Eastern Shipbuilding introduces z-drive inland towboat design
Eastern Shipbuilding Group Inc. (ESG) announced on Feb. 12 its vision of the future for inland waterways with a 120-foot, 4,200-hp inland towboat design, Thunderbolt. The new towboat combines twin electric V-pod propulsion and diesel-electric technology.
According to ESG, the idea for Thunderbolt came out of discussions at the 2013 International WorkBoat Show in New Orleans. On the rivers, thruster propulsion systems are starting to get noticed and are outperforming conventional nozzle propeller propulsion systems with main/flanking rudder steering. ESG and Verhaar Omega BV (Holland) began discussions and realized they were driving towards a more refined towboat thruster propulsion system design. ESG has delivered 19 diesel-electric offshore supply vessels starting in 2010 and 74 inland towing vessels since 2007. The new design joins ESG’s long history of building reliable vessels and is now integrating their proven “Tiger Shark Class” diesel-electric technology into a refined, environmentally friendly, highly maneuverable inland towboat design.
ESG worked with Gilbert Associates Inc. in developing its new fresh hybrid Thunderbolt diesel-electric design. Thunderbolt has been designed using ABS Class Rules for Building and Classing Steel Vessels for Service on Rivers and Intracoastal Waterways-2014. It is designed to the proposed U.S. Coast Guard 46CFR (Sub-Chapter M) Towing Vessel Rules and IEEE 45 2002 Standards.
The vessel is a 120-foot inland river class towboat with 690VAC diesel-electric and twin azimuthing Verhaar Omega electric V-Pod propulsion units. Cummins Mid-South LLC is providing the generator package with three identical diesel-electric power plants, Cummins QSK38-DM. Each engine is rated EPA Tier 3, V-12 cylinder, 38 liter, 1,400 hp at 1,800 RPM marine diesel engine. These three engines provide optimal fuel consumption with 4,200 total installed horsepower. Each engine powers a Cummins AVK DSG-74 water-cooled generator, which can supply at 990 kW, 690 VAC at 1,800 RPM. This system performs seamlessly with the Power Management System (PMS), provided by Beier Radio LLC to optimize fuel consumption with superb efficiency without sacrificing power and performance. The IEM Marine Inc. switchboard automatically starts and closes the appropriate main bus generator breakers with load-sharing controllers. The pilot is free to utilize the automated power management systems as much or as little as the pilot determines, allowing the pilot full control of the entire power management system at all times. The enhanced performance of V-Pod propulsion diesel-electric with constant speed generator engines offers less vibration and noise along with power management and automation, all resulting in lower operating costs, system redundancy, increased safety, increased crew comfort and less crew fatigue.
With these systems in place, the fuel consumption on Thunderbolt versus traditional inland towboats is dramatic. Thunderbolt is equipped with twin Verhaar Omega 690VAC electric V-Pod units and twin Omega Propulsion AFE/VFD drives. The twin independent Verhaar Omega V-Pods have 360-degree rotation and can rotate 180 degrees in approximately 14 seconds. For superior maneuverability and precision, the twins V-Pods have VFD-Reversing Induction Motors each at 1,320 kW (1,770 hp). The V-Pods are installed from the top, avoiding emergency dry-docking if a unit is damaged.
Shearer and Conrad collaborate on LNG towboat design
Conrad Shipyard LLC of Morgan City, La., and The Shearer Group Inc. (TSGI) of Seabrook, Texas, are working together to develop the design of a liquefied natural gas-powered 4,200-hp towboat utilizing a proven TSGI design. The team has been awarded an approval in principle by American Bureau of Shipping (ABS) for the design.
