VESSEL REVIEW | Shackleford – Versatile offshore catamaran for US East Coast survey specialist

Geodynamics, a North Carolina-based subsea survey company under Florida-based NV5, has taken delivery of a research and hydrographic survey vessel that will service customers in offshore wind market as well as undertake various other scientific survey missions.

Shackleford is a 73- by 26.7-foot (22.2- by 8.1-metre), semi-displacement aluminium catamaran vessel that was developed by Nic de Waal of Teknicraft Design in Auckland, New Zealand. This vessel will aid in fulfilling Geodynamics' objective of providing turnkey/"single pass" offshore surveys. It has therefore been specifically customised to serve the offshore wind sector on the US Eastern Seaboard.

Named after Shackleford Banks, the southernmost barrier island in the Cape Lookout National Seashore chain of North Carolina, the catamaran was constructed to US Coast Guard Subchapter T standards. The speed and stability of the twin-engine hull design are ideal for specialised nearshore/mid-shelf hydrographic and geophysical survey operations.

To reduce survey mobilisation costs, Shackleford is outfitted with fully dedicated and redundant survey systems, including a Kongsberg EM 2040 MKII multibeam echosounder that is deployed through the vessel's moonpool via a retractable strut. Dimensional control (dimcon) surveys utilising applied metrology techniques orient the vessel's primary IMU/multibeam reference systems, and a network of discrete benchmarks set within the vessel's reference frame allow accurate and repeatable lever arm calculations to all survey sensors.

Shackleford integrates the signature Teknicraft Design symmetrical and asymmetrical combined hull shape, bow wave piercer, and a patented hydrofoil-assisted hull design. The hull and the hull components are designed to break up wave action and ensure reduced drag while enhancing passenger comfort. This design is proven to have both low-wake wash energy and increased fuel economy. This advanced hull shape was custom-designed using digital modeling and computational fluid dynamics (CFD) analysis testing.

The vessel's design offers all passengers and crew a smooth ride and comfort, as the hull provides a cushioned effect when encountering waves. The design also offers improved fuel economy, as the vessel consumes approximately the same volume per nautical mile throughout the cruising speed range of between 18 and 24 knots.

With a large fuel capacity of 1,500 gallons (5,678 litres), the design is licensed for up to 16 day passengers and has live-aboard accommodations for up to 10 passengers.

The propulsion package includes two fixed-pitch propellers powered by twin Caterpillar C18 US EPA Tier III diesel engines, each rated 803 bhp (598 kW) at 2,100 rpm and driving ZF 665V remote-mounted gearboxes. This arrangement delivers a maximum speed of 27 knots though it also allows a low cruising speed of 3.5 knots to ensure the accurate collection of survey data.

Onboard facilities include three cabins with a total of eight berths, two heads, a galley, large laboratory spaces, and a full range of hydrographic and marine geophysical instrumentation with which a variety of survey missions may be conducted.

The electronics include GPS and a radar from Furuno, a Simrad autopilot, and an ICOM VHF radio. Power for these and the other onboard systems is supplied by two Northern Lights 21kW generators.

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