Search Results for: Schottel

  • News

CEO Spotlight: A Tale of Two Shipyards

In the months following Hornblower’s selection by New York City as the operator of its new Citywide Ferry Service, speculation was rampant as to what shipyard or shipyards would be able to build the fleet of 19 ferries in less than a year’s time. Many of the traditional passenger-only ferry builders in the U.S. were fully booked or declined to tender an offer because of what one shipbuilder called “an impossible delivery schedule.”

When we broke the news in early July of the award of the boatbuilding contracts, the two Gulf Coast shipyards to emerge as the winners were Horizon Shipbuilding and Metal Shark Aluminum Boats. The selections caught many outside the marine industry by surprise because neither yard had built a passenger-only ferry to date.

One, Horizon Shipbuilding, is situated in Bayou La Batre, AL—the heart of the shrimp boat business. While the other, Metal Shark Aluminum Boats, is headquartered in Jeanerette, LA—known as “Sugar City” because of its local sugar cane crop and sugar processing mills.

While the selections might have raised some eyebrows among the general public, both yards have carved out impeccable reputations for meeting challenging production schedules for constructing boats and vessels in series for government and commercial customers. Both have a highly skilled, core workforce; both count the U.S. Navy and U.S. Coast Guard among their customers; and both are owned by confident, forward-thinking entrepreneurs.

Horizon Shipbuilding’s Travis Short
Travis Short, Owner and President of Horizon Shipbuilding, knows his shipyard can deliver. He points out that the shipyard built 40 vessels in a 20-month timeframe for a commercial offshore oil customer. Those boats, by the way, just so happen to be the same tonnage as the 149-passenger Citywide Ferry catamaran vessels.

He also cites a contract that Horizon Shipbuilding won to build ten 10,000-gallon-capacity oil barges after the Deepwater Horizon disaster. The barges were to be used in the cleanup in the Gulf and the shipyard had one month to deliver them.

“Our key people have been with us for a long time,” says Short. “They know how Horizon Shipbuilding operates. Building boats is what we do.”

The Gordhead Factor
A graduate of the University of Southern Alabama with a Bachelor of Science in Business Administration, Short started Horizon Shipbuilding in 1997 with his father, Travis Sr. While Short is fully confident in the ability of his core workforce, five years ago he felt that they could be more productive. “We weren’t doing poorly,” says Short, “but we just weren’t getting any better.” Short wanted to make improvements in workflow, reporting and resource management. That’s where he got the idea for Gordhead management software.

“We wanted to start by giving access to more information,” says Short. “With Gordhead, we created a software platform that brings together all of the information.”

Gordhead is an app that can be used on your mobile device. By using a modular-based system, it syncs with existing enterprise resource planning, scheduling and timekeeping software to provide project transparency and promote collaboration between production managers and workers.

“It’s all about better communication,” says Short. He says the use of Gordhead by management has allowed Horizon Shipbuilding to share information throughout the day on projects and do away with daily production meetings. Shorts says that what often holds up any production process is that someone is waiting on an answer before he can proceed with his work. “Gordhead wipes that out. It raises the level of communication, allowing the time for decision-making to get shorter. It gets rid of bottlenecks.” The software also allows greater transparency for an owner to check on the status of the construction of his vessel.

Cameron Clark, VP and GM, Hornblower NY, cited the use of Gordhead as one of the factors in selecting Horizon Shipbuilding as one of the builders for the NY Citywide Ferry project. Clark says the use of the Gordhead management software will allow Hornblower to stay connected with the team on the ground 24/7 and ensure the project stays on schedule.

Located about three miles from Mobile Bay, Horizon’s facility is made up of a West Yard and Main Yard, with nine steel buildings for steel and aluminum fabrication and construction. The construction and outfitting of modules and vessels is mainly performed in two 175 ft x 50 ft buildings. Horizon Shipbuilding also uses a huge 660-ton Travelift for the transfer and launch of vessels.

The key piece of the fabrication process is the ALLtra Model PG14-12 Shape Cutting Machine, which is a CNC-controlled gantry designed for cutting complex shapes for sheet or plate materials. It is capable of producing parts at high speeds and close tolerances and was used to cut precise jig patterns, allowing for innovative ways of rapid hull construction for the ferries. The machine is easily configured for plasma or oxy/fuel shape cutting processes and can be customized for special applications. Horizon’s application utilizes the Hypertherm HPR260 plasma cutter controlled by the Burny 10 LCD shape cutting motion controller using MTC ProNest 8 nesting software.

The current workforce at the shipyard is about 300, with about 125 of those dedicated to the New York ferry project.

The NYC Ferry Design
Designed by Incat Crowther, the new catamaran ferries will be 85 feet 3 inches long, with a beam of 26 feet 3 inches, and draft of 3 feet 4 inches. The ferries will also feature plenty of charging stations for the connected crowd, concessions, Wi-Fi and a space for up to 19 bicycles on board.

Each vessel will use two 803-hp EPA-compliant Tier 3 Baudouin 6M26.3 P3 main engines to help reduce diesel emissions and noise. Incat Crowther’s innovative hull design will help limit wake and maximize fuel efficiency, and the ferries will primarily be built out of aluminum further increasing fuel efficiency.

Each boat is expected to carry at least 149 passengers (some could have higher capacities). The vessel’s main deck will have seating for 123 passengers plus space for four wheelchairs and four strollers. The upper deck will seating capacity for 42 passengers.

“We are going to start out with a five-day-a-week schedule,” says Short, “and adjust if necessary. It is an ambitious schedule, but we’ll start delivering boats on their own bottoms starting in the early spring and finishing in the late spring.

“While these are the first catamaran ferries we’ve built,” he continues, “they are not the first passenger boats. We’ve delivered high-speed crewboats for Mexico and West Africa.”

Of course, the New York ferries aren’t the only game in town. Horizon also has five repair jobs in the yard, including river inland towboats, a research vessel, and 130 ft yacht.

It is also building two 100 ft x 40 ft escort tugs for McAllister Towing, New York, NY. Based on a design by Jensen Maritime, Seattle, WA, the steel-hulled tugs will be ABS classed and fitted with Caterpillar 3516E Tier 4-compliant main engines, driving Schottel SRP4000FP propulsion units. The tugs are to be delivered in early 2017.

Bold Plan, Bold Choice
New York Mayor Bill de Blasio’s plan to create the citywide ferry service—at a cost of $325 million—is a bold reimagining of the city’s future public transportation. The Mayor thinks that the ferry service when up and running would carry an estimated 4.5 million passengers in a year. All of the new ferries would be in service by mid-2017. At $2.75 per ride the ferry service would be affordable for the average New Yorker. The new citywide ferry service would be a crowning achievement for the Mayor just months before he stands for reelection in the fall of 2017.

Metal Shark’s Chris Allard
The choice of Metal Shark Aluminum Boats as the other shipyard to build the new ferries is a bold one, too. Metal Shark is owned by Chris Allard and Jimmy Gravois. A Long Island native, Allard joined American Marine Holdings after graduating from the prestigious Webb Institute. He later partnered with Gravois, owner of Gravois Aluminum Boats, to acquire Metal Shark in 2006.

