An offshore support vessel designed to tow and position mobile drilling rigs and handle anchors in deepwater operations.
In practice
Anchor handling is one of the most hazardous operations in the offshore industry, with significant risk from snap-back of tensioned wires, sliding anchors on deck, and capsize from sudden load shifts in heavy weather. Industry guidelines such as those published by the Oil Companies International Marine Forum and Oil and Gas UK provide risk assessment frameworks for anchor handling operations. Engineers on AHTS vessels maintain the towing winch, anchor handling winch, DP thrusters, and firefighting systems to class notation standards, and the vessels carry enhanced firefighting and rescue equipment for emergency response duties at offshore installations.
Regulatory detail & full definition
Anchor handling tug supply vessels are powerful offshore support vessels designed specifically to tow mobile offshore drilling units to and between locations, deploy and recover mooring anchors in deepwater, and supply deck cargo, fuel, water, and drilling mud to offshore installations. They typically range from around 3,000 to 10,000 brake horsepower on smaller units to over 25,000 brake horsepower on large deepwater units, with enormous open stern decks, towing winches, anchor handling winches, and shark jaws for controlled deck-level anchor chain management. Dynamic positioning Class 2 systems are fitted on modern AHTS vessels for precision anchor deployment in deepwater fields.
Anchor handling is one of the most hazardous operations in the offshore industry, with significant risk from snap-back of tensioned wires, sliding anchors on deck, and capsize from sudden load shifts in heavy weather. Industry guidelines such as those published by the Oil Companies International Marine Forum and Oil and Gas UK provide risk assessment frameworks for anchor handling operations. Engineers on AHTS vessels maintain the towing winch, anchor handling winch, DP thrusters, and firefighting systems to class notation standards, and the vessels carry enhanced firefighting and rescue equipment for emergency response duties at offshore installations.