Sanford: A Leading Fisheries Operator

Sanford is a New Zealand based fisheries operator, who own and operate a fleet of deepwater and inshore vessels. Their inshore vessels bring their catch straight to shore, while their six deepwater vessels process and freeze fish products at sea during their expeditions which can last up to eight weeks.

TEG Risk Machine Safety Risk Assessment

Sanford approached the TEG Risk team of safety engineers to conduct a  risk assessment. The risk assessment highlighted the need for a Performance Level ‘d’ safety solution that would stand up to the high-demand hostile environment, with a design that would be re-usable across the entire fleet. Sanford and Fluid Power Solutions then worked alongside TEG Risk to find a world-class, innovative solution

To achieve Performance Level ‘d’ required by the risk assessment, electronic monitoring logic devices like safety relays are commonly used for most machinery – however traditional electrical based components, especially emergency stops, typically fail within months of fitting due to UV exposure, rain, heavy seas, and seawater hose down under pressure.

The new solution needed to ensure that machines remained operational at all times, despite the challenges of the hostile environment. The high salt of the seawater meant the safety design needed to be made from a non-corrosive material. Added to this, as well as operating at sea, all machinery is hosed down with seawater at the end of the shift, therefore the solution also needed to withstand a frequently wet environment.

 The lead engineer on this project, Charles Webb has a background in design engineering and machine building, as well as a Bachelor of Engineering Technology specialising in Mechatronics. Guided by data gathered from the risk assessment, an understanding of the environment, and a comprehensive knowledge of engineering Charles and the team at Fluid Power Solutions designed a bespoke solution to this unique safety issue.

TEG Risk’s ‘Safety Logic Function’ Solution

Often a safety control system can be constructed or retro-fitted with off-the-shelf components. But in this case with a requirement for a performance Level ‘d’ safety solution, operational within a hostile and corrosive environment, the safety control system to be designed from the ground up. 

A safety logic function was needed. It needed to be conservatively designed, then carefully analysed and refined to ensure reliability and safety integrity. The design needed to be something quite novel.

Charles narrowed down the medium to hydraulics – a reliable medium already utilised across the Sanford fleet with a high immunity to seawater. Components such as valve manifolds are  able to be manufactured from corrosion resistant metals, making a hydraulic system the most ideal.

The Process Started With A Risk Assessment

To understand the safety issues TEG Risk first carried out a risk assessment, to ascertain which machinery safety standards were met, and which were not. After these were well documented, they were assessed and scored. The risk assessment then determined the performance level required, which informed the initial conceptual design. After Fluid Power Solutions completed the detailed design, it was analysed with a Fail Mode Effects Analysis (FMEA) to locate any design defects, which were then refined. 

Design Requirements Maritime

Design requirements were unique to the maritime environment. Both the design process and the eventual solution needed to be reliable and withstand the hostile environment.

• Easily diagnose an undetected fault
• Cost of downtime is a significant factor – avoid shutting down the operation
• All machinery is production critical – low redundancy
• Seawater, high salt – corrosive. Hose down for all equipment
• Electrical emergency stops fail in months, not always wired appropriately
• Unexpected start-up, hold-to-run controls (jamming, defeat etc.), controls left in the ‘run’ position 

To mitigate the above issues the following components the design was engineered with the following components in mind:

• All-hydraulic manifold
• Modular construction
• Series connected inputs
• Reset circuit for diagnostic coverage
• Expandable EDM inputs – External Device Monitoring
• Valve feedback
• Pressure feedback
• Pilot pressure feedback

The Safety Design Needed To Be Modular and Reusable

As well as the environmental issues outlined above, the safety design needed to be modular and reusable, being able to be bolted together, pulled apart and reused. It also needed to be designed with simplicity in mind, both for end-use and for ease of manufacturing. This was not a one-off safety solution, but one that, after testing and trialing, was required to be rolled out across the in-shore fleet, and finally the deep sea fleet of Sanford vessels.

Safety And Compliance Were Essential

It was paramount that the workplace was made safe, and compliant with New Zealand’s Safety of Machinery standards – AS/NZS 4024, and in accordance with the requirements of the Health and Safety Work Act. This was accomplished. Not only was a safety solution successfully designed and delivered, it was designed in such a way that it was available for all the machines.