Ten years later, Metal Shark has emerged as a premier builder of aluminum military craft for all of the branches of the U.S. military—Navy, Coast Guard, Air Force and the Army.

All of those boats are built at what Allard calls the Jeanerette “boat production facility” because it delivers almost a vessel on a daily basis. Back in 2011, Metal Shark grabbed headlines when it was awarded the contract to replace the U.S. Coast Guard’s aging Response Boat-Small (RB-S) fleet. The nearly $200 million contract of over 470 boats, was the largest of its kind ever awarded by the Coast Guard.

In 2014, Metal Shark took the next step in its growth with the acquisition of a 25-acre waterfront tract in Franklin, LA, a short drive from the company’s headquarters in Jeanerette. Located on the Charenton Canal, the Franklin yard, says, Allard, is designed for shipbuilding and provides direct access to the Gulf of Mexico. Recent deliveries include 90- and 75-foot catamarans and 60- and 50-foot catamarans. The Franklin yard has also built some 45-foot patrol boats.

Allard sees the New York City ferry contract as a springboard into growth into the commercial vessel market. “We’ve been primarily known as a military and government contractor,” says Allard. “This contract is part of a major company diversification.” In the coming months, Allard expects to announce a number of commercial contracts to build its largest vessels yet. The Franklin facility has enough capacity to build multiple vessels of 200 feet in length.

Engineering company at heart
“We are really an engineering company at heart,” says Allard. It says the company leverages technology, such as robotics, CNC cutting, bending, CAD software systems to stay focused on production efficiencies, controlling costs and producing quality products for the customer. These same engineering processes can be seen in the sheet metal, automotive, and aeronautical industries.

As for the New York City ferry contract, Allard says Metal Shark secured the business “the good, old fashioned way.” Allard says, “We’ve been working with Hornblower for more than two and a half years providing them the information and the tools they needed to secure the contract. We also showed them how we could replicate our building processes to construct the ferries.”

Metal Shark currently has about 200 workers between its two shipyards and might ramp up “a little,” says Allard. The company will also be able to shift some of the labor pool from one facility to the other based on project demand.

The Franklin yard is also benefitting from a Small Shipyard Grant from the U.S. Maritime Administration for $582,410, which will be used to acquire portable shelters and marine transporters.

“We were able to cut metal within 10 days of signing the contract,” he says. “We do most of our design work in-house with its naval architectural staff—but for the New York City ferry project, the design is owner-furnished from Hornblower. We are working on the same design as Horizon Shipbuilding in order to make the boats as absolutely identical as possible.”

According to Allard, Metal Shark (and Incat) are participating in a limited usage of Gordhead at Hornblower’s request for sending and receiving technical clarifications during the design phase of the project in order to minimize differences in interpretation of design clarifications by the two builders. He says that Metal Shark has its own advanced software, tools and processes for project management, engineering planning, production coordination and customer communications.

CEO Spotlight: A Tale of Two Shipyards

In the months following Hornblower’s selection by New York City as the operator of its new Citywide Ferry Service, speculation was rampant as to what shipyard or shipyards would be able to build the fleet of 19 ferries in less than a year’s time. Many of the traditional passenger-only ferry builders in the U.S. were fully booked or declined to tender an offer because of what one shipbuilder called “an impossible delivery schedule.”

When we broke the news in early July of the award of the boatbuilding contracts, the two Gulf Coast shipyards to emerge as the winners were Horizon Shipbuilding and Metal Shark Aluminum Boats. The selections caught many outside the marine industry by surprise because neither yard had built a passenger-only ferry to date.

One, Horizon Shipbuilding, is situated in Bayou La Batre, AL—the heart of the shrimp boat business. While the other, Metal Shark Aluminum Boats, is headquartered in Jeanerette, LA—known as “Sugar City” because of its local sugar cane crop and sugar processing mills.

While the selections might have raised some eyebrows among the general public, both yards have carved out impeccable reputations for meeting challenging production schedules for constructing boats and vessels in series for government and commercial customers. Both have a highly skilled, core workforce; both count the U.S. Navy and U.S. Coast Guard among their customers; and both are owned by confident, forward-thinking entrepreneurs.

Horizon Shipbuilding’s Travis Short
Travis Short, Owner and President of Horizon Shipbuilding, knows his shipyard can deliver. He points out that the shipyard built 40 vessels in a 20-month timeframe for a commercial offshore oil customer. Those boats, by the way, just so happen to be the same tonnage as the 149-passenger Citywide Ferry catamaran vessels.

He also cites a contract that Horizon Shipbuilding won to build ten 10,000-gallon-capacity oil barges after the Deepwater Horizon disaster. The barges were to be used in the cleanup in the Gulf and the shipyard had one month to deliver them.

“Our key people have been with us for a long time,” says Short. “They know how Horizon Shipbuilding operates. Building boats is what we do.”

The Gordhead Factor
A graduate of the University of Southern Alabama with a Bachelor of Science in Business Administration, Short started Horizon Shipbuilding in 1997 with his father, Travis Sr. While Short is fully confident in the ability of his core workforce, five years ago he felt that they could be more productive. “We weren’t doing poorly,” says Short, “but we just weren’t getting any better.” Short wanted to make improvements in workflow, reporting and resource management. That’s where he got the idea for Gordhead management software.

“We wanted to start by giving access to more information,” says Short. “With Gordhead, we created a software platform that brings together all of the information.”

Gordhead is an app that can be used on your mobile device. By using a modular-based system, it syncs with existing enterprise resource planning, scheduling and timekeeping software to provide project transparency and promote collaboration between production managers and workers.

“It’s all about better communication,” says Short. He says the use of Gordhead by management has allowed Horizon Shipbuilding to share information throughout the day on projects and do away with daily production meetings. Shorts says that what often holds up any production process is that someone is waiting on an answer before he can proceed with his work. “Gordhead wipes that out. It raises the level of communication, allowing the time for decision-making to get shorter. It gets rid of bottlenecks.” The software also allows greater transparency for an owner to check on the status of the construction of his vessel.

horizon slide

At left, Horizon Shipbuilding’s facility in Bayou La Batre, AL

Cameron Clark, VP and GM, Hornblower NY, cited the use of Gordhead as one of the factors in selecting Horizon Shipbuilding as one of the builders for the NY Citywide Ferry project. Clark says the use of the Gordhead management software will allow Hornblower to stay connected with the team on the ground 24/7 and ensure the project stays on schedule.

Located about three miles from Mobile Bay, Horizon’s facility is made up of a West Yard and Main Yard, with nine steel buildings for steel and aluminum fabrication and construction. The construction and outfitting of modules and vessels is mainly performed in two 175 ft x 50 ft buildings. Horizon Shipbuilding also uses a huge 660-ton Travelift for the transfer and launch of vessels.

The key piece of the fabrication process is the ALLtra Model PG14-12 Shape Cutting Machine, which is a CNC-controlled gantry designed for cutting complex shapes for sheet or plate materials. It is capable of producing parts at high speeds and close tolerances and was used to cut precise jig patterns, allowing for innovative ways of rapid hull construction for the ferries. The machine is easily configured for plasma or oxy/fuel shape cutting processes and can be customized for special applications. Horizon’s application utilizes the Hypertherm HPR260 plasma cutter controlled by the Burny 10 LCD shape cutting motion controller using MTC ProNest 8 nesting software.

