John Rafferty of Elemental Manufacturing has designed and manufactured essential components and injection moulding tools for the environmentally harmonious pen made for Australian salmon farming business Huon Aquaculture. A world first in aquaculture, the salmon protection pen not only protects the fish, but also safeguards the seals that want to eat them and the staff who might be caught in the middle.
Huon describes the pen as ‘revolutionising the salmon industry worldwide’, and praises John’s involvement as instrumental in realising the design and producing parts for half the cost of metal fabricated designs.
Mr Rafferty explains that seals in most countries outside of Australia and New Zealand are destroyed by farmers as a pest. These seal-proof pens are designed to protect seals and prevent them from being destroyed as a result of their continual attacks on the pens to get at the fish.
The new pens employ a double-net system to protect the salmon and prevent seals from ramming themselves against the inner netting to get to the tasty fish inside. The pens also allow easier and wider egress for the disappointed seals.
According to Mr Rafferty, the pens also create a safer working environment for staff with a new flat walkway that also helps keep aggressive seals away from workers. Many suggest this revolutionary pen design should be adopted as a new global standard.
One of the important parts John designed for Huon was the triple collar stanchion, which he says is the first and only 450mm plastic injection moulded triple collar stanchion for aquaculture. At 2.5 metres in length and weighing over 50kg, this part is used to support the entire pen and houses the three flotation collars that keep the pen afloat. The design also includes a fully enclosed walkway and handrail for workers to be able to move safely around the entire circumference of the pen.
Some of the benefits of replacing the existing metal stanchions with an engineering polymer include reduction in price of more than 50 per cent compared to the current metal fabricated units; significant weight saving from 160kg down to 55kg, which allows for larger pens and therefore increased and more efficient production; lower energy requirement to move the lightweight pens; longer service life with the polymer units designed to last at least 10 years, with an expectation of a serviceable life of 20 years or more; and significant amount of controlled flexibility in the polymer stanchions compared to metal units.
Following the first success, Huon Aquaculture has again engaged John’s services to commission a larger, heavier version of the product for their continuing expansion. The next size, still in tooling production, will weigh more than 65kg.
To support the Australian polymer industry, John’s company worked with a local Australian injection moulder, Wasson Engineering Plastics. Wasson assists Elemental Manufacturing with commissioning and running of the moulding tool.