New Commercial Fishing Boat: Performance Through New Design
St. Elmo Marine of Fort Myers, Fla., in an effort to ride out the recent pleasure boat business slump, turned its focus to new designs for niche markets. The result: a revolutionary new commercial fishing boat, which entails state-of-the-art hull and propulsion solutions. At press time, St. Elmo Marine had a letter of intent for 30 boats from an international buyer.
"We realized that the pleasure boat industry was soft, and to be honest, we were having a tough time," s a i d Skip J a t k a u s k a s of St. Elmo Marine. So he, along with designer Charles Jannace, came up with a new era of commercial fishing boats, vessels that featured systems and technologies to make the smaller boats as productive, yet more economical, than older, larger vessels, said Mr. Jatkauskas. COMPOSITE HULL DESIGN The St. Elmo 36 vessel is a 36-foot vessel available in three hull designs: full displacement; planing; and a combination of the two.
Also available in a 68-foot version, the new vessel line utilizes state-of-the-art hull technology from the yacht industry; constructed using a foam cored hull, which provides tremendous stability while incorporating less internal framework. The planing hulls are speed hulls, requiring large amounts of horsepower and fuel to help the boat ride over the water. On the other hand, the full-displacement hulls require little horsepower and fuel to propel the vessel through the water. The St. Elmo moves through t h e water at eight knots, leaving hardly a wake.
With 4,000 pounds of ballast, stability is t h e norm and rolling tendencies are reportedly eliminated.
PROPULSION The St. Elmo was designed from the beginning as a true commercial fishing trawler, a vessel that would stay level on her lines regardless of the hold being full or empty. To achieve this, the engine was placed at the stern, away from the hold and far away from the pilot house and crew.
This was made possible by the drive belt assembly and a Twin Disc MG-506 transmission that transfers power from the 120-hp diesel to the prop shaft via a Kevlar Fiber Chain Belt, supplied by Gates Rubber Company. This setup in the back also provides unlimited engine access for routine maintenance. Besides aiding the handling of the vessel, the engine arrangement provides for big fuel savings, the manufacturer claims.
By incorporating the belt drive propulsion system, the St. Elmo is able to achieve a 4:1 reduction to the propeller, which in essence allows the boat to t u rn a bigger wheel using less horsepower, Mr. Jatkauskas said. The system can drive the St. Elmo at hull speed (about eight knots) using about 30 percent of the horsepower, allowing the vessel to travel 4.25 nautical miles per gallon. On the basis of an average usage of 2,500 hours per year, the boat would consume only 4,000 gallons of fuel at an approximate cost of $6,000, Mr. Jatkauskas estimates.
THE HOLD Contrary to its small size, the vessel provides big advantages that make it efficient. St. Elmo Marine can deliver the "complete package" to potential owners, including a state-of-the-art cooling system for the fish hold which allows operators to keep more of the catch fresh, said Mr. Jatkauskas. The 683-cubic-foot hold is capable of holding 15,000 pounds of product. The hold is uniquely placed in the center of the vessel, another design feature that allows the boat to remain level on her lines regardless of whether the hold is full or empty.