The 98'6"x43'x17'6" Spartan, the latest high-power tug to join the Seabulk fleet, adds to a growing list of vessels featuring the fully integrated hybrid propulsion plant from Berg Propulsion.

Already operational at Port Arthur, Texas, following delivery by Master Boat Builders, the Robert Allan-designed RApport 3000 vessel, which has an 18'6" draft, is the first of two 90-ton bollard pull tugs using this latest Berg package, with the second due in service in the third quarter.

In addition to Berg MTA 628 azimuthing thrusters, Berg VS3 variable frequency drives with motors, and its own hybrid control system, Berg’s design, supply, and integration includes the switchboard with full power management plus control of the tug’s twin Caterpillar 3512E EPA Tier 4 (2,550 hp) main engines and its gensets — two Cat C18s and one C7.1. The propulsion package gives the Spartan a running speed of 12.6 knots.

Berg’s hybrid electric propulsion system includes high levels of redundancy for safety as well as the ability to switch seamlessly between operating modes with the push of a button. A vessel can run on main engines only, gensets only, or a combination of the two, optimizing energy use across the entire operating profile.

A tug in transit can minimize energy consumption and eliminate main engine wear by running on a single generator set. In hybrid mode, power is balanced between the diesel engines and electrical motors to optimize fuel consumption, maneuvering response, and bollard performance.

“During the first weeks in operation, Spartan has been living up to the promises made for hybrid propulsion vessels,” Daniel Thorogood, President and CEO, Seabulk, said in a prepared statement. “Seabulk’s commitment to improving the sustainability of its operations is represented by its investment in a new generation of vessels whose flexibility is proving that hybrid tug technology is our choice for the future.”

On deck is a Jonrie Intertech hawser winch, series 225, with a line pull of 25 tons at 100 fpm, 300 ton brake capacity, and 600’z of 8" Saturn 12 HMPE rope. There are also two Viking 10-man life rafts.

The solution, whose installation was managed at the yard by Berg’s distributor and partner in the area, Thompson Marine, is the most advanced hybrid electric package ever delivered by Berg Propulsion.

“Thompson Marine managed the details from the earliest design phase through sea trials together with Master Boat Builders, Seabulk, Berg Propulsion, and Caterpillar” said Richard Tremayne, marine business manager, Thompson Marine. “This delivery sets down a marker that — with the right team in place — the sustainability and performance benefits of advanced hybrid electric propulsion are available to all.”

Spartan is ABS classed, Maltese Cross A1, Towing Service, Escort Vessel, AMS, UWILD.

Tankage includes 47,679 gals. fuel; 5,087 gals. fresh water; 243 gals. main engine lube oil; and 236 gals. gear oil.

“This has been a landmark delivery for Master Boat Builders in next generation tug construction, and a testament to the value of teamwork,” said Garrett Rice, president, Master Boat Builders. “The approach was collaborative throughout the design, engineering, and building phases, and we look forward to completing work on the second of these innovative Seabulk tugboats later this year.”


Ken Hocke has been the senior editor of WorkBoat since 1999. He was the associate editor of WorkBoat from 1997 to 1999. Prior to that, he was the editor of the Daily Shipping Guide, a transportation daily in New Orleans. He has written for other publications including The Times-Picayune. He graduated from Louisiana State University with an arts and sciences degree, with a concentration in English, in 1978.