The current workforce at the shipyard is about 300, with about 125 of those dedicated to the New York ferry project.

The NYC Ferry Design
Designed by Incat Crowther, the new catamaran ferries will be 85 feet 3 inches long, with a beam of 26 feet 3 inches, and draft of 3 feet 4 inches. The ferries will also feature plenty of charging stations for the connected crowd, concessions, Wi-Fi and a space for up to 19 bicycles on board.

Each vessel will use two 803-hp EPA-compliant Tier 3 Baudouin 6M26.3 P3 main engines supplied by Motor-Services Hugo Stamp, Inc., Fort Lauderdale, FL, to help reduce diesel emissions and noise. Incat Crowther’s innovative hull design will help limit wake and maximize fuel efficiency, and the ferries will primarily be built out of aluminum further increasing fuel efficiency.Baudouin 6M26 slide

Each boat is expected to carry at least 149 passengers (some could have higher capacities). The vessel’s main deck will have seating for 123 passengers plus space for four wheelchairs and four strollers. The upper deck will seating capacity for 42 passengers.

“We are going to start out with a five-day-a-week schedule,” says Short, “and adjust if necessary. It is an ambitious schedule, but we’ll start delivering boats on their own bottoms starting in the early spring and finishing in the late spring.

“While these are the first catamaran ferries we’ve built,” he continues, “they are not the first passenger boats. We’ve delivered high-speed crewboats for Mexico and West Africa.”

Of course, the New York ferries aren’t the only game in town. Horizon also has five repair jobs in the yard, including river inland towboats, a research vessel, and 130 ft yacht.

It is also building two 100 ft x 40 ft escort tugs for McAllister Towing, New York, NY. Based on a design by Jensen Maritime, Seattle, WA, the steel-hulled tugs will be ABS classed and fitted with Caterpillar 3516E Tier 4-compliant main engines, driving Schottel SRP4000FP propulsion units. The tugs are to be delivered in early 2017.

Bold Plan, Bold Choice
New York Mayor Bill de Blasio’s plan to create the citywide ferry service—at a cost of $325 million—is a bold reimagining of the city’s future public transportation. The Mayor thinks that the ferry service when up and running would carry an estimated 4.5 million passengers in a year. All of the new ferries would be in service by mid-2017. At $2.75 per ride the ferry service would be affordable for the average New Yorker. The new citywide ferry service would be a crowning achievement for the Mayor just months before he stands for reelection in the fall of 2017.

Metal Shark’s Chris Allard
The choice of Metal Shark Aluminum Boats as the other shipyard to build the new ferries is a bold one, too. Metal Shark is owned by Chris Allard and Jimmy Gravois. A Long Island native, Allard joined American Marine Holdings after graduating from the prestigious Webb Institute. He later partnered with Gravois, owner of Gravois Aluminum Boats, to acquire Metal Shark in 2006.

Ten years later, Metal Shark has emerged as a premier builder of aluminum military craft for all of the branches of the U.S. military—Navy, Coast Guard, Air Force and the Army.

All of those boats are built at what Allard calls the Jeanerette “boat production facility” because it delivers almost a vessel on a daily basis. Back in 2011, Metal Shark grabbed headlines when it was awarded the contract to replace the U.S. Coast Guard’s aging Response Boat-Small (RB-S) fleet. The nearly $200 million contract of over 470 boats, was the largest of its kind ever awarded by the Coast Guard.

In 2014, Metal Shark took the next step in its growth with the acquisition of a 25-acre waterfront tract in Franklin, LA, a short drive from the company’s headquarters in Jeanerette. Located on the Charenton Canal, the Franklin yard, says, Allard, is designed for shipbuilding and provides direct access to the Gulf of Mexico. Recent deliveries include 90- and 75-foot catamarans and 60- and 50-foot catamarans. The Franklin yard has also built some 45-foot patrol boats.Metal Shark 75 Franklin slide

At right, aluminum hull of 75 ft catamaran at the Franklin, LA, shipyard of Metal Shark Aluminum Boats

Allard sees the New York City ferry contract as a springboard into growth into the commercial vessel market. “We’ve been primarily known as a military and government contractor,” says Allard. “This contract is part of a major company diversification.” In the coming months, Allard expects to announce a number of commercial contracts to build its largest vessels yet. The Franklin facility has enough capacity to build multiple vessels of 200 feet in length.

Engineering company at heart
“We are really an engineering company at heart,” says Allard. It says the company leverages technology, such as robotics, CNC cutting, bending, CAD software systems to stay focused on production efficiencies, controlling costs and producing quality products for the customer. These same engineering processes can be seen in the sheet metal, automotive, and aeronautical industries.

As for the New York City ferry contract, Allard says Metal Shark secured the business “the good, old fashioned way.” Allard says, “We’ve been working with Hornblower for more than two and a half years providing them the information and the tools they needed to secure the contract. We also showed them how we could replicate our building processes to construct the ferries.”

Metal Shark currently has about 200 workers between its two shipyards and might ramp up “a little,” says Allard. The company will also be able to shift some of the labor pool from one facility to the other based on project demand.

The Franklin yard is also benefitting from a Small Shipyard Grant from the U.S. Maritime Administration for $582,410, which will be used to acquire portable shelters and marine transporters.

“We were able to cut metal within 10 days of signing the contract,” he says. “We do most of our design work in-house with its naval architectural staff—but for the New York City ferry project, the design is owner-furnished from Hornblower. We are working on the same design as Horizon Shipbuilding in order to make the boats as absolutely identical as possible.”

According to Allard, Metal Shark (and Incat) are participating in a limited usage of Gordhead at Hornblower’s request for sending and receiving technical clarifications during the design phase of the project in order to minimize differences in interpretation of design clarifications by the two builders. He says that Metal Shark has its own advanced software, tools and processes for project management, engineering planning, production coordination and customer communications.

Eastern delivers Z-Tech 2400 escort tug

AUGUST 23, 2016 — Eastern Shipbuilding Group, Inc. reports that its Nelson Street shipyard has delivered the escort tug Oceanus to Suderman & Young Towing. The vessel is the third in of

Tugs & Barges: Evolving with the market

Engineering company GTT has more than 50 years’ experience in the design of membrane cargo containment systems, but one project underway right now in Orange, TX, is quite unique. That’s because it’s the first Liquefied Natural Gas (LNG) bunker transport barge in the United States.

One of 118 GTT projects currently underway worldwide, the tank barge is taking shape at Conrad Orange shipyard, Aziz Bamik, General Manager of GTT North America, told delegates at Marine Log Tugs & Barges 2016 Conference & Expo held last month in Seattle. While Conrad has decades of experience building all types of tank barges—dirty oil, products, chemicals, and LPG—this is the first time that it is building a vessel with one of GTT’s Mark III Flex membrane tank technology. Following a certification process, Conrad signed a license agreement with GTT back in January 2015 to construct the Mark III Flex.