The towboat is based on TSGI’s proven azimuth drive (z-drive) towboat design that debuted in 2008. Eight of these towboats, which pioneered the use of z-drives for brownwater operations, have been built for Southern Towing Co., where significant fuel savings relative to conventional towboats have been well documented. Beyond this, the LNG-powered towboat design capitalizes on Wartsila’s proven dual-fuel technology but is not necessarily wedded to it. This technology is the most widely accepted dual-fuel technology in use in the domestic U.S. market. While Wartsila’s dual-fuel engines are medium-speed diesels, it is anticipated that future engine developments will result in lighter and smaller high-speed units. The design is flexible enough to allow for the use of either engine option as determined by the operator.
The Wartsila system specified is a smaller version of the system currently installed on the Harvey Gulf multipurpose supply vessels.
Diesel electric applications are perfect for LNG adoption because they allow the prime movers to run at constant speed.
“With Approval in Principle in hand, we know that the basic design is acceptable to ABS,” said Ed Shearer, TSGI’s principal naval architect. “Further, we know that ABS and USCG work hand in hand on many of these projects, and thus we infer that the major design issues are also acceptable to USCG. That said, the next step is to submit class drawings to ABS and USCG for review and approval. We expect that USCG will limit their review to the LNG storage and supply systems, as well as fire and safety plans.”
Hornbeck sells OSVs to U.S. Navy
Hornbeck Offshore Services (HOS) announced March 2 that three vessels were sold for cash consideration of $114 million. This is expected to result in a gain on sale of company assets of approximately $33 million.
HOS Arrowhead, HOS Eagleview and HOS Westwind have been supporting the Navy's submarine fleet on the East and West coasts since they were constructed in 2008 and 2009. In order for the Navy to continue receiving the capabilities of these vessels, Congress required their purchase from the Brooklyn-based offshore transport services provider.
The proceeds from this transaction will be used for general corporate purposes that may include retirement of debt, funding for the acquisition, construction or retrofit of vessels or discretionary share repurchases, the company said in a statement. The vessel purchase agreement includes an option for the acquisition of a fourth vessel currently under charter to the U.S. Navy, HOS Black Powder, that, if exercised as anticipated, would bring the aggregate sale amount to $152 million, which is expected to result in an aggregate gain on sale of assets for the four vessels of approximately $44 million.
In addition to these vessel sales, the company separately entered into an operations and maintenance (O&M) contract for the three vessels sold, which contains an initial term and annual renewal options spanning a 10-year operating period including annual dayrate escalations. Associated with the O&M contract, the company was awarded a time charter for HOS Black Powder that will remain in effect until the closing of the anticipated sale of the vessel pursuant to the U.S. Navy purchase option is completed. Hornbeck expects to complete the sale of HOS Black Powder by the end of the third quarter of 2015, subject to government funding.
Canada’s Davie lays keel for MV Armand-Imbeau II
Davie Shipbuilding of Lauzon, Quebec, announced in late February that the two ferries for the Tadoussac‒Baie-Sainte-Catherine route are to be built at a total cost of $125 million for year-round navigation on the Saguenay Fjord. The first ferry, MV Armand-Imbeau II, is scheduled for delivery in fall 2015, followed by the second, MV Jos-Deschênes II, four months later.
According to the builder, the ferries feature the latest generation in motorized systems, most notably liquefied natural gas (LNG) engines, and each ship uses electric thrusters instead of a conventional propulsion system. Measuring 301 feet overall, each ship will include eight rows on two decks, enabling the transport of up to 440 passengers and 110 vehicles, including tractor-trailers.
“Ferry construction is and has always been core business for Davie,” said Alan Bowen, Davie’s chief executive officer. “The STQ ferries incorporate many of the technologies in which we specialize, for example LNG propulsion, electrical thruster systems and high ice-class hulls.”
The keel laying ceremony took place at Chantier Davie in the presence of the Minister for Transport and the Implementation of the Maritime Strategy, Jean D’Amour, and the Chairman and Chief Executive Officer of the Société des traversiers du Québec, Jocelyn Fortier.
The construction of two ships for the Tadoussac crossing, the STQ continues the process of renewing its fleet, using an efficient green technology, which will allow users to broaden their experience on board its ferries. They will be the first LNG-propelled ferries built in North America.