New Aluminum Pilot Boat Built To Handle Wild Water.
When Kvichak Marine Industries, Seattle, Wash., undertook to build a 73 ft. pilot boat for the Columbia River Bar Pilots Association, the boat and its machinery suite had to be designed and constructed not only to survive rough water, but to be able to turn completely over and right itself. This is a common occurrence for the U.S. Coast Guard lifeboats used in the area.
"We not only had to use scantlings strong enough to survive the pounding, but every piece of machinery on the boat had to be bolted down to survive a rollover," explained Dave Weed, Kvichak project manager on the M/V Chinook project. The M/V Chinook was designed to replace the Peacock, a 30-year old pilot vessel.
The M/V Chinook is powered by a pair of Detroit Diesel 16V2000 diesel engines rated 1285 hp at 2100 rpm, which were supplied by Pacific Detroit Diesel Allison. The engines drive Hamilton 651 water-jets through DDA 6619SC marine gears with a 2.03:1 reduction. This combination gives the vessel a top speed of 29.95 knots and, with a pair of 550 gal. integral fuel tanks, a range of 250 nautical miles at a 25 knot cruising speed.
Required in the design specifications was stability that allows positive righting through 180[degrees]. Kvichak had to prove this ability before delivery of the vessel, which the company did in a dramatic test in front of its plant on Seattle's ship canal. A Foss barge crane lifted a series of belts rigged to one side of the Chinook, turning the vessel over 180[degrees]. When the straps were released, the vessel successfully righted itself. Because of its low center of gravity, superstructure buoyancy and hull design the Chinook passed the stability test with flying colors.
"Not only was all equipment secured -- as displayed by the lashings across the batteries for instance -- but every piece of gear on the boat had to be bolted down to stay put," Weed said. "The crankcase breather, which is normally a recirculating system, was replaced by a direct, onboard venting system. Further, the engine air intake and exhaust were positioned so that at no point could water flood the engine room.
The designer of the vessel was Camarc LTD of Worthing, West Sussex, England. The vessel has an overall beam of 21.3 ft. and at full load displaces 50.9 tons. The vessel can accommodate two crew and six pilots. Cabin outfitting includes an aft cabin with two bunks and a day galley, although the vessel will normally operate as a day boat based in Astoria.
The hull was designed with a double-chine hull for stability and high speed capability in adverse sea conditions, Weed pointed out. Control is enhanced by a breakwater structure ahead of the pilothouse that increases visibility in rough seas.
The vessel was built of marine aluminum alloy with the main structure requiring ABS design approval. Three Hamilton electronic control stations include a full width command console and matching stations port and starboard.
"The Bar has been referred to as the graveyard of the Pacific," said Capt. Wayne Stolz. "We demand a robust vessel that we can safely work the Bar with-- we are optimistic the team of Camarc and Kvichak has delivered such a vessel to us.
Deck equipment includes a custom articulated platform at the stern for recovering a man overboard; an articulated A-frame hoist amidships; aluminum quick access hatches on deck; and a Lexan escape hatch aft. Handrails are constructed of heavy-duty welded aluminum, with the forward railings where pilots stand for boarding ships heated to be free of ice. Deck surfaces at boarding areas utilize 1 in. rubber matting, which is also heated.
Electrical outfitting includes six 8D and four 4D sealed batteries for the 24 Vd.c. supply and two 32 kW Northern Light generators for the 120/208 Va.c. supply
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|Comment:||New Aluminum Pilot Boat Built To Handle Wild Water.|
|Publication:||Diesel Progress North American Edition|
|Article Type:||Brief Article|
|Date:||Aug 1, 2001|
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