Net cleaner a world first

Marine and Aquaculture Contracting Ltd (increasingly known as MAC) is a small, locally owned and operated family company based in Picton.

MAC began three years ago after establishing there was a need for temporary, part time labour for the marine and aquaculture industries in the Marlborough Sounds. It was a shrewd idea and a diverse range of companies – both local and nationwide – were soon attracted, including contracts to drive tourism vessels, work with a local mooring services company, vessel deliveries and providing dive support and general labour to the aquaculture industries.

As the demand for services increased, it became obvious that the next step for MAC was to purchase a multi-purpose vessel allowing it to become more self-sufficient and expand the range of services MAC could provide. 

After searching internationally, Seawatch, a 23metre Catamaran was purchased from just over the hill in Nelson. Seawatch has a 90-tonne payload with crane and lifting capabilities, making it an ideal workhorse for the aquaculture industry and transport of general freight, fuel, building and construction materials or rubbish and recycling. Modifications are also currently being made to the vessel, so that mooring services for Marlborough Sounds residents can be offered from October. The 15-cabin vessel can also transport and accommodate work crews and other personnel in comfort and safety. 

MAC has now developed what it believes to be a unique profile within the region offering companies in the marine industry the ability to retain their small, core team whilst employing temporary contractors during times of increased workloads or unexpected projects.

Cole Warwick and Paul Luxton are qualified Inshore Launch Masters, Marine Hiab and Forklift Operators and Aquaculture Divers.

Seawatch specs:

Length O.A: 23.0m

Beam: 9.7m

Max Draft: 2.30m

Gross Tonnage: 125 tonnes Dead Weight: 186 tonnes

Speed: 9 knots cruise

Pay load: 80 tonnes

Main Engine: 2 x Scania- 520kW combined

Bow Thruster: 150kW Hydraulic

Generators: 1 x 60kVA Perkins (415/240V), 1 x 38kVA Perkins (415/240V)

Hydraulics: 671 Detroit 155kW, 3500PSI

Deck Crane: Palfinger 9TE m

Navigational Aids: 1 x VHF, Gyro, Echo Sounder, Radar, GPS, Chart Plotter.

Total Berths: 15

Other: Galley (1), Mess (2), Office/ ROV shack (1), Showers (2), Heads (2)

In partnership with Boss Net Washing, MAC can offer net cleaning services using the fully-automated net-cleaning robot, AutoBoss, a world first.

Developed over five years by Marlborough-based marine engineer, Andy Fairhall, the system – a 850kg machine, 2.5m x 2.0m x 1.6 m when fully extended – sits on a pontoon and attaches to the side of salmon-holding pens with wheels, which roll along the sides to clean the nets. The on-board adjustable PLC can be programmed to clean the nets where the cleaning is needed, which means costs are kept low. At the single-pass pre-set manufacturing rate, the self-propelled AutoBoss can cover up to 1500m2 of net per hour and can be programmed to a specific wash and depth mode. High-pressure water is delivered to the wash-head, attached to the AutoBoss by an umbilical, which extends up and down the nets to clean them. High-pressure water is not used to keep the cleaning head in place – independently driven propellers do that – so the four-disk head uses 100% of the high-pressure water fed to it to clean the nets.

The Power Pack Assembly contains all of the components that make the AutoBoss operate. The key components are:

  • The Engine System provides power for all of the other AutoBoss systems
  • The Electrical System is split into two separate parts: the engine and the Boss command system
  • The Hydraulic System is driven via an engine power take off (PT)) on the timing case
  • The High-Pressure Water System is supplied with water drawn from the environment.
  • The Walking Wheel Assembly is designed to hold the Boss on the net and move the unit along the net.
  • The Winch Assembly automatically lifts and lowers the cleaning head.
  • The Washing Head is comprised of 4 cleaning discs that each have 3 water jets.
  • The Umbilical takes HP water from the Power Pack Assembly to the washing head and the HP water vents out of the washing head water jets and removes the biofouling.   
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