Eastern Shipbuilding Introduces New Inland Towboat

Eastern Shipbuilding Group has introduced its vision of the future for inland waterways with its 120 foot, 4,200 horsepower Inland Towboat design named the Thunderbolt. The Thunderbolt combines twin electric V-pod propulsion and diesel-electric technology offering it to the U.S. inland waterway’s market providing increased efficiency, performance, maneuverability, crew comfort and capacity.

The idea for the Thunderbolt came from across the aisle conversations at the 2013 International WorkBoat Show in New Orleans, LA. On the rivers, Thruster Propulsion Systems are starting to get noticed and are out performing conventional nozzle propeller propulsion systems with main/flanking rudder steering. 

Eastern Shipbuilding Group and Verhaar Omega began discussions and realized they were driving towards a more refined towboat thruster propulsion system design. Eastern has delivered 19 diesel-electric offshore supply vessels starting in 2010 and 74 inland towing vessels since 2007. 

The Thunderbolt design joins Eastern’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.

For more than a year Eastern Shipbuilding has worked with Gilbert Associates developing its new fresh hybrid Thunderbolt diesel electric design. The Thunderbolt has been designed using ABS class rules for building and classing steel vessels for service on rivers and intracoastal waterways (2014). It is also designed to the proposed U.S. Coast Guard 46CFR (Sub-Chapter M) towing vessel rules and IEEE 45 2002 standards.

The Thunderbolt is a 120ft inland river class towboat with 690VAC diesel-electric and twin azimuthing Verhaar Omega electric V-pod propulsion units. Cummins Mid-South 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, 1,400HP @ 1,800RPM marine diesel engine. These three engines provide optimal fuel consumption with 4,200 total installed horsepower. Each engine also powers a Cummins AVK DSG-74 water-cooled generator, which can supply at 990kW, 690 VAC at 1,800 RPM. This system performs seamlessly with the Power Management System (PMS), provided by Beier Radio to optimize fuel consumption with superb efficiency without sacrificing power and performance. 

The IEM Marine 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 offer less vibration and noise along with power management and automation all result in lower operating costs, system redundancy, increased safety, increased crew comfort and less crew fatigue.

With these systems in place, the fuel consumption on the Thunderbolt verses traditional inland towboats is dramatic. The 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. 

In addition for superior maneuverability and precision, the twins V-pods have VFD-reversing induction motors each at 1,320kW (1,770 HP). The V-pods are installed from the top, avoiding emergency dry-docking if a unit is damaged. Sewart Supply has been the U.S. representative for Verhaar Omega for over ten years, providing sales, parts and repair services.