Based in the pristine waters of the Marlborough Sounds, New Zealand King Salmon (NZKS) is the world’s largest salmon farmer, raising their high-quality King salmon from egg to smolt to final product. This includes the ‘king of King salmon’ – the Ōra King Tyee salmon, which can get up to a whopping 30 pounds and be over a metre long.  

FPS’ expert pneumatic technicians designed and built a custom – and adjustable! – harvesting machine, known as a percussive stunner, for NZKS to humanely and safely process its fish.  

Everything from the mounting frame to the internal components was designed specifically for NZKS from a range of custom-made and off-the-shelf components. Parts were laser-cut locally by Fabriweld and assembled in-house at FPS. 

one fish, two fish

Long-time FPS compressed air and vacuum technician Randyl Illsley said the biggest challenge to the build was ensuring the machinery could adapt to a variety of salmon sizes.

NZKS needed to be able to use the stunner for everything from its smaller brood stock, which are closer to 3 kilograms in weight, up to its massive, premium Tyee salmon.

Randyl designed the unit so the stunner component, a pneumatically driven piston at a force of 837 inch-pounds at 100 PSI, could be raised and lowered using special pins. The side plates can also be adjusted, ensuring fish of varying sizes can fit between them. What’s more, the entire unit can be set to a specific angle to make the task more efficient. In the unit’s first trial, NZKS staff were able to process 270 fish in the first two hours – NZKS staff estimate it’s twice as fast, as well as a safer alternative, than their previous equipment.