ART Trident – The First US Built Rotortug®

February 8, 2017

The first US-built Rotortug®ART Trident has undergone trials and is now in service. Designed by Robert Allan Ltd., and designated as an ART 80-98US, she was built by Master Boat Builders in Bayou La Batre, Alabama, and is the first in a series of three being constructed for Seabulk Towing of Ft. Lauderdale, Florida. These tugs will truly raise the bar for ship-handling operations in US waters.

The ART (Advanced Rotortug®) designation applies to Robert Allan Ltd. designed tugs featuring the unique triple Z-drive configuration, originally conceived and developed by Rotortug® (KST) B.V. of the Netherlands. Offering exceptional omni-directional manoeuvrability and control, with a redundant propulsion machinery configuration, the ART series offers enhanced performance for ship-handling, terminal support and escort towing.

Particulars of the ART 80-98 US Class tug are as follows:

  • Length overall: 98’-6”
  • Beam, moulded, extreme: 43’-6”
  • Depth, moulded (hull): 15’-7”
  • Maximum draft: 18’-9”

Tank capacities at 100% are as follows:

  • Fuel Oil: 52,000 US gal
  • Potable Water: 5,000 US gal
  • Foam: 4,200 US gal

On trials, Trident met or exceeded all performance expectations, with the following results:

  • Average Bollard Pull, ahead: 78 tons
  • Free running speed, ahead: 12.5 knots

The vessel has been arranged and outfitted to a high standard with six (6) crew berths in total. The Master’s and Chief Engineer’s cabins are located in the deckhouse with two double crew cabins located on the lower accommodation deck. A fully appointed mess/lounge and a modern, fully equipped galley are also located in the deckhouse.

The deck machinery consists of a Jonrie Series 230 ship-assist hawser winch forward, and a Jonrie Series 500 combination towing/hawser winch on the aft deck. The tug is equipped to perform escort operations over both the bow and stern, and is also equipped for long line towing over the stern. The wheelhouse is designed for maximum all-round visibility with a forward control station providing maximum visibility to both fore and aft deck working areas and featuring an Alphatron Integrated Bridge System.

Main propulsion comprises three Caterpillar 3512C diesel engines, each rated 1,911 bhp at 1,600 rpm, and each driving a Schottel SRP 1012 fixed pitch Z-drive unit.

The electrical plant consists of two (2) identical diesel gen-sets, each with a power output of 150 ekW.

Ship-handling fenders at the bow consist of a row of cylindrical fender at the main deck level, 800 x 400 and a row of 480 x 300 “W” block fender arranged below. Two rows of 10” x 10” hollow “D” fender provides protection at the main and foc’sle deck sheer lines, and a 800 x 400 cylindrical fender is used at the stern with a course of 480 x 300 “W” block fenders beneath. A combination of 10” x 10” and 12” x 12” hollow “D” fenders are arranged around the stern and below the waterline for submarine operations.

For more information on the Trident or any of the ART series of tugs, or on any other high-performance vessel designs developed by Robert Allan Ltd., please contact us at

General Arrangement

A great video by Rick Groen: