Engineers prefer reliability centred maintenance
In the shipping industry, traditional maintenance plans are often based on a combination of recommendations from manufacturers, legislation, company standards, and – to a lesser extent – real-time data. As a result, they can suffer from a rigidity that doesn’t properly reflect the working conditions of a marine vessel.
For example, section 3.1 of The UK Maritime and Coastguard Agency’s Merchant Shipping And Fishing Vessels (Lifting Operations And Lifting Equipment) Regulations 2006 specifically states that “in order to ensure that all parts of lifting equipment and related equipment are kept in good repair and working order, regular preventative maintenance [emphasis added] should be carried out”. These regulations are less than a decade old, but they already reflect an antiquated approach to vessel upkeep that is based upon the presumption that regular human interaction is the best way to keep a vessel running.
For many businesses, this kind of approach can result in a level of standardisation imposed upon their maintenance schedules that can have a detrimental effect on the operational life of a vessel. This is in large part because avoidable human intervention is the root cause of up to 60% of mechanical failures. Therefore, ensuring that maintenance is scheduled in a way that best meets operational needs, whilst also identifying potential damage before it escalates into machinery failure, is critical to protect the bottom line.
There is an elegant simplicity to the belief that greater reliability will result when infrastructure is maintained more frequently. However, a well-trained engineer understands that as long as the operational state of all infrastructure assets are fully accounted for, managing, maintaining and repairing a modern vessel efficiently and cost-effectively can be achieved with better results for a fraction of the cost, and in a fraction of the time.
Maintenance recommendations from manufacturers are not always based upon real experience data, and until relatively recently could often just be simple extrapolations from laboratory testing. This is due, in part, to the limited feedback that OEMs receive from users beyond the guarantee period. It is also a reflection of the fear of product liability claims, which cause many suppliers to encourage additional checks above and beyond what may actually be required. The challenge for engineers is that these checks have the potential to impact machinery negatively and result in avoidable, maintenance-induced failures.
The insurance industry has warned of the dangers of the lack of real-time data available to ensure that catastrophic failures, and therefore claims, are avoided. As Simon Stonehouse of the International Union of Marine Insurers stated at the 2015 Asian Marine Engineering Conference in Singapore: “My concern is that ships are getting more complex due to green issues and that simply means that there is more to go wrong. Big data is coming. That means underwriting is going to become more dispassionate and less about personal relationships. That is going to mean that insurance is going to be based on your ships’ data as regards training, equipment and track record. Once that happens, insurers are going to be looking at these issues much more closely when it comes to underwriting and we are likely to see more and more ships being declined.”
Without the systems in place to monitor the operational performance and condition of vital machinery, shipowners may find themselves with large repair bills that are not covered under their insurance policies if they do not fully embrace condition monitoring.
The current era of market volatility has cast doubt over the industry’s traditional cyclical model, with uncertainty challenging the commercial case for investment in condition monitoring strategies – even though industry leaders including China Classification Society and Lloyd’s Register have publicly stated their belief in the positive benefits of condition monitoring. Given that vessels entering service today are likely to have an operational lifespan approaching a quarter of a century, the operating and maintenance requirement is going to have to change and adapt.
For this reason, owners who have traditionally determined their vessel investment strategy based upon an expectation of a reliably fluctuating market might be better served by opting for vessels which can maximise their return at any individual moment. It’s a view shared by Magnus Miemois, director of field services at Wärtsilä, who believes that “for shipowners, uptime is the most crucial factor affecting quality and profitability”.
One of the companies that has prioritised condition monitoring tools as its first line of defence for identifying issues with critical machinery and equipment is Doosan The company has recently agreed to install 36 Parker Kittiwake LinerSCAN online monitoring systems on six new vessels. The LinerSCAN system uses magnetometry to quantify the iron in used cylinder oil and helps to identify the ingress of catalytic (cat) fines that can damage the cylinder liner. Scrutinising the level of wear in the system therefore not only helps extend operational life, it also prevents unanticipated downtime, and repair bills from otherwise unseen accelerated wear. Benefits that are particularly appreciable in light of an average liner replacement cost of almost US$150,000. Such a wear mode could not be acted upon with a lab test as the episode requires real time action.
Veritas Petroleum Services warned in August in a technical newsletter that routine fuel quality testing to the ISO 8217 standard for ignition and combustion characteristics could still fail to detect potentially damaging levels of cat fines. As in the case of the tanker that Veritas referred to, on which a majority of the piston rings were found broken and a liner crack was detected on one of the cylinder units, this can lead to a permanent loss of propulsion and significant downtime undergoing repair.
A tool such as the Parker Kittiwake Cat Fines Test Kit (launched last month) provides simple to understand, accurate results onboard in a matter of minutes. It is only by offering seafaring engineers the ability to identify potentially troublesome symptoms that they can take action before damage occurs. Such steps then give operators the opportunity to perform preventative maintenance and/or take preventative action during the ship’s passage to the next port and avoid expensive downtime.
It is not only bunker concerns that are driving today’s condition monitoring. But the high cost of fuel in the past couple of years has directly contributed to the advent of slow steaming to lower costs. When vessels travel more slowly, cold corrosion can become an issue as the cooler temperatures in the engine cause sulphuric acid to form on the walls of the cylinder liner. The acid’s corrosive effect can cause extensive damage to the system, but its negative effect is entirely preventable with the correct training and cylinder oil optimisiation. The Parker Kittiwake Cold Corrosion Test Kit provides a clear indication in less than five minutes of the presence of corrosive elements in used cylinder oil, without the cost or time delay incurred by sending samples ashore for laboratory analysis.
If used in tandem with a ferro-magnetic analyser, such as the Parker Kittiwake Ferrous Wear Meter, engineers can spot both abrasive iron and corrosive iron compounds in minutes. Combining online and offline tools gives operators the tools they need to avoid damage, maintain productivity and increase profitability.
The proven benefit of a reliability-centred maintenance strategy and a thorough approach to proactive condition monitoring is reduced maintenance costs and less downtime. By focusing on the most important functions of the system and not relying solely on engineers’ eyes and ears, operators can avoid or remove maintenance actions that are not strictly necessary. The installation of these tools in combination with an engineer’s experience is the key to productive, infrastructure-focused maintenance – and it is often by eliminating ineffective preventative maintenance tasks that machinery and engine reliability can be optimized, and unnecessary downtime eliminated.
Data and equally as important useful information facilitates awareness and understanding, and can provide a motivation to change. Without it, conclusions are influenced by inaccurate assumptions. This leads to decisions being made without a full understanding of the big picture, and luck becomes a contributing factor to a vessel’s output – an outcome no good engineer can abide.
