VESSEL REVIEW | Kai Hamana – Environment-friendly feed barge handed over to New Zealand King Salmon

New Zealand King Salmon has taken delivery of a new feed barge built by Z189 Shipyard in Vietnam.

Designed by Australian naval architecture firm Southern Ocean Solutions in compliance to Maritime New Zealand rules, the 30- by 10-metre Kai Hamana has capacity for 330 tonnes of pelletised feed in six silos, allowing regular feeding to be conducted even during days of bad weather. Up to six different grades of feed can also be stored at any given time.

"The owner required a custom vessel that was specifically designed to fit within the permit parameters of the site where it is to be deployed," Scott Keane, Construction Manager at Southern Ocean Solutions, told Baird Maritime. "This could maximise feed storage while minimising environmental impact."

Keane added that the barge is designed to have an embarked crew, though the vessel may also be operated autonomously if required. It will be permanently moored in Picton on South Island, where it is slated to operate for up to 30 days before requiring replenishment of its generator fuel and stores.

"The design from inception emphasised all-around efficiency and reduced environmental impact. This also included being painted in such a way that the vessel blends in with the local environment and coastline as much as possible."

The challenges in designing and building Kai Hamana lay mainly in dealing with the permit criteria being very prescriptive with a maximum vessel height and footprint. The owner required an innovative vessel that was efficient to operate and was suitable for long service periods. Also, construction was adversely affected by the Covid-19 pandemic, particularly with regards to working amid disruptions in the supply chain.

"We have two more feed barges currently under construction," said Keane. "These new vessels are further developments of Kai Hamana's design and also have hybrid power plants, ensuring greater efficiency and quieter operation at night."

An advanced feed system supplied by the AKVA Group uses high volumes of low-pressure air to deliver pelletised feed up to 1,000 metres away from the vessel. The feeding rate will be carefully monitored to maximise efficiency and minimise wastage. Selectors are fitted to allow feeding to 36 different cages, and feed can be discharged from all six silos simultaneously.

Power for the onboard systems is supplied by three Cummins generators, which all run on low-sulphur diesel and consist of two 220kVA sets and a 24kVA unit. The accommodation spaces meanwhile include a mess and cabins for up to four crewmembers.

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