Model-bow tugboats capable of inland, offshore operations

Lady Loren is one of three model-bow boats operated by LA Carriers. The three-screw design means the vessel can operate effectively even if it loses one of its engines. Courtesy LA Carriers

The model-bow tugboat, a combination towing and pushing vessel, is not exclusive to Louisiana, but close to it. There are a smattering among her Gulf Coast neighbors, Mississippi, Alabama and Texas, and a few on the Atlantic Coast, but the Pelican State is where the design shines, pushing barges along the inland waterways and bayous that vein the wetlands and towing them offshore in the Gulf of Mexico.

LA Carriers, of Cut Off, La., has a fleet of five boats, three of them model-bow vessels. Russell Plaisance founded LA Carriers in 1987. The company’s latest model-bow vessel, Lady Loren, joined the fleet this winter. “I’m competing against the rail lines," said Plaisance. “But they can’t beat the 2,800 tons of product that this boat can tow in two barges. This new boat has a contract to tow corn syrup coming from Memphis to Tampa Bay for Cargill."

The 82-by-29-foot Lady Loren is powered by three Cummins Tier 2 QSK19 mains, 1,980 hp total, running at a 6:1 ratio through Twin Disc gears shafted to 63-by-66-inch propellers in nozzles.

Plaisance chose Simplex Dripless shaft seals for the stern, where the shafts pierce the hull and meet the water, explaining that they prevent seepage into the highly regulated Florida waters: They “are very expensive but last a long time. They don’t eat themselves up like the old packing seals that would eat into the stainless steel and cause continual leaking."

LA Carriers owner Russell Plaisance (standing), with Kaitlin Olivia Capt. Steven Winstead (right) and deck hand Thomas Shaw. Brian Gauvin

The choice to go with a triple-screw propulsion configuration on both Lady Loren and Karen Koby, built two years ago, was to get more horsepower when towing offshore, and to keep the shallow draft advantage for inland pushing. And there are other reasons for having three engines.

“If you lose one engine, you still have two. You’ve only lost one-third of your horsepower, not one-half like you would with a normal twin screw. It’s like an insurance policy," said Plaisance.

To accommodate changing out engines, Lady Loren has a large fidley — a partially raised deck over the engine room near the exhaust stack — fitted with a 2-ton traveling crane capable of lifting any one of the 1.5-ton engines and locating it under a central hatch, for a six-hour engine change out.

She has a Smatco split drum winch on deck powered by a 110-hp diesel. The larger drum has 2,000 feet of 1.5-inch wire rope and the smaller one has 1,200 feet of 1.5-inch wire. A pair of stainless steel tow pins are tapered to help keep the towline in place. The aft cap rail is stainless steel. There is an elevated wheelhouse perched atop the main wheelhouse with a 35-foot line of sight for a good view over a tow of empty barges.

Wesley A, a 6,300-hp Z-Tech tug designed by Robert Allan and delivered by Main Iron Works in 2007, transits the Barbours Cut section of the Houston Ship Channel. Brian Gauvin

Lady Loren was on an offshore tow to Haiti, and Karen Koby was also on a job, the day I visited Plaisance and Steven Winstead, captain of the 75-by-26-foot Kaitlin Olivia, 10 years old, but looking to be just 2.

“We’re modernizing the fleet, getting rid of the old boats and building new ones," said Plaisance. “With all the new rules coming, and the Coast Guard starting to inspect the vessels, it will take a lot of money to fix up the old boats. It’s harder to redo something than build new. It’s like redoing an old house. You spend a lot of money and you still have an old house. And all the new equipment and electronics is so much better than it used to be." The model bow is designed primarily for offshore towing, taking moderate seas much better than the blunt bow and low profile of a conventional pushboat. Model-bow boats also usually have propellers in nozzles that generate more horsepower for pushing though the seas with better handling characteristics on the towline. The short stern with the winch far back on the stern allows more control of the towline. They have a flat and fendered bow stem that acts as a single push knee, two knees being the norm on conventional pushboats.

The versatility of both towing and pushing barges gives the design a leg up in the rough and tumble competition of water transportation. The big line-haul boats running product downriver drop their tows at the fleeting operations lining the river between Baton Rouge and New Orleans. Once the tows are broken up according to cargo and destination, the barges are picked up by smaller towboats and distributed to their next staging area.

Most of the cargoes are pushed to their destination along the inland waterways. However, those going to places like Tampa or the Caribbean are the meat of companies such as LA Carriers, utilizing the added component of towing from the stern in open water.

The barges are pushed from New Orleans, along the Gulf Intracoastal Waterway (GIWW), then remade into stern tows to cross the Gulf from Pensacola or Apalachicola, Fla., to Tampa and beyond.

