Much progress has been made in fully-synthetic based lubricants. So the focus should not only be on cylinders and engines, Iain White from ExxonMobil Marine Fuels & Lubricants reports
With the shipping industry still in a state of recovery as 2013 draws to an end, vessel operators are being[ds_preview] challenged to reduce costs and improve energy efficiency in order to remain competitive and to ensure profitability. These industry challenges, alongside new environmental legislation, provide an incentive for the development of advanced, pioneering technology solutions which can help fleet operators to safely and sustainably maximise the performance of marine vessel equipment and overall productivity as a result.
While cylinder oils and engine lubrication often receive the majority of the spotlight, all vessels are reliant on a number of other lubricants to help them function. Whether it’s an air compressor oil, gear lubricant, hydraulic fluid or grease, one equipment failure can bring the entire vessel’s operation to a halt. The good news is that advancements
in lubricant technology, especially when it comes to fully-synthetic based products, have seen significant breakthroughs with regards to preventing component wear and extending oil drain intervals, even when operating under harsh conditions such as the Arctic.
Protecting equipment in arctic conditions
In addition to the typical challenges facing lubricants used in marine equipment, in an environment such as the Arctic, lubricants also need to be able to cope with the »freeze« factor. As temperatures drop, conventional oils typically thicken and the increased viscosity reduces their »pumpability« – this is the oil’s ability to circulate throughout a piece of equipment, when pushed through by the oil pump.
Cold, thick oil is more difficult to pump, and if it becomes too viscous, it can stop flowing altogether. With limited or no oil travelling through a piece of equipment, particularly on start-up, critical components are not properly lubricated and can develop wear as they come into contact with each other.
Selecting an oil that can be pumped quickly to lubricate a machine, even in extremely low temperatures, is important to protect applications in cold weather. In order for an oil to protect equipment operating in these conditions, it must have a high viscosity index to resist excessive thickening under low temperatures and remain fluid for smooth and consistent circulation. The high viscosity index also ensures that the oil offers outstanding wear protection at extreme high temperatures as well.
Due to their formulation and resulting properties, advanced synthetic oils provide better equipment lubrication at temperature extremes compared to conventional oils. For example, they contain higher quality base stocks that enhance their performance capabilities even in sub-zero temperatures, enabling them to protect components soon after a piece of equipment is started.
Most conventional mineral oils are paraffin-based and therefore tend to thicken considerably as the wax molecules crystallize in cold temperatures. This extends the time needed to pump oil throughout an application and requires the equipment to work harder. By comparison, high performance synthetic oils contain no wax components. As a result, they remain fluid at much lower temperatures and continue to provide equipment with superior protection.
Advanced high performance synthetic oils
An example of a synthetic lubricant that can maintain its fluidity even at extreme low temperatures of down to -46 °C, is Mobil SHC Gear, a high performance heavy duty gear oil which has been engineered using the combination of a naturally high viscosity index (the ability to resist change in viscosity during temperature change) and a unique additive system, to enable outstanding performance under severely high or low temperature operating conditions.
Mobil SHC Gear oils are expertly formulated to deliver a number of performance advantages over conventional gear oil chemistries. For example, the range’s high oxidation resistance enables extended oil life up to six times (Increased oil drain intervals or extended oil life relates to the fluid performance when compared with conventional reference oils of the same viscosity grade. Improvements will vary based on unit type, operating conditions and application.) compared to standard mineral gear and bearing lubricants, helping to reduced scheduled and unscheduled maintenance. As well as providing superior protection in challenging environments, in statistically validated laboratory tests and field trials, Mobil SHC Gear fluids exhibited energy savings of up to 3.6 % ( Energy efficiency relates solely to the fluid performance when compared with conventional reference oils of the same viscosity grade in gear applications. The technology used allows up to 3.6 % efficiency compared with the reference when tested in a worm gearbox under controlled conditions. Efficiency improvements will vary based on operating conditions and application.) compared with conventional oils, demonstrating the savings that can be made when in investing in an advanced, high performance lubricant.
»Ocean Prawns« trawler extends oil drain interval to 120,000 hours
One example of a vessel that has benefited from optimised productivity as a result of using high performance synthetic lubricants, is the »Ocean Prawns« vessel. This is a modern shrimp trawler operating in the Arctic Ocean, off the coasts of eastern Canada and Greenland.
To ensure optimum productivity, the shrimp trawler’s engine gearbox must always perform reliably, even when operating with heavy loads in temperatures as low as -30 °C in winter and as high as 30 °C in summer.
Since 1996, »Ocean Prawns« has been using Mobil SHC Gear 220 in the main propulsion gear to help ensure reliable operation and performance, despite extreme operating conditions. (This proof of performance is based on the experience of a single customer. Actual results can vary depending upon the type of equipment used and its maintenance, operating conditions and environment, and any prior lubricant used.)
Combined with ExxonMobil’s Signum Oil Analysis programme, Mobil SHC Gear 220 has enabled Ocean Prawns A/S to extend the trawler’s main propulsion gear oil drain interval to 120,000 hours, despite operating conditions that included extreme temperatures and a new engine fitted during that time which significantly increased stress on the gearbox.
Maximising productivity
To fully ensure the reliability of shipboard equipment and lower maintenance costs it is important, as part of routine maintenance, to check the »health« of the lubricant and the equipment itself. Typically, it is advised that marine engineers perform quarterly oil analyses and annual system inspections.
For equipment maintenance, professionals who want an effective oil analysis monitoring programme, there is ExxonMobil’s proprietary online Signum Oil Analysis programme. Signum Oil Analysis offers engineers access and direct control of their lubricant sampling programme. Drawing upon a global database of marine equipment, the programme enables an accurate analysis of the lubrication needs, making recommendations and setting technical limits that can help to:
• increase reliability by detecting and preventing potential equipment failures,
• reduce unscheduled downtime,
• lower lubricant consumption and costly disposal.
Beyond oil analysis, visual system inspections should be conducted regularly to check and document the condition of systems. Inspection data can be used to establish the optimum time to perform maintenance on critical components. Compre-
hensive leak detection should also be performed, especially if excessive oil usage is noted during a routine system inspection.
By combining the use of advanced, high performance lubricants and an effective oil and equipment monitoring programme, marine operators, even in the Arctic, have the peace of mind that their equipment is protected and ready to perform.
ExxonMobil continues to evolve its product offer, with the recent launch of its environmentally acceptable lubricants range, Mobil SHC Aware oils.
Author: Iain White
Global Field Marketing Manager
ExxonMobil Marine Fules & Lubricants
www.exxonmobil.com/marinelubes-en/
Iain White
