Rotortug infield support vessel will operate in Timor Sea

APRIL 18, 2017 — Construction of a Robert Allan Ltd. (RAL) designed ART 100-46 class infield support vessel (ISV) is well underway at Damen Shipyards Sharjah, UAE for KT Maritime Services Australia Pty Ltd. The company (a joint venture of KOTUG International B.V. and Teekay Shipping Australia Pty Ltd) commissioned the vessel after being awarded a contract with Conoco Phillips to support its offshore operations in the Timor Sea.


The ART 100-46 is a custom-designed Rotortug measuring 46 m in length with a bollard pull of 100 tonnes. Designed by Robert Allan Ltd. in close collaboration with KT Maritime and Rotortug B.V., it will be powered by the patented Rotortug technology featuring three separate azimuthing propulsion units (two forward, one aft). Because of the Rotortug propulsion configuration, dynamic positioning capability was easily achieved by the addition of only a single tunnel thruster in the stern of the vessel.

Designed to meet the demanding support requirements of offshore oil and gas facilities. The vessel is capable of wide variety of missions including:

• Escorting, berthing and unberthing operations (working off either the bow or the stern)
• Tanker pull-back operations
• Anchor handling
• Floating hose handling operations and hose maintenance operations
• Subsea support activities
• Fi-Fi Class 1 capability
• Pilot transfer
• Security activities
• Rescue and emergency evacuation capability

The aft deck features a waterfall winch with both steel wire and synthetic ship-handling towline, a retractable 800 mm diameter towing staple, Kooiman Delta Pins and fork, a stern roller, two tugger winches, two capstans, and a deck crane. The fore deck features a split drum ship-handling and tanker pull-back winch.

The vessel is designed to be able to operate in fairly significant environmental conditions. The RAL RAstar style hull form was selected due to its proven seakeeping performance in high sea states. The RAstar hull form provides significant reductions in motions and accelerations compared to more standard wall-sided hull forms.

The hull and appendage configuration was refined during a model test program conducted at the Vienna Model Basin with support from RAL’s Computational Fluid Dynamics (CFD) team to determine the optimal appendage configuration balancing the competing attributes of course stability, maneuverability, side stepping speed, and resistance.