Versatile Jack K. handles multiple roles at the dredge site
Having made the decision to invest in three dredge tenders, Weeks Marine of New Jersey developed a design they termed a modified lugger tug.
The result, according to Shaun O’Brien, Weeks’ senior port engineer of towing and project manager during construction, is a twin-screw tug as multifaceted as a Swiss Army knife.
“The intention was to develop a small versatile vessel that could support dredging operations, transport a significant amount of fuel water, and perform towing operations to mobilize job sites,” O’Brien said.
The 62.5-foot Jack K., delivered from Rodriguez Shipbuilding in April, is the first of the series. The second tug is scheduled for delivery this summer. The third is a 78-by-30-foot triple-screw vessel due this fall. It is larger and more muscular than the preceding two to handle larger equipment and barge tows.
“The tug Jack K. is the first new build for Weeks Marine Towing since the tug Candace in 2005,” said Benjamin Peterson, towing division manager for Weeks Marine.
Jack K., named for a grandson of company president Richard Weeks, is fitted out for assisting dredges, towing, pushing, anchor handling, moving pipe and performing other dredging duties. Although it will primarily work along the Gulf of Mexico and Atlantic coast, the tug carries an Oceans COI for towing equipment offshore.
Joey Rodriguez has a long history of building shallow draft, lugger-style tugs at his Bayou La Batre, Ala., shipyard. He was forced to shutter the yard when the oil price collapse a few years ago resulted in a glut of oil transportation and supply vessels. Last year, he lifted the shutters in response to multiple orders, culminating in the Weeks’ contract.
One notable feature of the Rodriguez tug is the adaptable fishtail rudder, which is customized on each vessel to address the boat’s mission and the customer’s budget. Although the fishtail rudder design influences the boat handling characteristics, offsetting the rudders inboard is the largest contribution to better maneuverability.
“Offsetting the rudders inboard enhances the walking ability of the tug tremendously,” Rodriguez said. He noted that extending the leading edge of the rudders also contributes to what he calls a maximum performing rudder design. “After 43 years building boats, you learn a little bit about designing rudders.”
Peterson, also impressed with the tug’s maneuverability said, “She has a balanced feel with great rudder power, which allows the tug to utilize all of the vessel thrust to work in the tight confines of Weeks Marine dredging and construction sites.”
Dave Tuck, a Weeks engineer and project manager on the Jack K., agrees the handling is outstanding.
The wheelhouse has 360-degree visibility and four steering stations: center console, port and starboard wings and aft console. The stern station is fitted with a complete electronics suite and controls for operating the anchors and the Coastal Marine Equipment towing winch in all weather conditions.
The towing winch is also utilized for handling anchors via an anchor chute with roller, centerline at the stern rail. The winch has two drums, the larger wound with 1,200 feet of 1.25-inch towing wire, and a smaller drum with 500 feet of 1.25-inch wire for anchor handling. On the bow, there are two electric Nabrico deck winches for facing up to barges.
The three tugs have a host of characteristics to combat the elements and the rugged nature of dredging work. The hull and side shell are made of half-inch plate steel and the steel decks are 3/8 inches thick. The hull protection, provided by M&M Bumper Service of Bourg, La., is heavily protected from the wear and tear of handling anchors and pipe connections. The tire system is directly connected to the hull, eliminating the use of chain mounts that cause hull and tire wear.
All deck connections, handrails and stern cap rail are stainless steel, and all interior water piping is welded/flanged stainless steel to prevent leaks.
“We have designed a backup battery system powered by lithium ion batteries, which maintains the electronics, interior communication, and lighting,” O’Brien said. The interior lighting, half of which is on a backup system, are slim line LEDs manufactured by Macris Industries.
Propulsion comes from two Cummins QSK19-M main engines coupled to Twin Disc MGX 5222 gears with a 6.10:1 reduction ratio for 1,500 total horsepower. The 66-by-54-inch stainless steel, four-bladed Kahlenberg wheels are pitched for torque rather than speed. Electrical power comes from a pair of Cummins QSB7-DM-powered 60-kW generators.
“It’s really nice having an all-Cummins package for lower maintenance and operating costs,” Tuck said.
Crew comfort and crew endurance were a consideration throughout design and construction, according to O’Brien and Peterson. Accommodation is for six crew members in three staterooms. The interior cabinetry is custom built with hardwood panels and Perko hardware and the countertops are granite. The floors are a .75-inch Dex-O-Tex system with a rubberized overlay.
“This flooring is robust, reduces engine room noise, and provides a comfortable walking surface,” said O’Brien.
The practical reward for attending to the comfort of crew members is less fatigue and higher morale. To that end, all of the bunks are fitted with a pillowtop twin XL mattress and television sets. Channels can be selected separately from all four cabins and the galley. Satellite internet and television are connected via KVH V7 and TV 5 domes. The appliances in the galley are commercial grade with stainless exteriors.
Weeks Marine, one of the largest marine contractors in the United States and Canada, celebrated its 100th anniversary in 2019. The company’s dredging division owns and operates a large and diversified fleet of dredging and support equipment. A few recent new builds include the suction dredge C.R. McCaskill, built at Weeks Marine’s yard in Houma, and the trailing suction hopper dredge Magdalen, built at Eastern Shipbuilding.
The 78-foot triple-screw dredge tender under construction at Rodriguez, with greater tankage capacities and a larger aft winch, will be capable of larger and longer tows.
Meanwhile, Weeks expects to have a good sense of Jack K.’s prowess in short order.
“We’re leaving tomorrow morning for a dredging project in Tampa,” O’Brien said during the April 16 christening in Houma, La. “We should have a very good idea of the capabilities in the next few weeks. We designed these boats to be rugged and have a long career with Weeks.”