Marine Link
Thursday, August 5, 2021

Eastern Debuts ‘Thunderbolt’ Towboat

Maritime Activity Reports, Inc.

February 13, 2015

Eastern Shipbuilding Group, Inc. introduced its new 120-foot, 4,200-horsepower Inland Towboat design, THUNDERBOLT, combining twin electric V-Pod propulsion and diesel-electric technology for what the builder calls its “vision of the future for the U.S. inland waterways.”


Eastern said the idea for the THUNDERBOLT came from across the aisle conversations 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. Eastern Shipbuilding Group, Inc. and Verhaar Omega, B.V. 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 history of building reliable vessels and is now integrating its Tiger Shark Class diesel-electric technology into a refined, environmentally friendly, highly maneuverable Inland Towboat design, the shipbuilder said.


For more than a year Eastern Shipbuilding has worked with Gilbert Associates, Inc. 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 120’ 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, 1,400HP at 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, 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 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, Eastern explained. 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, Inc. has been the U.S. Representative for Verhaar Omega for over 10 years, providing sales, parts and repair services. 


Twin V-Pod Thrust & Fuel Consumption Calculations which includes Ships Services:

40% V-Pod Thrust: 37,740# at 92 USG/hr. (2,208 USG/day)

78% V-Pod Thrust: 73,593# at 164 USG/hr. (3,936 USG/day)

100% V-Pod Thrust: 94,350# at 194 USG/hr. (4,656 USG/day)


Tank Capacities at 100%:

(Quantities are approximate)

Total Fuel Oil: 40,326 USG. (152.6m³) Freshwater/Ballast: 38,016 USG. (143.9m³)

Potable Water: 10,916 USG. (41.3m³)


Design Details:

Length (Molded): 120’-0” (36.57m) 

Beam (Molded) : 36’-0” (10.97m)

Hull Depth Amidships (Molded): 11’-3” (3.42m) 

Hull Depth Head Log (Molded): 13’-3” (4.03m) 

Hull Depth Stern Log (Molded): 12’-9” (3.88m) 

Design Waterline (DWL) : 9’-6” (2.98m)

Pilothouse Eye Level above (DWL): 34’-3” (10.43m) 

Berths: 10


Machinery Alarm and Power Management System:

Alarm/Power Management:  One Beier Radio- USCG Compliant, ABS Type Approved Programmable Logic Controllers (PLC) will be manufactured with a Siemens Based Electrical, Machinery Room Alarm & Monitoring System and integrated with the Power Management System with Remote 12” Monitoring fully operational in the Pilothouse and Engine Control Room.


Machinery, Electrical and Propulsion Delivery Systems:

Main Generator Engines: Three Cummins Mid-South- QSK38-DM, EPA Tier 3, V-12 Cylinder, 38 Liter, 1,400HP at 1,800RPM Marine Diesel Engines, Air Start and Keel Cooled.

Main Generators: Three Cummins Mid-South- AVK DSG74 Generators,60 Hz, 3 PHz 690VAC, 990kW at 1,800RPM (2.97MW) Continuous Rating at .80PF., IP 44 TEWAC, Keel Cooled.

Harbor Generator: One Cummins Mid-South- CMSL-QSB7DM, EPA Tier 3, Inline 6 Cylinder, 6.7 Liter, Marine Diesel Genset, 60Hz, 3 PHz, 480VAC, 90kW at 1,800RPM, Electric Start and Air Cooled.

Propulsion Units: Two Verhaar Omega (Sewart Supply, Inc.) Model C850, 690V Electric Azimuthing V-Pods, VFD-Reversing Induction Motor at 1,770HP/1,320kW (2.64MW) Internally Water Cooled. V-Pod Installation from above (top).

Propulsion Thrust (100%): 47,175 lbs. (210kn) x 2 = 94,350 lbs. at 5.2 mph.

Propellers: Two Verhaar Omega (5)-blade 86.6” (2,200mm) Diameter Fixed Pitch Propellers each with Rope Cutters.

Nozzles : Two Verhaar Omega Nozzles.

Maritime Reporter E-News subscription

Maritime Reporter E-News is the maritime industry's largest circulation and most authoritative ENews Service, delivered to your Email five times per week

Subscribe for Maritime Reporter E-News