Designed to operate in inland waterways, bays, harbors, and U.S. coastal waters, the new 2,200 m3 tank barge will be used to refuel TOTE’s two 3,100-TEU LNG-powered containerships. The barge will travel about a mile from its mooring facility to fuel the two Orca Class containerships, which operate out of the Port of Jacksonville, FL to San Juan, PR. The barge is designed not as an Articulated Tug Barge unit, but rather to be towed by hawser wire, pushed or maneuvered by hip, says Bamik.

In anticipation of increasing demand for LNG as a marine fuel, Bamik also mentioned to the conference audience that GTT North America was working with Conrad on a larger Articulated Tug Barge unit that will have a capacity of 4,800 m3, with two GTT Mark III Flex Cargo Containment System tanks. The 319 ft x 62 ft barge would have cold LNG delivery with onboard reliquefaction.

COMING DEMAND FOR LNG
The interest in LNG as a marine fuel seems to have waned in the U.S. with the drop in the price of oil. As of today, five vessels burn LNG as fuel in the Jones Act market. Besides TOTE’s two containerships, the Harvey Power, the third in a series of six dual fuel Platform Supply Vessels for Harvey Gulf International Marine, New Orleans, recently entered service in the Gulf of Mexico under charter for Shell. Next year, Crowley Maritime will take delivery of two Commitment Class Container Roll-on/Roll-Off (CONRO) ships for Puerto Rico. Those are being classed by DNV GL. All the other Jones Act LNG fuelled vessels are being built to ABS class.

Additional LNG Ready classed tonnage delivered or being built by General Dynamics NASSCO in San Diego and Philly Shipyard Inc. in Philadelphia could grow the LNG-fueled Jones Act fleet if converted in the future. TOTE is also converting its two Orcas Class RO/RO ships for Alaska service in Singapore.

Globally, there are about 77 gas-fueled vessels in operation and another 79 confirmed newbuildings as of March 2016, according to Anthony Teo, Technology and LNG Business Development Manager, North America, DNV GL. “There are about another 50 LNG Ready vessels have been contracted,” Teo told delegates. He said that DNV GL estimates there will be 360 LNG fuelled vessels in operation by 2020.

The widespread adoption of LNG as a fuel, Teo pointed out, was is being hindered by the lack of gas fuel bunkering facilities in ports.

A panel of naval architects, liquefied natural gas reliquefaction technology providers, and regulators discussed more in-depth the current hurdles hindering the expansion of the adoption of LNG as a marine fuel for the tugs and towboats in the Jones Act market.

Panelist Rafael Riva, Marine Business Development Manager, ECA, Lloyd’s Register pointed out that the technology was well proven in Europe. The first LNG tugs, for example, were built in Turkish shipyard Sanmar for Norway’s Bukser og Berging AS and have been in service for Statoil AS since 2014. The DNV GL class tugs are equipped with lean burn gas engines from Rolls-Royce and Rolls-Royce azimuthing thrusters.

The LNG powered propulsion systems does require more space. The Shearer Group’s Engineering Manager Joshua Sebastian, PE, mentioned the complexities of integrating the necessary fuel tank, piping, and control systems required to burn LNG on the smaller towboat platform. Sebastian’s company, naval architectural firm The Shearer Group, has been contracted for the conversion of a 65-foot-long conventional diesel-powered towboat to burn LNG.

LNG-powered tugs also require small volumes of fuel with a dedicated delivery solution. Fueling can be accomplished either via tanker trucks, shore LNG storage tanks, portable gas fuel tanks or ship to ship or barge to ship transfer.

Panelist John Dwyer, Officer in Charge, Marine Inspection/Chief, Inspection Division at USCG Sector Puget Sound, provided the regulatory view on the development of LNG as a marine fuel in the U.S.

The U.S. Coast Guard has issued a number of policy letters and guidance on the design and operation of ships using LNG as a marine fuel, as well as ships and facilities transferring LNG as fuel. The U.S. Coast Guard has addressed designs and facilities on a case-by-case basis.

Waller Marine’s Beau Berthelot pointed out that his company has worked on a number of refueling solutions. Waller Marine, for example, has been granted an Agreement in Principle (AIP) by ABS for a new liquefied natural gas (LNG) and regasification articulated tug barge concept. The vessel has the ability to load LNG from existing LNG terminals, liquefaction facilities or traditional LNG carriers and transport the LNG to existing tanks, traditional LNG carriers, trucks or marine vessels using LNG as a fuel. The barge also is equipped for regasification of LNG directly to a pipeline or to a power plant. An additional feature will be the use of natural gas as a fuel in the dual fuel engines of the tug to drive the tug-barge unit.

The benefit of the LNG Articulated Tug and Barge Regas Vessel (ATB RV) is that it allows LNG to be moved and delivered more efficiently on a small-scale basis in locations where large LNG infrastructure would be cumbersome, costly and time consuming.

Another possible solution for small footprint applications mentioned by panelists David Grucza, Director, Drilling and Marine U.S., Siemens, and Michael Walhof, Sales Director, Distributed LNG Solutions, Dresser-Rand, a Siemens company, was Dresser-Rand’s LNGo system is a modularized, portable natural gas liquefaction plant. This point-of-use production plant is a standardized product made up of four packaged skids: a power module, compressor module, process module and a conditioning module. The natural gas consumed powers the unit and is also used as the process refrigerant to eliminate complexity and maintenance.

SHIPYARDS CONTINUE TO BE BUSY
Meanwhile, U.S. shipyards continue to book orders for conventionally powered harbor tugs and Articulated Tug Barge (ATB) units. The continued orders for ATBs, in particular, are in response to transport refined products in the U.S.

Just last month, Gunderson Marine, Portland, OR, secured an order to build two 82,000 bbl, 430 foot-long oceangoing tank barges for Harley Marine Services, Inc., Seattle.  The tank barges will be part of an ATB unit.

Gunderson last built a barge for Harley Marine in 2009.  Construction on the barges will begin this year, with delivery of both vessels set for the second half of 2017. 

As of press time, Harley Marine Services was negotiating with a Gulf Coast shipyard for the construction of the ATB tugs that would be coupled to the tank barges being built by Gunderson.

Over the past nine months, Gunderson Marine has delivered two 578 ft ATB oceangoing barges for chemical and oil service for Kirby Offshore Marine.

For its tank barges, Kirby Offshore Marine took delivery of two 10,000 hp ATB tugs from Nichols Brothers Boat Builders, Whidbey Island, WA. Speaking at Marine Log Tugs & Barges 2016, Nichols Brothers Boat Builders President & CEO Gavin Higgins said that ATBs enjoy several cost advantages over coastal tankers when it comes to moving refined products. Crew costs are far less, nine crew vs. 18 crew. Additionally, ATBs are more ship shape, offering speed advantages over towed tank barges.

The shipyard has also signed a contract with Kirby for two line haul tugs, as well as two 8,000 hp ATB tugs based on a design by naval architect Robert Hill of Ocean Tug & Barge Engineering. The companion tank barges are being built by Vigor.

