounds which echo trough the metallic body of the motor. Well it's nothing in comparison to 2-stroke outboards but having been used to almost silent inboard electric propulsion the difference was remarkable.

Dacron, Dyneema, Pentex, Kevlar, Carbon? Woven or laminate?

Trying to choose the engine for the next sail yacht turned out to be a real mess. I'm talking about the sails of course!

It is not only the type of cut to be chosen but also a jungle of different materials and production techniques that are used in modern sail clothes. After numerous meetings with the sail makers and endless browsing of the internet the black magic behind the subject is starting to open.

In the picture there is Dacron, Pentex laminate and woven Dyneema cloths before stress tests made by tearing, biting and wrinkling them :-)

Any help with this matter is gladly accepted! The goal is to find the best option for serious long range cruising.

Helsinki - Tallinna Race

Seven hours of good spanking took us cross the Finnish gulf from Helsinki to Tallinn in the dark but warm autumn night. With wind speeds of 22-27 knots straight from the nose and wave heights exceeding 2 meters the boat was a bit overpowered even with 10 people hanging on the side.

Scoring 16 out of 38 in our class (LYS 1) we were pretty happy with the outcome since we had only four days of practice with the boat before the competition. Training continues tomorrow and we are hoping to kick some ass before the sailing season is ending here North..

In the picture our fearless crew (-me) happily standing in Pirita guest harbor in Saturday morning. After sauna and few beers everybody were pretty much ready to sleep having been up for the whole night in the race.

Busy holidays with Tigru (Flying Tiger 10M)

While trying to learn sailing by competing with keel boats the situation got a bit out of hand. One thing led to another and in the beginning of August we ended up having this new toy (Flying Tiger 10M) standing in a container at Helsinki. Also we had founded a company with my friend Anssi to sell these fast devils and to promote sail racing with modern keelboats in Skandinavia.

Tigru is a typical product of today. Designed in USA, parts all over the world (carbon fiber mast from Australia, sails from Philippines, blocks from USA) and assembled in China. With roughly 100 man hours in Finland the boat was ready to be launched. Sadly we are using a horrible gasoline outboard luckily only to push her out from the marina just enough to get the sails up after the break water.

Propeller makes the difference

Once the boat was up for repairs I managed to change the propeller from 14x9" two bladed flex-o-fold to 14x13" three bladed fixed.

Even thought I knew the folding propellers are poor performers I have to admit that the results were quite surprising. The table above shows how much less energy the fixed propeller needed to push the boat on flat seas.

With these figures the boat has a range over 40 miles with speed of 4 knots. Also the fixed propeller turns much smoother and there was almost no vibration even when running flat out.

Picture of MV10 electric sail boat propulsion

People have been asking for pictures of our motor setup so here is one.

Stuff in the picture from left to right: Normal 12v/75Ah house battery for lights, VHF, heater and stuff (in red box). DC/DC converter for charging the 12 volt system (small black box). Motor controller (big black box). And lastly the motor (black pancake) and reduction gear with thrust bearing (the silver one).

Gear is connected to prop shaft via R&D flexible coupling which also electrically isolates the gear from prop shaft (just to be sure)..

After three months of intensive use the engine compartment is still so clean that one could eat off it.

Electric boat offshore tests

Crossing the Gulf of Finland was the "acid test" for our electric boat. The 45 nautical miles that part Finland from Estonia is mostly open sea with lot of traffic in every direction. The fast passenger crafts roar between Helsinki and Tallinn while the huge cargo ships hail stuff in and out St. Petersburg.

On the starting day I woke up pretty early to check the boat. Knowing the propulsion system pretty well the only matter that I was worried was the attachments of the 80kg battery pack. Fortunately that fear was irrelevant since the pack did not move at all despite the pretty rough waves confronted.

Crossing the gulf to south was an easy task. We had nice 20+ knots of wind from east and trip took only about 7 hours. On the way back the day was almost calm and there was huge swell left from the last days wind. In the evening wind woke up and also brought us nice refreshing rain. Fearless first mate Punin is keeping the helm in the picture above.