Last fall, Kvichak Marine Industries, Seattle, was awarded a contract from the U.S. Navy for the design and construction of 10 MPF (Marine Prepositioning Force) aluminum, monohull landing craft.
Called the 40’ utility boat, the 44’×14’6” vessel will be part of the Navy’s Improved Navy Lighterage System. Elliott Bay Design Group, Seattle, provided detailed 3-D isometric assembly drawings.
The first of the new series was delivered earlier this year and the 10th is scheduled for completion next December.
The propulsion package includes twin, vibration-mounted Cummins QSM-11 engines, each rated at 660 hp at 2,300 rpm, ZF 325 FNR marine gears with 1:1 reduction ratios, and Hamilton 364 waterjets. Fully loaded at full throttle, the boats do a little over 30 knots, according to Kvichak’s Art Parker. Fully loaded at 80-percent power, the performance spec calls for a minimum of 25 knots. (Load capacity is five short tons or 30 personnel, each with 150 lbs. of gear.) Light, the new landing craft hits about 42 knots.
Each boat is also equipped with a 6-kw Northern Lights M673L2 generator for high-voltage loads.
Designed to carry cargo and people on and off beaches, the hull forefoot is reinforced with 0.25”-thick beaching plates over the bottom plate of the same thickness. All plate is 5083-H116. Side plate is 0.19”.
A single, hinged bow door swings out and down, providing a 58” opening flush to the deck. The bow door is operated by a 24V electric cable winch, which is backed up with a hand-cranked cable winch. Chain stays hold the load when the door is open.
Padded, vertical push knees on each side of the bow door are used for in-water pushing and for being pushed off beaches by backhoes or other heavy equipment.
Because the landing craft will be lifted on and off ships, each boat has four lifting eyes positioned to allow lifting without spreader bars. Each boat is also shipped with an aluminum storage cradle, which also has four lifting eyes, as well as TEU (20’ equivalent unit) container “twist lock” corner fittings to secure the cradle to the deck of a ship.
Troops and cargo are carried forward on the well deck, which can be enclosed with polyester fabric and clear vinyl windows. Removable aluminum benches with lap belts provide seating.
Parker said the first boat underwent extensive sea trials to quantify and verify performance and capabilities. The Navy’s PMS325 (Small Boats Project Office) team also made several site visits during construction of the first boat. “In general, they have pretty darn good scrutiny of what you’re doing,” he said. “You have to build them exactly as you said you would.”
As much as Kvichak appreciates the Navy’s business, it wants to maintain a strong order book for commercial projects too. To that end, the company recently began construction of two 72’×29’ aluminum catamarans for Luxury Marinas in Puerto Rico. Designed by Australia’s Crowther Multihulls, the Subchapter T boats will be capable of carrying up to 150 passengers at about 25 knots. For propulsion, twin Cummins QSK-19M engines, each rated at 880 hp at 2,100 rpm, will turn 5-bladed props through ZF gears. Delivery of both cats is scheduled for December. — Bruce Buls