FINCANTIERI BAY SHIPBUILDING
Fincantieri Marine Group’s Fincantieri Bay Shipbuilding (FBS), Sturgeon Bay, WI, has delivered the Articulated Tug Barge unit (ATB) Barbara Carol Ann Moran and the 110,000-barrel ocean tank barge Louisiana to Moran Towing Corporation, New Canaan, CT.

The 5,300-HP, 121-foot ATB tug Barbara Carol Ann Moran is certified ABS Class +A-1 Towing Service, +AMS, and is equipped with state-of-the-art navigation and communications technology. The Louisiana is 468 ft x 78 ft.

The ATB unit will work the East Coast of the United States and the Gulf of Mexico.

This is the shipyard’s third delivery to Moran under a 2014 contract, with a tank barge delivered in May of 2015, and another ATB—the tug Leigh Ann Moran and tank barge Mississippi—delivered December 1, 2015.  

VANE BROTHERS SERIES AT ST. JOHNS
Vane Brothers, Baltimore, MD, continues to invest in new tonnage. It has a long running newbuild program at Chesapeake Shipbuilding in Salisbury, MD, where it is constructing a series of 3,000 hp ATB tugs and has now added the second of eight 4,200 horsepower tugboats from St. Johns Ship Building, Palatka, FL.

The new tug, Hudson, is the second of Vane’s Elizabeth Anne Class, under construction at St. Johns Ship Building. Lead vessel of the class, the Elizabeth Anne, was delivered in January, while the third in the series, the Baltimore, is set for completion this summer.

The new tug will be paired with the Double Skin 601, the first in a new series of 55,000 bbl barges and will be followed later this year by the Double Skin 602, both built by the Conrad Deepwater South Shipyard in Amelia, LA.

“Our ongoing fleet construction program ensures that we have state-of-the-art equipment available to service all of our customers’ needs with the utmost safety and efficiency,” says Vane Brothers President C. Duff Hughes.

Designed by Frank Basile, P.E., of Entech Designs, LLC, Vane Brothers’ Elizabeth Anne Class tugboats are close cousins to the Basile-designed Patapsco Class tugboats, 15 of which were produced between 2004 and 2009.

Measuring 100 feet long and 34 feet wide, with a hull depth of 15 feet, the model bow Hudson is powered by two Caterpillar 3516 Tier 3 engines, each generating 2,100 horsepower at 1,600 rev/min. Two John Deere PowerTech 4045, 99 kW generators deliver service power to the boat, while a third John Deere 4045 teamed with an Allison transmission drives the chain-driven Intercon DD200 towing winch. The Elizabeth Anne also has Reintjes marine gears supplied by Karl Senner, LLC, Kenner, LA.

The Hudson features the latest in solid-state, Simrad electronics and handsomely appointed, mahogany upper and lower pilothouses, as well as spacious accommodations for up to seven crew members.

Meanwhile, the Double Skin 601 is configured and outfitted in a nearly identical fashion to the most recent 55,000 bbl Vane Brothers barges that were delivered in 2015 by Indiana-based Jeffboat Shipyard. Like them, the Double Skin 601 is equipped with an 8,600 BTU thermal fluid heating system, vapor control system and cargo tanks coated with International Interline 994 Epoxy Novolac. However, the Double Skin 601 has a raised forecastle bow design, which provides additional reserve buoyancy.

The DS-601 and its sister, the DS-602, are both fitted with two fixed boom pedestal cranes each, Model F1-65, with a 65-foot boom length supplied by Techcrane International, Covington, LA.

Primarily tasked with towing petroleum barges engaged in the North Atlantic coastwise trade, the Hudson has joined the Elizabeth Anne among more than 20 vessels that are part of Vane’s Delta Fleet, based in Philadelphia. The DS-601 is also a new Delta Fleet member.

NEW TUG FOR SEA VISTA
In early April, BAE Systems Southeast Shipyards, Mobile, AL, launched the first of two 12,000 hp ATB tugs for Sea-Vista ATB, LLC.

One of the interesting features of the tug M/V Sea Power is that it has two independently controlled and operated hydro-dynamic Van der Velden Barke rudders. Independent Proportional Steering will allow the rudders to be actuated either independently or synchronized. The rudders were supplied by Dutch company Van der Velden Marine Systems (VDVMS) in conjunction with its U.S. representative Ships Machinery International, Inc. (SMI).

Van der Velden says that tank tests showed that rudder design was extremely effective for this type of vessel. This ATB tug will have enhanced maneuverability and excellent course keeping stability. The efficiency provided by this high technology rudder solution will result in significant savings over the life of the vessel.

The 43m x 14m ATB tug, with a draft of 6.75m, is designed by Seattle-based Guido Perla and Associates, Inc. (GPA). The tug’s power is supplied by two 4,640 kW main engines and three 250 kW main generators, with a standby emergency generator of 150 kW. The vessel uses a pin connector system between the tug and the barge and fully complies with ABS Under 90 m Rules, Maltese Cross A1 AMS ACCU Towing Vessel, SOLAS, USCG Subchapter I.

“We are pleased that our client selected this state of the art rudder system for their new vessel,” said SMI Vice President Arthur Dewey, and “we are confident that their faith in Van der Velden rudders will be rewarded over the long haul.” Van der Velden reports that the Sea Power is the only vessel of its kind in the U.S. at present time.

The tug will have exceptional maneuverability, with two independently controlled and operated hydrodynamic Van der Velden Barke rudders. Independent Proportional Steering will allow the rudders to be actuated either independently or synchronized.

Van der Velden has done a lot of work to facilitate the installation of these rudders into a hull and worked closely with Guido Perla Associates Inc. and BAE Systems to assure a smooth transition from initial design to final installation.

GPAI Chairman Guido Perla commented, “Van der Velden provided excellent technical support and on time delivery of design documents that helped us develop the engineering and design for the installation of their steering system. Their coordination with our staff was prompt and to the point. We appreciated their support.”

Van der Velden says that the key driver behind the Barke rudder is its innovative and sophisticated progressive high lift design, offering unsurpassed maneuvering and course-keeping performance, as well as smooth operational comfort. The progressively operating flap linkage system is contained in a fully enclosed, grease-lubricated Barke housing. This results in minimum wear on the linkage components and eliminates the problems caused by contact with floating objects.  

Another set of Barke high-lift rudders will be installed on a second ATB tug before this summer.

BARGE FOR PROVPORT
Conrad Shipyard, Amelia, LA, recently delivered a 300-foot long x 72-foot wide rake/box barge with a deck rating of over 6,000 pounds per square foot to ProvPort, Providence, RI, according to naval architect JMS Naval Architects, Mystic, CT. The crane barge design allows for the easy loading and unloading of cargo from ships to the dock or from ship to ship.

JMS Naval Architects, Mystic, CT, engineered and designed the crane barge for the State of Rhode Island that will be used for stevedoring operations at ProvPort Inc.

ProvPort is a nonprofit public-private partnership, formed in 1994, which owns and operates the municipal port of the City of Providence, RI. ProvPort is New England’s premier deep-water multimodal facility for international trade and domestic distribution and one of the busiest ports in America’s northeast.

