Panolin business development manager Phil Cumberlidge explains the facts and fiction of environmentally acceptable lubricants (EALs) and concerns with poor operational performance of some EALs
Panolin business development manager Phil Cumberlidge explains the facts and fiction of environmentally acceptable lubricants (EALs) and concerns with poor operational performance of some EALs, particularly stern tube lubricants, in container ships
With the capacity of container ships ever increasing, the reliability of the propulsion, steering and stability systems to ensure vessels achieve on-schedule arrivals in ports becomes more critical, and EALs play a crucial role in this.
Firstly, let us define what an EAL must do – it must have a minimal effect on marine life; therefore it must biodegrade, it must have minimal toxic effect and must not accumulate in the organs of marine life, being transferred up the food chain. The EAL must also perform well in the machinery it is lubricating.
From an environmental perspective, the US Environmental Protection Agency (EPA) led the way in their vessel general permit (VGP) requiring that vessels entering US waters must use EALs in “oil-to-sea interfaces and classing three lubricant types as meeting biodegradability” requirements:
Polyalphaolefins (HEPR, otherwise known as PAOs, synthetic hydrocarbons, or ‘man-made’ mineral oils), are not included in the EPA list of biodegradable base oils in their environmentally acceptable lubricants document EPA 800-R-11-002 Section 2, of Nov 2011, or in their presentation Overview of the Final 2013 VGP of 6 November 2013, as they are only biodegradable in low viscosities. However, technically, the International Standard ISO 15380 (for hydraulic lubricants, industrial oils and related products) adds HEPR to the other three lubricant types, as ISO 15380 is not involved with environmental performance of lubricants, only with technical properties and conversion recommendations from mineral-based oils.
Some EALs are not solely made from one base oil type; they can be blends of PAO and ester (typically unsaturated), to combine minimum performance and give the minimum requirement for biodegradability, or they can be a mix of saturated ester to provide performance requirements and unsaturated ester to reduce cost – the lower performing unsaturated ester being lower cost than the robust saturated ester.
So, how does an original equipment manufacturer and consequently, a vessel owner, choose the right EAL for their equipment to provide optimum operational performance and reliability of the equipment and therefore the scheduled operational availability of the vessel?
Reliability and long life come from the combined high performance of the base oil and the additives selected. Issues such as those listed below have become evident with some types of EALs:
These problems cause more frequent system and lubricant monitoring, maintenance, lubricant top-up, system draining and refilling, transport and disposal of used oil and costs of replacement parts. These are the obvious direct costs of using inferior performing/life oils – not to mention the hidden costs of the paperwork to administer all these monitoring/inspection/testing/re-ordering/logistics operations, and lost revenue due to equipment downtime/failure – and the embarrassment of late deliveries of consignments.
Currently, the EAL world is in turmoil, with many issues reported of poor performance of EALs in equipment where previously mineral oils had proven to work
Stern tube lubricants sometimes have a short life of only 2-2.5 years before acidity of the lubricant increases, viscosity dramatically increases, or the stern tube is contaminated with stinking black sludge that blocks seal oil-feed pipes and bearing oil lubrication washways. Many vessel owners who adopted EALs early in the current VGP2013 lifespan have fallen foul of these lower performing, short-life EALs. Most are changing to the better performing EALs. The announcement earlier in this year by DNV GL of a joint development project with several marine insurers and the University of Sheffield in the UK to investigate the increase of stern tube bearing failures will shed light on whether EALs are to blame – and if so, which base oil lubricant types are prone to operational failure. Slower steaming with larger, heavier propellers requires the highest oil film performance from the stern tube lubricant.
Fully saturated synthetic esters are leading the way in reliable, high performance and long-life marine lubricants for stern tube/CPP and thruster propulsion, rudder and bow thruster steering and vessel stability systems such as fin stabilisers and ballast control. They have the benefit of being environmentally considerate and reducing a vessel’s carbon footprint. Documented monitoring of real-life use of Panolin saturated synthetic esters shows that in all areas of fluids and lubricant use: stern tube, hydraulics and gearboxes, the robust chemistry of saturated ester technology can enable up to 10 times the operational life of mineral oils, when combined with best management practice for lubricants – looking after the oil and having regular sample checks.
It is the lubricant manufacturer’s job to tell you about the key performance indicators of their lubricant(s) – consult them and ask them what specific EAL base oil technology they use. If they say “We use ester technology”, ask if it is natural, unsaturated, or a blend of saturated and unsaturated ester, or if it is the ‘real thing’ – a fully 100% saturated synthetic ester.
