New Era in Nautical Propulsion
A new invention has appeared, called the “Hirudine Propeller"(from Hirudo, the leech), which aims to supersede the screw, paddle, and all other ship propelling contrivances yet practically known, and claims to inaugurate a new era in nautical propulsion, paralleled only by the introduction of steam itself; and whilst it can be used either for propelling or steering power, it is also applicable for an economical and powerful furnace blast. As steam, in supplanting manual, horse, and other powers, demanded new agents through which to develop its force, and found them in paddles, screws, & etc, so these appliances, after many transitions of form and mutual adaptations, seem at length to have
reached their highest practical development ; and now in turn the "Hirudine " discovery presents itself in the theatre of mechanical action, and with its inherent aqua motive-power of from one hundred to five hundred miles per hour, demands only of Science a prime mover that shall render available this hitherto undreamed-of velocity.
The "Hirudine" adopts for its model the leech, is in simple conformity with true mechanical principles, and may be thus described:
A flat, many-jointed, or elastic band (representing the leech), is extended edgeways to the horizon in a curved undulating line, within a square sided chamber or tube, formed through the whole length of the vessel below the water line, and open at both ends. The vessel is -built without distinction of stem or stern, to move in either direction. The undulatory action is pro¬duced by rods passing at regular distances from the hand to cranks or eccentrics, set in a spiral series on a shaft, which runs parallel to the tube, and thus at each revolution raises and depresses the band in a continuous wave-like movement throughout its entire length. By this process, the whole column of water in the tube is discharged with great impetus from one of the ends, and the ship is impelled on-wards in the opposite direction. It is calculated that in an average-sized steamer, with from 12 to 20 revolutions per minute, the water is drawn into, and ejected from the tube in a constant unbroken column, and at a rate of velocity from 50 to 90 miles an hour, according to the length of the vessel, and this without danger, strain, or even vibration, no portion of the machinery moving at a higher speed than from 100 to 200 feet per minute. Many advantages are alleged to attend the adoption of the "Hirudine Propeller," and amongst them the rapidity of passage, resulting from a velocity at least double that of any existing vessels, will economize space, by transferring to cargo much of the large proportion com¬monly sacrificed to fuel. Another important gain is secured in the greatly diminished friction and wear of machinery, arising from the comparatively leisurely action of the engine.
Sources: New York Journal 1856, The Mechanics' Magazine October 1855