JMS designed the barge to carry and operate the facility’s 440-ton Liebherr LHM 550 mobile harbor cranes. The barge is ABS classed A1 with notation “Deck Barge,” uninspected and unmanned. JMS also created the technical specification documents to utilize for the solicitation of shipyard bids and provided owner’s representative services during the construction of the barge at Conrad Industries.

The contract was funded by the State of Rhode Island’s Transportation Investments Generating Economic Recovery (TIGER) II grant program award managed by the Rhode Island Commerce Corporation. The grant was created by Congress in the 2010 Transportation Appropriations Act and allowed the purchase and installation of the barge and two high performance harbor cranes. The new stevedoring equipment will modernize and enhance the port’s ability to continue its existing bulk material operations while expanding its capabilities to accommodate container operations; thus alleviating demand on the Port of Boston—the only existing container port in New England. The new crane barge will be critical for the port which has relied on 30-year-old rented crane barges that have been prone to breakdowns and have been out service for prolonged periods. The crane barges are estimated to remove on average 1,000 trucks per week off the northeast corridor highway system—one of the most congested in the country.

NEW HARBOR TUGS FOR BAYDELTA, MCALLISTER
Jensen Maritime, Seattle, is designing tractor tugs for both U.S. East Coast and West operators. One is for Vessel Chartering LLC, a wholly owned dividsion of BayDelta Navigation. The new tug is powered by a pair of 3,385-horsepower Caterpillar 3516 EPA Tier 4 engines and is the third tugboat designed by Jensen Maritime with engines meeting EPA Tier 4 requirement.

The tug was designed without ballast tanks, eliminating the need for ballast water discharge and therefore ballast water treatment systems. To maintain proper trim, the vessel will transfer fuel, as necessary.

The tug is being built by JT Marine Inc. shipyard in Vancouver, WA, for delivery in second quarter 2017.

Jointly developed by Vessel Chartering and Jensen, the 110-ft x 40 ft tug has the ship assist and escort capabilities of smaller harbor tugs, while delivering the improved towing performance and increased range of larger ocean-going tugs.

The design offers the flexibility to support ship escorts, assists and towing, with the escort capability being enhanced to provide support for assisting the large, 18,000 TEU containerships expected to make an increasing number of West Coast port calls.

With an electrically powered, double drum tow winch aft by Rapp USA and an electrically powered hawser winch forward by Markey Machinery as deck machinery, the vessel will be capable of a 93-to-95 short-ton bollard pull. Both winches’ electrical power will remove any chance of a hydraulic oil spill on deck.

The tug is designed to carry up to 123,000 gallons of fuel, 4,300 gallons of fresh water, and up to 4,500 gallons of urea, which is used in the main engine exhaust Selective Catalyst Reduction (SCR) treatment system used to meet EPA Tier 4 emissions requirements.

On the East Coast, McAllister Towing, New York, NY, has contracted with Horizon Shipbuilding, Inc., Bayou La Batre, AL, to build it two new 100 ft x 40 ft new escort tugs.

The tugs will be powered by 3516E EPA Tier 4-compliant Caterpillar engines with Schottel SRP4000FP propulsion units producing 6,770 hp and 80 metric tons bollard pull.

The tugs will be the 31st and 32nd tractors and the first Tier IV tugs in McAllister’s fleet.

They will be ABS classed Maltese Cross A-1 Towing, Escort Service, FiFi 1 and Maltese Cross AMS.

The hull has been designed by Jensen Maritime for enhanced ship docking abilities in addition to direct and indirect escorting and the tugs have been designed and simulator tested to assist new Post-Panamax and Ultra-Large Vessels.

Towing machinery will include a Markey asymmetric render-recover winch on the bow and a Markey tow winch with a spool capacity of 2,500 ft of 2¼ in wire on the stern.

MARCON BROKER FOR NEW DESIGN TUG
Purple Water Ltd. has appointed Marcon International, Inc., Coupeville, WA, as exclusive broker to handle the shipyard licensing for construction of an innovative new tug in the Americas.

Called the Giano tug, the compact double-ended tug has a high displacement tunnel hull form, two large structural keels and a straight-line controllable pitch thruster configuration designed and built solely for ship handing.

With intuitive in-line handling controls, the tug can produce 55 tonnes (70 tonnes) of bollard thrust and pull in all directions at full power with true 360 degree maneuverability, while maintaining a 0 degree list – plus a side-stepping speed of 7 knots – from full ahead to full speed sideways in 10 seconds.

The tug works equally well from the bow or stern and is fitted with 75 tonne escort winches fore and aft.

The design is claimed to has the highest stability numbers of any escort tug afloat, not only in its own 24 m compact class, but also compared with the 32 m escort terminal class.

Two separate engine rooms, a separate generator room and a double hull with integral “W” heavy duty fendering and patented underwater fenders provide a high level of safety, and allow the tug the unique capacity to side thrust and push at full power without listing, while assisting vessels in confined spaces

The Gianotug design is patented over 40 countries.

After four years of research and development, the first tug of this class, is now available in Italy for shipowners and shipyards interested in licensing and building the design to inspect and experience a “hands-on” demonstration of the tug’s capabilities.

Built by Chinese shipbuilder Guangdong Bonny Fair Heavy Industry, the 25.75 m x 13.02 m x 5.20 m depth / 5.30 m Giano is powered by twin 1,678 kW CAT 3512C-HD diesels developing a total power of 4,562 HP at 1,800 RPM.

A Schottel SRP-3000 azimuthing drive with a controllable pitch prop is mounted in a straight line at each end, with the tunnel hull specifically designed to eliminate propeller interference.

Topside access and ultra-short shaft lines allow for main engine removal in a few hours.

The U.K. flagged Giano is classed LR +100A1, Escort Tug, FiFi-1 (2,400 cu.m/h) with water spray, Unrestricted – MCA WB Area 1 (up to 150 miles from safe haven). While this first vessel has a 55 tonnes bollard pull, the unified design allows for both 55 tonnes and 70 tonnes bollard pull versions to be built.

Eastern delivers Z-Tech escort tug

JUNE 3, 2016 — Delivered by Eastern Shipbuilding Group, Panama City, FL  last month, the Zyana K is the second in a series of Robert Allan, Ltd. (RAL) designed Z-Tech 2400 class

Eastern launches 340 ft MPFSV for Harvey Gulf

MAY 24, 2016 — Eastern Shipbuilding Group, Inc., Panama City, FL, reports that its Allanton Shipyard last month launched Harvey Blue-Sea (Hull 250) the second of two 340 ft multi-purpose service vessels

  • Uncategorized

The Evolution of the Z-Drive Inland Towboat

 

Birth of the Z-drive
Z-drive propulsion is over 60 years old. The Rudder Propeller, or Z-drive as we know it today, was developed and built in 1950 by Josef Becker, founder of the present-day Schottel Group. But it wasn’t until the 1980’s that its use began in North America, when it was found predominately in ship assist tugs, not inland towboats. Since the early ‘80’s the Z-drive ship assist tug fleet in North America has grown from a handful to almost 300, tripling in the last 15 years. It continues to grow and is the dominant propulsion in newbuild ship assist tugs.

