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Tug Technology & Business

Tug Technology & Business

Seabulk deploys first US-built Rotortug

Mon 08 May 2017 by Martyn Wingrove

Seabulk deploys first US-built Rotortug
Trident's Z-drive configuration gives it good manoeuvrability and control in ports

Trident is the first Rotortug to be built in North America, demonstrating that US owners are willing to invest in advanced towing vessels

Seabulk Towing has deployed the first of three advanced Rotortugs, designed by Robert Allan and built by Master Boat Builders in Alabama, USA. They feature the unique triple Z-drive configuration, originally conceived and developed by the Netherlands-based Rotortug.

These three tugs will have an average bollard pull of 78 tonnes and free running speed of 12.5 knots, as achieved by Trident during sea trials. Seabulk Towing is a subsidiary of Seacor Holdings. Its executive chairman Charles Fabrikant exclusively told Tug Technology & Business that the Rotortug thruster configuration enhances the tugs’ manoeuvrability and control. He added that they raise the bar for ship-handling operations in US waters.

Mr Fabrikant said investment in these tugs demonstrated that US tugboat operators were using the latest tug designs from companies such as Robert Allan and advanced propulsion systems. His comments were in reaction to comments in the first quarter issue of Tug Technology & Business by Svitzer Americas regional managing director Martin Helweg, which suggested that US regulations were holding back investment in the latest tug designs. Mr Fabrikant commented that US owners were investing in tug technology when it was necessary and cost-effective, such as Seacor’s investment in the Rotortug series.

Trident will be followed by sister vessel Triton and one other this year. These are ART 80-98US-design tugs for harbour and terminal operations. Robert Allan said the design offers “exceptional omni-directional manoeuvrability and control, with a redundant propulsion machinery configuration”. The designer added: “The ART series offers enhanced performance for ship-handling, terminal support and escort towing.”

Seabulk’s Trident is 30m long and around 13m wide with a maximum draught of about 5.5m. It has capacity for 196m3 of fuel oil and 19m3 of potable water. The main propulsion incorporates three Caterpillar 3512C diesel engines, each rated 1,911 bhp at 1,600 rpm. These each drive a Schottel SRP 1012 fixed pitch Z-drive unit, two drives forward and one drive aft to form a triangle configuration. Twin 150kW Caterpillar generator sets provide the electrical power.

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 with Samson rope. Alphatron Marine supplied an AlphaBridge system including radar, propulsion controls and other electronics in the wheelhouse.


Trident particulars

  • Owner: Seabulk Towing
  • Design: ART 80-98US
  • Length oa: 30m
  • Breadth, moulded: 13m
  • Depth, moulded: 4.5m
  • Maximum draught: 5.5m
  • Bollard pull: 78 tonnes
  • Main engine: 3x Caterpillar 3512C, 1,911 bhp at 1,600 rpm
  • Propulsion: 3x Schottel SRP 1012 fixed pitch Z-drives
  • Classification: ABS
  • Construction yard: Master Boat Builders


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