Since the late 1980’s, All American Marine (AAM) of Bellingham, Wa. has built more than 40 aluminum catamarans from 48 to 135 feet long for a wide variety of operations from fast ferry to whale watching.
The vast majority of these craft have been designed by naval architect Nic de Waal’s Teknicraft Design office in Auckland, New Zealand, which has over 150 vessels at work around the world. His patented design has also become popular for research and survey boats where excessive motion of small monohulls affects the ability to perform the precise measurements needed in survey work.
As offshore engineering and research has grown in importance in recent years, AAM has launched over a dozen research/survey vessels from 48 to 134 feet—and become Teknicraft’s exclusive North American builder.
The latest is the survey catamaran R/V Shackleford, built for NV5 Geodynamics, a fast-growing company that perform surveys of all types throughout the U.S. and had previously acquired a fleet of six craft for its marine work, including two vessels built in Washington state.
To participate in the development of the offshore wind farm sector on the Eastern Seaboard, NV5 Geodynamics needed a bigger platform equipped to handle this challenge and was impressed by two AAM-built catamarans delivered to Duke University’s Marine Lab and Blue Tide Puerto Rico. Shackleford is a development of these designs and is based in Beaufort, N.C.
Like all Teknicraft, these sister ships have asymmetric semi-planing hulls with wide, flat sterns and multiple chines on the inside forming stepped sides in the tunnel to break up wave action. For offshore use, the design includes a central v-shaped wave deflector under the foredeck and a wave-piercing bow shape to reduce pitching in rough seas.
For boats intended to cruise at speeds over 15-18 knots, de Waal’s foil patent covers the use of a full-width horizontal aluminum wing amidships in the tunnel, so is only visible when it the boat is hauled out. It is matched with a pair of short stabilizer fins on the inside of the hulls astern. At the maximum cruising speed of 18-24 knots, the wing lifts the forward third of the hull reducing resistance has been shown to reduce fuel consumption by 10-20 percent. The design also optimizes fuel efficiency at the 3.5 knot minimum survey speed.
After extensive discussion with the customer, Teknicraft applied real-time data from an earlier design to refine the hull and hydrofoil shape with computational fluid dynamics, while digital modeling was used to produce a safe, functional deck plan, comfortable accommodations, and all systems engineered for ease of maintenance.
A fully equipped galley and dining area serves the crew, which is accommodated in three cabins. Crew security is provided via redundant safety systems including a FLIR thermal imaging camera, video monitoring feeds, and advanced fire suppression technology.
The large working deck aft is dominated by the tall housing for the retractable strut that lowers the primary instrument – a Kongsberg EM 2040 MKII Multibeam Echosounder – through the moonpool.
Multi-beam side-scan and sub-bottom sonar are deployed from Universal Sonar Mount poles swung out from the port and starboard rails, while heavier hydrographic instruments are towed from a stern gantry with twin hydraulic winches and a second helm station. The upper deck holds a third helm position and a Morgan crane.
The wide pilot house has multiple screens to monitor the performance, position and state of all the underwater survey gear. A notable feature is the use of black coatings and laminate on all surfaces – overhead, walls and floor – to reduce glare. The radar and autopilot are from Furuno, the VHF is a Simrad AP-70, and Internet service is available via a I-Com Proxicast Transit Duo. Five computer stations are supported by a high-capacity SSD server with 10 GB network connections.
The exceptional width of the hull at the waterline, compared to that of a standard catamaran, affords a reasonable amount of space in the engine room, which allows for good access to the EPA Tier 3 Caterpillar C18 ACERT in each hull. This 18.1 liter diesel engines are rated at 803 bhp at 2100 rpm driving conventional propellers via ZF 665V remote-mounted gearboxes. A 20 kW Kohler genset is mounted at bench height for ease of maintenance.
“We consider the boat a precision survey instrument, purpose-built for the specific survey environment and wrapped around the ideal sensors for a specific set of missions,” said Chris Freeman, NV5-Geodynamics senior vice-president. •