Two big, liquefied natural gas-capable, azimuthing stern drive tractor-style tugs have joined the fleet of conventional twin screw tugs at Harbor Docking and Towing in Lake Charles, La.
The new tugs, Ted and George, at 105 feet in length and 6,754 hp, are heavy lifters, built to increase the companyâ€™s ability to assist the larger ships, primarily tankers, calling at Lake Charles.
The modern tractors have been years in the planning and building stages, with further delays caused by shipbuilding problems related to Hurricane Katrina and the backlog of projects at the Main Iron Works shipyard in Houma, La.
â€œBefore the arrival of these tugs, we were working maximum power for ships coming into Lake Charles,â€ said Dwayne Chatoney, vice president and operations manager of the company. â€œBut now the pilots like these new tugs because they have enough horsepower so that there is some reserve when they need it.â€
The Port of Lake Charles hosts a Whoâ€™s Who list of refiners producing petrochemical products. Tankers and (lately) LNG carriers enter the Calcasieu River from jetties extending out into the Gulf of Mexico and transit the 32-mile channel to facilities lining the river and the lake.
|The first of two new ASD tractors in the fleet of Harbor Docking is a 6,754-hp bruiser of a tug capable of handling the largest LNG tankers calling at U.S. ports today.|
â€œNormally we assist loaded tankers from the Intracoastal waterway to the crude oil terminals at Clifton Ridge, a trip of about 12 miles,â€ said Chatoney. â€œThese new boats were built specifically for tankers, but they are versatile tugs that can handle anything from a Q-Max LNG vessel down to the handy-size bulk carriers.â€ (Q-Max tankers are the newest and largest class of LNG tankers ever built, measuring more than 1,100 feet in length and some containing cargo regasification capability.)
Increasingly at Lake Charles and elsewhere, pilots are being called upon to guide bigger ships into the same small spaces, and to do it without mishap to environment or docking facility.
â€œWhat makes these boats really work is their maneuverability,â€ said Chatoney. â€œGiven the size of the boat, they have a quick response and handling much like a smaller ASD tug.â€
Harbor Docking and Seabulk Towing seem to handle the bulk of ship-assist work in the port, with Harbor Docking handling more of the oil and chemical tankers, but things may be changing with the arrival of more LNG tankers.
Seabulk Towing moves most of the LNG traffic at the Trunkline LNG terminal, a Panhandle Energy company, located nine miles south of Lake Charles in Cameron Parish. The facility came on line in 1981 and expanded in 2006.
However, with additional LNG terminals opening, it is reasonable that Harbor Docking, with these two new ASD tugs, may have plans to capture its share of the LNG tanker business as time goes by.
|Starboard console includes z-drive controls, a variety of monitoring systems, winch controls and communication equipment.<|
The new tractor, Ted, is named after Ted Dugey, a long-time supporter of the company. The tug, George, is named after George Carpenter, the former Lake Charles Harbor Pilot who founded the company in 1953. The tugs were built at Main Iron Works.
â€œWe traveled nationwide looking at tugs and looking at tug designs, and ended up in New Orleans on Bisso Towboatâ€™s Cecilia B. Slatten,â€ said Chatoney. â€œAs it happens, the Cecilia B. Slatten and others in the Bisso fleet were built at Main Iron Works in Houma.
â€œWhat we really liked about her is her 360-degree line of site. You can see the quarter bitts, the winch, the bulwarks, all around. Thatâ€™s important when you are coming alongside. Iâ€™ve seen a lot of tugs where you are blind coming alongside.â€
The original tug plans by naval architect Greg Castleman, of Castleman Maritime, were modified to accommodate an increase in both horsepower and z-drive units, and for the American Bureau of Shippingâ€™s (ABS) Escort Notation. These design changes included adding a box keel measuring 73-feet long and lengthening the boat by 5 feet.
Harbor Dockingâ€™s marine superintendent, Bill Milstead, and his assistant, Douglas Pierce, began the process of rebuilding four EMD engines to power the vessels, a step-up in propulsion dimensions and shafting arrangements that required lengthening the hull.
|Crew and staff gathered in the wheelhouse include, left to right, John Lanier, Richard Mott, Carl Johno, Toby Fontenot, Dwayne Chatoney and Steve Labobe.|
â€œThe original drawings were for the hull to be 100 feet by 38 feet, with 4,000 horsepower coming from roots-blown EMDâ€™s,â€ said Milstead. â€œWe stepped up the horsepower to 6,754. The z-drives were originally Rolls-Royce US 205s, which are about nine feet in diameter. In stepping up the horsepower to 3,377 per engine, we had to move up to the Rolls-Royce US 255 z-drives, which are about 12 feet in diameter. The main engines had to be moved forward one foot to allow us to take out some of the angle in the z-drive shaft,â€ he added.
The extra 5 feet were added to the length to accommodate the larger z-drives and to provide space for a FiFi-1 firefighting system, comprised of two Caterpillar engines powering Nijhuis fire pumps. â€œThree feet was added amidships and two feet was added in the stern between the back of the z-drives and the transom,â€ said Milstead. â€œThe main deck house was made one foot wider on each side in order for the larger exhaust mufflers to fit in the stack.â€
Engineers and technicians at Harbor Docking are all comfortable with EMD power, said Milstead. â€œWe are operating 10 EMD engines in our fleet at the present time,â€ he said. â€œI myself have been operating EMDs for about 30 years. In my opinion there is nothing better. We change lube oil and filters every 3,000 hours. The insides of the engines stay as clean as when they were new. At about eight years of service we have to remove all the heads and replace the head gaskets. We get about 60,000 hours between overhauls, and even then they are not in that bad of shape,â€ said Milstead.
â€œThe engines in the Ted and the George are EMD 16-645-E7B and were rebuilt with new Tier 1 emissions complaint power packs. They have four-pass after coolers and a high capacity turbo charger. EMDs run at 900-rpm and have plenty of low-end torque. I have heard of other tractor tugs with different make engines that would actually kill the engine when the z-drive was engaged. Believe me you donâ€™t have this problem with an EMD.â€
Both vessels are ABS A1 Towing Vessel, Escort Notation and AMS, bollard pull and FiFi-1 certified. The bollard pull is expected to be 90 tons, according to the company. The generators are both John Deere 99 kW.
|A short cardon shaft with universal joints is used to help make the connection between the engine and ASD drive unit.<|
On the bow is a 50-hp Markey electric hawser winch, type DYSF-48, with full render-recovery, line-tension display and data-logging controls in the wheelhouse. The render-recovery feature has become common on most new tractor-style tugs. The concept is to prevent intermittent high line loads and slack line conditions by utilizing sensors that allow the winch to maintain a constant line tension. The winch can respond to changes in load by paying out (rendering) more line as the ship separates from the tug, preventing high line loads, or spooling in (recovering) line as the tug and ship draw together, thus preventing slack lines.
The line-tension display keeps the operator aware of winch actions during ship handling operations and the data-logging system records them. Winches on the new tugs are loaded with 400 feet of 9-inch Amsteel Blue line with another 50 feet of pennant.
Harbor Docking and Towing is the oldest tug company operating in Lake Charles. The three twin-screw tugs; the 3,200-hp Edith, built in 1977; the 3,900-hp tug Allan, built in 1980; and the 4,800-hp tug Carl, rebuilt in 2000, are in pristine condition. The company employs about 30 people, most of them involved with the boats. â€¢