New technology is ensuring propellers for the world’s largest container ships have an exact fit between the design and manufacturing geometry
While the 7.5-m diameter propeller that welcomed delegates to this year’s SMM conference in Hamburg was certainly impressive, an even larger unit – in fact, the world’s largest so far – was awaiting transfer at the city’s docks.
The Mecklenburger Metallguss GmbH (MMG)-designed and produced unit weighs in at 110 tonnes and measures 10.5 m in diameter. It had come by road from MMG’s production facility in Waren an der Müritz in Mecklenburg-Western Pomerania, for loading onto container ship Hyundai Supreme at the port of Waltershof, with the assistance of Hamburger Hafen und Logistik’s HHL IV floating crane. Hyundai Supreme set sail for South Korea on 16 September and was under way at the time of writing.
Upon arrival at the port of Busan, the propeller will be transferred to Daewoo Shipbuilding & Marine Engineering, where it will be mounted on the first of 11 vessels being built by Daewoo and Samsung in a 5:6 split contract for Mediterranean Shipping Company (MSC).
MMG is designing and producing propellers for all 11 of the single-screw vessels, with six 10.4-m diameter, 117-tonne, six-bladed units going to the Samsung vessels and five 10.5-m diameter, 110-tonne, five-bladed units going to the Daewoo vessels. MSC’s new vessels will have a capacity of 23,000 TEU, making them the largest container ships in the world.
Other significant jobs MMG currently has on its books include nine 10.1-m diameter, 94-tonne five-bladed units for CMA CGM’s 22,000-TEU vessels under construction at Hudong-Zhonghua Shipbuilding and Shanghai Waigaoqiao Shipbuilding in China, and five propellers for HMM’s 23,000-TEU vessels to be built by Samsung.
MMG will utilise its virtual contact test (VCT) technology to ensure the units are fitted correctly. This optical measurement system was invented by MMG and involves the prop shaft being measured by an MMG team, with the propeller then manufactured to fit exactly, based on these measurements. VCT removes the need for male and female gauges and extra scrapping allowance entailed when using the traditional blue-bedding method. VCT is possible because all MMG propellers undergo 3D scanning, both during and at the end of production, giving the company detailed knowledge of the surface contours of the entire propeller. This exceeds the ISO standards that specify particular points of particular sections of the unit are tested. The exact picture of the propeller this process creates ensures a true fit between design geometry and manufacturing geometry.
While not utilised on the propellers being manufactured for MSC’s vessels, MMG is running research projects in the areas of 3D printing, additive manufacturing and production automation. While these techniques have been used at smaller scales for some time now, the complexity of the processes increases exponentially with component size. MMG’s sales and project engineer Arne Falkenhorst noted the company is optimistic it will successfully upscale these techniques.
Energy saving and digitalisation are key themes for Becker Marine Systems in the face of rising fuel costs and the 2020 low sulphur fuel directive.
Becker Marine Systems co-managing director Dirk Lehman commented “Our main Manoeuvring Systems and Energy-Saving Devices divisions continue to develop in a positive way, especially in the field of energy-saving solutions, demand continues to rise strongly, as energy efficiency plays an ever-increasing role as a result of rising fuel costs and stricter environmental regulations in future.”
The ship supplier has developed new digital product enhancements, which can monitor ship operations and detect wear early. For example, the Becker Intelligent Monitoring System (BIMS) enables energy-saving autopilot operation and improves the effectiveness of ship operations.
“Besides this, we are currently developing a new Becker Mewis Duct for twin-screw vessels that can lower energy consumption by up to 4%”, said Mr Lehmann. He said this product innovation is of particular interest for LNG carriers, shuttle tankers and large container ships.
Elsewhere, a Becker Marine Systems pilot project was presented in August this year, which ensures large container ships can turn off their auxiliary diesel engines and during downtime obtain the power needed for onboard operations from a new type of mobile generator.
Becker Marine Systems developed the mobile Becker LNG PowerPac power plant along with its subsidiary, HPE Hybrid Port Energy. A compact system the size of two 40-foot containers, this unit combines a gas-powered generator and an LNG tank to provide power for ship operations while at port. Hazardous emissions, such as sulphur dioxide, fine dust and nitrogen oxides, which otherwise occur during operation of the ship, can thus be avoided or significantly reduced.
The tests were carried out on Hapag-Lloyd ships at the Hamburger Hafen und Logistik pier. All parties involved are very satisfied with the results of the pilot project.
“We are in talks with a number of European and Chinese ports and are confident the Becker LNG PowerPac can prevail on the market”, said Mr Lehmann.