The cage nets have to be washed regularly to remove the marine plants and animals that attach to the netting and block the flow of water to the trapped fish.
After the net is cleaned, it is sterilised to kill any fish pathogens that may survive the washing procedure and could otherwise cause disease and put the fish stock at risk. Nets normally require cleaning and sterilising approximately twice a year.
The cage nets are despatched from the Scottish fish farms in sealed wagons and, once at the Knox processing plant, are transferred into dirty storage areas where they await cleaning.
According to Roger Dehany, Director and General Manager of W & J Knox Ltd, “Like most manufacturing and processing companies, we are constantly having to find ways to reduce costs in order to maximise our profitability. When my fellow director, Jim Traynor and I bought this company, via a management buyout at the end of 2004, we recognised the need to restructure our processing operations in order to cut out wasteful activities and reduce costs.
The purchase of the MR108 +3 played a vital role in this business strategy and has improved our operational efficiencies by 80% in this area of operation.”
Prior to the purchase of a tower crane, Knox used forklift trucks to lift the heavy nets and cages from the sealed containers and then transfer them into the industrial washers. As these nets have an overall depth of 30 metres, this whole process proved to be awkward and inefficient. The additional length offered by the tower crane’s jib has made handling these products much more efficient.
Now, the tower crane moves the nets into the washer and then lifts into the sterilising unit. Finally, it lifts them into the clean area ready for any repair work required.
All of these processes are achieved without the need for intervention or the requirement for any other handling equipment. This operation is faster than before. It also avoids compromising the quality of the cleaning process, as the hook and strop are sterilised with the nets, thus reducing the possibility of the clean area becoming contaminated.
“Occasionally we have a problem with odour, due to the process of decomposition on the fouling attached to nets”, said Finlay Oman, Knox operational manager. “Being situated at the centre of a town and adjacent to a supermarket we needed to do something to alleviate this problem. We therefore installed a manifold with atomizing spray head to the crane that allows us to pump perfumed liquor into the atmosphere in an effort to mask the smell.”
“The MR108+3 is remote controlled and very easy to operate,” said Roger Dehaney. ”We have had minimal problems with it during its three years of operation, despite its heavy usage. It undertakes a significant amount of work each day, as it operates for seven days a week, covering two shifts, for a full 16 hours a day.
“This crane has become invaluable to our operation, as it makes the whole cleaning process so quick and easy. Also, the 30m radius covers 60% of the in-use area of the net washing site. Without the crane it would be impossible to achieve the turnaround within the tight time frame imposed by our client base. It has revolutionised our business.”
The MR108 +3 has a simple pedestrian operational system which, when coupled with inverter drives, provides a smooth hook movement which suits the requirements of W & J Knox’s net handling operation.