The inland towboat industry has lagged in adopting Z-drive technology, but is now on the precipice of the same exponential growth experienced in the ship assist market. In 2008, two inland companies utilized Z-drive towboats. One was Southern Towing Company out of Memphis, TN, and the other a Pacific Northwest company, Shaver Transportation. Less than a half-dozen Z-drive towboats worked the inland river system. Today, we find 10 companies and well over 50 Z-drive towboats built or under construction—and more to come. What caused the change in 8 years?

The inland towing industry is well-versed in navigating the challenging system of inland rivers and canals. It has expertise in adapting to a river’s changing depth, sand bars, currents, and back eddies, and has developed reliable routes and channels that they have followed for years. However, they also expect periodic dramatic changes—such as when a river cuts a new channel to bypass an established one that has silted in. The same is happening with propulsion technology in the industry. Z-drive technology is the cut bank that has broken through to a new and more efficient pathway towards getting the job done. Two companies were instrumental in carving this new path.

Pioneers
The growing popularity of Z-drives in the inland towing industry today is due in large part to two Z-drive pioneers of the distant and recent past—the towboat Miss Nari, and Southern Towing Company.

The Miss Nari, originally named the Delta Cities, was built as a twin-screw conventional towboat in 1951. The boat burned in 1970 and changed hands several times. Eddie Conrad renovated the newly named Miss Nari with Niigata z-drives and diesel engines, and returned it to service in 1982. It is widely accepted that the Miss Nari was the first U.S. towboat to use Z-drive propulsion on the Mississippi River system.

Bill Stegbauer of Southern Towing Company of Memphis, TN, is the more recent pioneer. In the spring of 2006, he began discussions with Ed Shearer of Shearer & Assoc., Inc., to design a new series of 3,200 hp towboats. Following research and discussion, Stegbauer decided to pursue the possibility of a towboat equipped with Z-drives. The first of eight Southern Towing Z-drive towboats went into service in August 2008.

Many factors that led Southern Towing to Z-drive towboats are the same ones driving the change today. However, Southern Towing was the first to step into the deep end of the pool while others stood on the edge, waiting to see whether the Z-drive concept would sink or swim. A key factor in getting others to follow was the empirical data generated by Southern Towing’s fleet, which had multiple opportunities to make side-by-side performance comparisons between conventional and Z-drive towboats pushing identical tows on identical routes.

Performance
Inland towboats are tasked with maneuvering large tows, running at 80% load 24/7 year round, navigating bends, currents and restricted channels, meeting other vessels in close quarters and transiting narrow bridges and locks. Key performance criteria for an inland towboat are its amount of thrust, steering power and maneuverability. Z-drive propulsion has inherent advantages over conventional propulsion in all of these categories. It has a high ratio of converting horsepower to thrust, 50% more backing (astern thrust) power, 50-70% more steering force and, of course, 360° thrust capability.

The advantageous Z-drive thrust and steering performance translate into more efficient and safer operations in most inland towing applications. A critical factor to a towboat’s maneuvering success is its ability to “hold the stern” or “not lose the stern.” That concept is extremely important to a towboat pilot. Whether he or she is going into a lock, making a bridge, or going around a bend, his or her fate rests largely on the ability to control the stern of the towboat, its location in the river, its aspect to the current, and its rate of swing and advance.

Making a bend while heading downstream is an everyday occurrence on the rivers. Flanking and driving a bend are two common techniques used to navigate a bend. Both maneuvers require the pilot to position the stern of the towboat so that the pilot can overcome the tendency of the current to sweep the tow down on the outside of the turn. In the case of driving the bend, the pilot has to have enough steering power to swing the tow and power out of the bend before the towboat ends up on the outside bank. In the case of flanking, the pilot holds the stern more or less stationary over the ground while the current pushes the head end of the tow around. Flanking requires long periods of time and large amounts of power to navigate through relatively short stretches of the river. This is less efficient and uses more fuel but is required if the towboat doesn’t have enough power and maneuverability to drive the bend. A Z-drive towboat with its superior omni-directional thrust may be able to drive the bend in cases where a conventionally propelled towboat would have to flank.

This is one example of Z-drive performance manifesting as operational efficiency in comparison to conventionally propelled towboats. A Z-drive more efficiently transfers main engine horsepower and applies that horsepower to inland towing applications. Put simply, it can do more with less. A Z-drive towboat consumes 20-30% less fuel, has shorter transit times, covers more distance per gallon and pushes a greater number of barges than a conventional towboat of similar horsepower.

Skepticism
The question remains: If Z-drives are so great what took so long? Skepticism to new technology is part of the DNA of the towing industry. And for good reason. The life cycle of a towboat can be 40 to 50 years, requires a large capital outlay and may not produce a return on investment for 5-10 years. You don’t want to make a bad bet that you must live with for 50 years. Questions of initial cost, reliability and maintenance have always been associated with the introduction of new technology, and Z-drives were no exception. What change agents overcame this skepticism? Although performance advantages of Z-drive propulsion are well documented, economic factors were the final push to get the inland towboat industry to accept Z-drive propulsion.

Economic Change Agents
There are five economic change agents:

  • Empirical Performance Data
  • Fleet Modernization
  • Z-drive Construction Cost Parity
  • Critical Mass
  • Competitive Standard

 Empirical Performance Data
The favorable empirical data generated by Southern Towing provided the “real” towboat data proving that the advantages of Z-drive propulsion are not just theoretical; they are a real.

Fleet Modernization
The inland fleet is in the midst of modernization. Much of the existing fleet is at or near the end of its life-cycle and needs to be replaced. Companies are faced with making large capital investments in equipment. Z-drive propulsion must be evaluated in constructing a towboat today that will remain competitive over the next 30 to 50 years.

Z-drive Construction Cost Parity
The difference in construction costs between conventional and Z-drive propelled towboats turns out to be negligible. It was once thought that Z-drives were more expensive to construct. This assumption was based on the price of Z-drive units. However, it has become apparent that the elimination of reduction gears, shafting, rudders and steering systems negate a large portion of the cost difference. There are also maintenance costs that are reduced or eliminated by removing some of the major mechanical components of a conventionally propelled towboat.

Critical Mass
The fact that there are now 50 or more Z-drive towboats in operation and under construction and more on the way has created a critical mass—whereas at one point a Z-drive towboat was a novelty, it is quickly becoming the norm.

The inland towing industry has gone through many major changes. Just two of them are the transition from steam to diesel and paddlewheel to propeller. These changes have increased efficiency, reduced fuel costs and made the industry safer. Clearly, the use of Z-drive propulsion is another such evolution. While it may not be appropriate for all inland towing applications, what was once a unique and rarely used technology is rapidly becoming an industry standard. Towboat companies positioning themselves for the future will be drawn to Z-drive propulsion. Like the rivers they transit every day, the path of the inland towing industry has cut a new channel.

  • Uncategorized

The Evolution of the Z-Drive Inland Towboat

 

Birth of the Z-drive
Z-drive propulsion is over 60 years old. The Rudder Propeller, or Z-drive as we know it today, was developed and built in 1950 by Josef Becker, founder of the present-day Schottel Group. But it wasn’t until the 1980’s that its use began in North America, when it was found predominately in ship assist tugs, not inland towboats. Since the early ‘80’s the Z-drive ship assist tug fleet in North America has grown from a handful to almost 300, tripling in the last 15 years. It continues to grow and is the dominant propulsion in newbuild ship assist tugs.

