November 11, 2013
PAIR OF FULLY ROTATING ELECTRIC-POWERED PROPELLERS
THE ENGINE ROOM
Hello, Welcome Aboard!
This summer after a rapid North Atlantic crossing, direct from Kohler Engines in Kohler, Wisconsin, L’Hermione’s pair of electric propulsion engines arrived in Rochefort. These propulsion engines are not only capable of furnishing necessary electricity on board but, above all, fulfill required propulsion in dangerous conditions. Although our French tall ship is outfitted with an imposing array of main sails, jibs and top sails, L’Hermione also requires modern motors to carry out any maneuver, entering and leaving ports or, if there’s no wind, to continue moving in case of dangerous seas or destructive storms.
L’Hermione is the first large sail replica in the world outfitted with this pair of fully rotating electric-powered propellers (See Photo). Instead of installing traditional, fixed, unidirectional propellers on the aft hull, L’Hermione’s designers selected, for a variety of advantageous considerations, an innovative approach that avoids any risk of water leaks compromising electrical connections or chancing excessive vibrations, while simultaneously assuring L’Hermione’s permanent access to power and propulsion.
Each propeller is powered by its dedicated Kohler generator. (See Photo)
Each of the two Kohler motors can generate between 300 kW to 400 kW. An auxiliary generator with 85 kW capacity, powered by John Deere, handles everyday needs. The main generators’ power allows the frigate’s economical speed of approximately 7 knots (over 8 miles per hour,) employing only 50% of the generators’ total power. Sailing into winds of 50 knots or more, it can still go forward on full power.
Once the Kohler equipment arrived in Rochefort, the installation of the generators into the ship’s hold cleared by only a matter of inches. (See Photo)
Given the dimensions of the entrance to the hold, it was necessary to un-couple each motor from the generators in order to drop each piece into the sub-deck for re-coupling and final installation in L’Hermione’s engine room. (See Photo)
And here is the engine room with the generators fully operable, with the auxiliary placed in its sound proof shell.
L’Hermione’s diesel fuel tanks are likewise installed with the diesel-powered electric motors present and ready for service. The electric cabling between the genrators and the engines will be installed next. (See Photo)