Mate Bill Hadley throws a line as the Z-Tech tug Lamar ties up at Galveston’s Pelican Island. The 98.5-foot tug’s two Caterpillar 3516C mains driving Shottel Z-drives give it a bollard pull of 75 tons. Brian Gauvin

“We go to Tampa, Jacksonville, Norfolk, Mexico, Haiti, Dominican Republic, Jamaica, Puerto Rico," said Plaisance. Typically about 25 percent of the hull length on a model-bow is bow, and making up the tow so that the barge doesn’t shift on only one knee is critical. With the push knee centered on the stern of the tow, push wires (face wires) are run, like the edges of a fan, forward from 25-ton Parker winches on the stern deck of the boat, to cleats on the stern corners of the barge, then back to button cleats near the quarter bitts on the tug, and picked up with the winch. Then, jockey wires are run out from button bitts, just forward of the quarter bitts on the boat, to the stern corners of the barge, wrapped around cleats, and joined at the center of the barge with a tow ratchet and cinched up. The jockey wires stabilize the tow and prevent it from sliding sideways on the knee. The products handled by LA Carriers are diverse and include pipe, steel, dirt for baseball diamonds and perhaps most unusual, jets for the Air Force.

“That was a funny looking tow," Plaisance chuckled.

Typically Kaitlin Olivia pushes two 200-by-35-foot stainless steel-lined tank barges, custom built for transporting food product, filled with corn syrup produced by Cargill. American Commercial Barge Lines folds the barges into huge line-haul tows and transports the syrup down the Mississippi from Tennessee and Missouri to New Orleans. From there, LA Carriers’ model-bow boats make up their tows and push the syrup along the GIWW to Pensacola, remake the barges into a stern tow and cross 622 miles of the Gulf to Tampa. The syrup is used to sweeten such products as soft drinks and candy.

For the crossing, a Markey double-drum towing winch runs out 1,500 feet of 1.5-inch wire cable slotted through a roller on a Texas tow bar. The second barge follows on 300 feet of 2.75-inch polypropylene rope with a bridle at both ends. Plaisance explained that when he got the first syrup contract with Kaitlin Olivia, it was the first time the product had been moved by barge. “And with a 10-day deliver from Memphis to Tampa, we are moving it at less cost than trucks and in a more timely fashion than rail."

With a cup of “wheelhouse coffee" in hand, Capt. Winstead identified the weather as his biggest headache. “In the Mississippi Sound there is a lot of concern which way the wind will be coming from, and the tides and current, especially since the hurricanes have knocked out the barrier islands," he said. “There is actually a new cut that we call Katrina Cut at Dauphin Island. You’ll be coming down the channel perfect and (when you enter the sound) all of a sudden the swells come in and bust you up. They break the cables, and you have to go chasing after them this way and that way. So we have to put in before crossing the sound and make preparations, depending on what the water is doing.

“The typical pushboat with two knees has more control of the barges than we do with the model-bow, and they have flanking rudders that help them pivot the tow around a corner. We have to compensate with more power. In places where you have no room for error, you have to push hard to get through fast before you start getting pushed around by the wind and current. To make a long story short, you have to get her done."

“Right now business is miserable," said Plaisance. “If it would only be slow I’d say it would be good. But it’s bad. We’re down about 60 to 65 percent. The rates on the boats are down about 20 percent and there have been pay cuts of 10 percent and a lot of boats are tied up. But it’s going to get better. We have some work on the books and it looks like a decent summer."

Z-Tech tugs congregate along Texas coast

Quite a number of Robert Allan designed Z-Tech 7500 tugs have congregated on the coast of Texas. Currently six are working in Houston, Galveston and Freeport.

In 2007, Main Iron Works of Houma, La., delivered Thor and Wesley A to Suderman & Young Towing (S&Y) and Bay- Houston Towing (BH) respectively, both companies based in Houston, and both managed by G&H Towing of Galveston. Then Conrad Industries of Orange, Texas, delivered four identical Z-Techs last year, beginning with Evelena to S&Y, then Lexie M to BH, followed this year by Lamar to S&Y, and recently Hunter M to BH.

The new Texas tugs are the biggest of Robert Allan’s Z-Techs: 98.5 by 39.3 feet, 6,300 hp, powered by two Caterpillar 3516C mains driving Shottel z-drives, 75-ton bollard pull, FiFi-1 compliant with two FFS & Goulds fire pumps powered by twin Caterpillar C18 engines, propelling water at 5,300 gpm, Markey model DYSF-52 Escort Line Winch with automatic render/reverse and a 500,000-lb brake capacity and two John Deere 125-kW generators.

The Z-Tech tug combines the best characteristics of a tractor style tug and an azimuthing stern drive (ASD) tug. It has an oversized skeg for great tracking and the double-ended shape allows it to work a ship from either the bow or stern, depending on whether it is in escort or assist mode — in the tractor tug mode, towing in reverse from the bow; or tucked in under the flare of the ship’s bow, acting as an ASD.

G&H Towing has a partnership agreement with Moran Towing whereby Moran’s ASD tug Lynne Moran works with any two of the six Z-Tech tugs at the Freeport LNG terminal. However, Lynne Moran remains at the terminal on standby, while the Z-Techs can work in Freeport, Galveston, Texas City and Houston as needed.

Two more Z-Tech tugs are to be built, one each for S&Y and BH. They are destined for Sempra Energy’s LNG facility on the Calcasieu River near Lake Charles, La. They will be under Moran Towing management and will probably be built at Washburn Doughty of East Boothbay, Maine. •

By Professional Mariner Staff