The inland towboat industry has lagged in adopting Z-drive technology, but is now on the precipice of the same exponential growth experienced in the ship assist market. In 2008, two inland companies utilized Z-drive towboats. One was Southern Towing Company out of Memphis, TN, and the other a Pacific Northwest company, Shaver Transportation. Less than a half-dozen Z-drive towboats worked the inland river system. Today, we find 10 companies and well over 50 Z-drive towboats built or under construction—and more to come. What caused the change in 8 years?

The inland towing industry is well-versed in navigating the challenging system of inland rivers and canals. It has expertise in adapting to a river’s changing depth, sand bars, currents, and back eddies, and has developed reliable routes and channels that they have followed for years. However, they also expect periodic dramatic changes—such as when a river cuts a new channel to bypass an established one that has silted in. The same is happening with propulsion technology in the industry. Z-drive technology is the cut bank that has broken through to a new and more efficient pathway towards getting the job done. Two companies were instrumental in carving this new path.

Pioneers
The growing popularity of Z-drives in the inland towing industry today is due in large part to two Z-drive pioneers of the distant and recent past—the towboat Miss Nari, and Southern Towing Company.

The Miss Nari, originally named the Delta Cities, was built as a twin-screw conventional towboat in 1951. The boat burned in 1970 and changed hands several times. Eddie Conrad renovated the newly named Miss Nari with Niigata z-drives and diesel engines, and returned it to service in 1982. It is widely accepted that the Miss Nari was the first U.S. towboat to use Z-drive propulsion on the Mississippi River system.

Bill Stegbauer of Southern Towing Company of Memphis, TN, is the more recent pioneer. In the spring of 2006, he began discussions with Ed Shearer of Shearer & Assoc., Inc., to design a new series of 3,200 hp towboats. Following research and discussion, Stegbauer decided to pursue the possibility of a towboat equipped with Z-drives. The first of eight Southern Towing Z-drive towboats went into service in August 2008.

Many factors that led Southern Towing to Z-drive towboats are the same ones driving the change today. However, Southern Towing was the first to step into the deep end of the pool while others stood on the edge, waiting to see whether the Z-drive concept would sink or swim. A key factor in getting others to follow was the empirical data generated by Southern Towing’s fleet, which had multiple opportunities to make side-by-side performance comparisons between conventional and Z-drive towboats pushing identical tows on identical routes.

Performance
Inland towboats are tasked with maneuvering large tows, running at 80% load 24/7 year round, navigating bends, currents and restricted channels, meeting other vessels in close quarters and transiting narrow bridges and locks. Key performance criteria for an inland towboat are its amount of thrust, steering power and maneuverability. Z-drive propulsion has inherent advantages over conventional propulsion in all of these categories. It has a high ratio of converting horsepower to thrust, 50% more backing (astern thrust) power, 50-70% more steering force and, of course, 360° thrust capability.

The advantageous Z-drive thrust and steering performance translate into more efficient and safer operations in most inland towing applications. A critical factor to a towboat’s maneuvering success is its ability to “hold the stern” or “not lose the stern.” That concept is extremely important to a towboat pilot. Whether he or she is going into a lock, making a bridge, or going around a bend, his or her fate rests largely on the ability to control the stern of the towboat, its location in the river, its aspect to the current, and its rate of swing and advance.

Making a bend while heading downstream is an everyday occurrence on the rivers. Flanking and driving a bend are two common techniques used to navigate a bend. Both maneuvers require the pilot to position the stern of the towboat so that the pilot can overcome the tendency of the current to sweep the tow down on the outside of the turn. In the case of driving the bend, the pilot has to have enough steering power to swing the tow and power out of the bend before the towboat ends up on the outside bank. In the case of flanking, the pilot holds the stern more or less stationary over the ground while the current pushes the head end of the tow around. Flanking requires long periods of time and large amounts of power to navigate through relatively short stretches of the river. This is less efficient and uses more fuel but is required if the towboat doesn’t have enough power and maneuverability to drive the bend. A Z-drive towboat with its superior omni-directional thrust may be able to drive the bend in cases where a conventionally propelled towboat would have to flank.

This is one example of Z-drive performance manifesting as operational efficiency in comparison to conventionally propelled towboats. A Z-drive more efficiently transfers main engine horsepower and applies that horsepower to inland towing applications. Put simply, it can do more with less. A Z-drive towboat consumes 20-30% less fuel, has shorter transit times, covers more distance per gallon and pushes a greater number of barges than a conventional towboat of similar horsepower.

Skepticism
The question remains: If Z-drives are so great what took so long? Skepticism to new technology is part of the DNA of the towing industry. And for good reason. The life cycle of a towboat can be 40 to 50 years, requires a large capital outlay and may not produce a return on investment for 5-10 years. You don’t want to make a bad bet that you must live with for 50 years. Questions of initial cost, reliability and maintenance have always been associated with the introduction of new technology, and Z-drives were no exception. What change agents overcame this skepticism? Although performance advantages of Z-drive propulsion are well documented, economic factors were the final push to get the inland towboat industry to accept Z-drive propulsion.

Economic Change Agents
There are five economic change agents:

  • Empirical Performance Data
  • Fleet Modernization
  • Z-drive Construction Cost Parity
  • Critical Mass
  • Competitive Standard

 Empirical Performance Data
The favorable empirical data generated by Southern Towing provided the “real” towboat data proving that the advantages of Z-drive propulsion are not just theoretical; they are a real.

Fleet Modernization
The inland fleet is in the midst of modernization. Much of the existing fleet is at or near the end of its life-cycle and needs to be replaced. Companies are faced with making large capital investments in equipment. Z-drive propulsion must be evaluated in constructing a towboat today that will remain competitive over the next 30 to 50 years.

Z-drive Construction Cost Parity
The difference in construction costs between conventional and Z-drive propelled towboats turns out to be negligible. It was once thought that Z-drives were more expensive to construct. This assumption was based on the price of Z-drive units. However, it has become apparent that the elimination of reduction gears, shafting, rudders and steering systems negate a large portion of the cost difference. There are also maintenance costs that are reduced or eliminated by removing some of the major mechanical components of a conventionally propelled towboat.

Critical Mass
The fact that there are now 50 or more Z-drive towboats in operation and under construction and more on the way has created a critical mass—whereas at one point a Z-drive towboat was a novelty, it is quickly becoming the norm.

The inland towing industry has gone through many major changes. Just two of them are the transition from steam to diesel and paddlewheel to propeller. These changes have increased efficiency, reduced fuel costs and made the industry safer. Clearly, the use of Z-drive propulsion is another such evolution. While it may not be appropriate for all inland towing applications, what was once a unique and rarely used technology is rapidly becoming an industry standard. Towboat companies positioning themselves for the future will be drawn to Z-drive propulsion. Like the rivers they transit every day, the path of the inland towing industry has cut a new channel.