Sailing Magazine
The first vessel to be self-sufficient in energy, “Energy Observer”, recently completed her first trans-Atlantic passage with high praise given to her newly fitted Bruntons Autoprop Eco*Star propellers. The propellers replaced the vessels original four blade fixed pitch propellers and have been partly responsible for a significant improvement in her performance since a refit was carried out last winter.
Energy Observer has also been fitted with two Oceanwings to further enhance her energy saving abilities; a change which turned her overnight from a purely power driven vessel to a kind of motor sailor, even though the surface of each automatic wing is only 30m2. It was also obvious to the team running the project that fitting propellers more suited to a motor sailing vessel would offer considerable further improvements, increasing the vessels speed by reducing propeller drag when sailing and optimising hydro-generation.
After exploring the available options the Energy Observer team took the decision to fit Eco*Stars, assessing them as being the best option to work with the crafts new “wings”. They are delighted with the results; “The wings and new propellers, in particular, enabled the boat to reach 14 knots in heavy seas.”
Autoprop Eco*Stars work by using their unique auto pitching abilities to match the constant torque that the electric motors provide throughout their rev range. This ensures that the craft is always obtaining the most efficient propulsion in terms of propulsive energy and economy and both at the same time. When purely sailing, and if maximum speed is not essential, the Eco*Stars can be left to turn in the vessels wake providing additional charging for the batteries.
