Shipbuilding: Inland Towing Thunderstruck

Eastern Shipbuilding offers the 4,200 hp Thunderbolt inland towboat designed around twin azimuthing Verhaar Omega electric V-Pod propulsion and diesel-electric technology. The ESG approach was collaborative, with input from operators, naval architects (Gilbert Associates, Inc. (GAI)) and propulsion OEM’s (Verhaar Omega: since 2012, 19 Omega V-pods have been installed and are in service in Europe on various types of vessels). Thunderbolt will be built to ABS rules, but will not be classed. “Regulatory (ABS) Class Rules/Electrical IEEE-45 Standards/USCG Regulations are what is used to design and build vessels regardless of whether it is an Inland or Offshore vessel, requiring  class or not,” said Steve Berthold, VP, Eastern Shipbuilding, in a recent interview with MR sister-publication MarineNews.

In selecting the podded propulsion system for inclusion on the design, Eastern came upon Verhaar Omega after meeting with two inland owner/operators that currently have Z-drive towboats, and others that didn’t. Listening to each and noting their concerns, it was decided that the V-Pod was the best solution. Because the Thunderbolt will typically operate in shallow, sometimes turbid, debris filled water, ESG designed underwater protection in the form of a pipe guard protection system for each Omega V-Pod. These pipe guards protect the V-Pod allowing the vessel to ride over shallow water mud flats, protect the vessel from side bank impacts when turning in rivers and canals and stern impact protection when backing down.

Omega itself offers a propeller guard which is bolted directly to the nozzle which protects the propeller from debris entering and being lodged between the blade tip and the nozzle. The Omega V-Pod propulsion electric motor also has a shutdown sensor with alarm and is reversible, allowing the operator to reverse propeller rotation enabling nozzle/propeller jammed debris to be dislodged.

The Omega V-Pod is designed with reduced maintenance in mind. The V-Pods are enclosed in the aft main deck superstructure, with no drive shafts, couplings, drive gears, hydraulic systems or external piping systems. With the Thunderbolt mounting flange situated above the design waterline, dry-docking is not required for maintenance.

Thunderbolt was designed for the medium horsepower inland towboat fleet with twin 2 x 1,770HP (1,320kW) propulsion units and still be capable to operate in the ICW and canals at a design operating draft of 9.5 ft.. Currently, Omega has V-Pod units ranging from 445HP (330kW) to 2011HP (1,500kW), but the thrust efficiencies underway and the maneuvering capabilities are far greater than conventional tail shaft, propeller and nozzle propulsion systems. Comparing them to Z-drives the V-Pod efficiencies are most realized in reduced fuel consumption and higher thrust efficiencies.
 

(As published in the November 2015 edition of Maritime Reporter & Engineering News - http://magazines.marinelink.com/Magazines/MaritimeReporter)