An Environmental Package with Railko Sterntube Bearings
15 July 2004
Railko, manufacturers of composite sterntube bearings, have tested and approved an environmentally friendly sterntube lubricant for use with their bearings, including the new Sternsafe™ bearing.
Hydrox Bio 68 is a readily biodegradable and non-toxic sterntube lubricant manufactured by UK based Vickers Oils. The oil is already in service in a large and growing number of vessels fitted with conventional white metal bearings. Early acclaim for Hydrox Bio 68 came with the award to Vickers in 2003 of the internationally prestigious Seatrade Award for the Protection of the Marine and Atmospheric Environment, since when it has established a significant position in a number of environmentally conscious areas of the marine industry including the cruise, tanker, car carrier, ro-ro and container markets. Hydrox Bio 68 is accredited under the Lloyds Product Verification Scheme, and is Type Approved by ABS and BV.
Hydrox Bio 68 offers clear advantages over conventional system oils and alternative approaches to the environmental issue.
Technical Performance:
It offers a high standard of lubrication, thus offering the prospect of optimum bearing life
Hydrox Bio 68 shares with other Hydrox sterntube oils the ability to absorb ingressing seawater and, in so doing ensures that lubricating and anti- corrosive performance is maintained thus protecting the bearing, shaft and liner. This means that vessels can continue in operation even with significant quantities of water in the oil and avoid expensive out of service costs
It has been designed to be compatible with sterntube seals and so avoid the need for premature seal replacement. As such Hydrox Bio 68 is already approved by a number of seal manufacturers
Ecological Credentials:
It is truly “Readily Biodegradable” according to the internationally recognised OECD 301B test
Hydrox Bio 68 is non-toxic, and has been independently tested on a full range of key aquatic organisms
Hydrox Bio 68 is produced from renewable resources, a critical criterion of ecological acceptability
Railko composite sterntube bearings are specified by shipowners worldwide where the benefit of reduced through life cost has been recognised. Railko bearings have been well known for many years for giving an effective seize proof solution that does not damage the shaft and can operate at full power on sea water lubrication in the event of a sterntube seal failure. These two factors give the shipowner the security of knowing that the vessel will always get home under its own power. This means the Shipowner will not incur costly towing charges and can arrange a convenient dry docking to suit charter commitments.
The new Sternsafe™ material has been specifically designed to have the lowest swell (immersed in water) of any oil lubricated material yet developed by Railko. This combined with very low wear rates gives a solution that offers maximum benefit to the sterntube seal.
Recognising a growing demand for a sterntube package offering an environmentally friendly approach, Railko evaluated Hydrox Bio 68 for compatibility with their established bearing materials, CY160LS and Sternsafe™. The work showed that the structural integrity of the bearings is in no way compromised by the use of Hydrox Bio 68 when compared with conventional system oils and that therefore the operating advantages offered by the Railko bearing are maintained. Hydrox Bio 68 has also been proven compatible with Railko materials at low shaft speed, boundary lubrication conditions, as required by turbine propulsion in tankers and LNG carriers.
“We were keen to offer a genuinely environmentally adapted system to the market. By working with Vickers and endorsing Hydrox Bio 68 sterntube oil with Sternsafe™ we can assure our clients, not only that there is no compromise in terms of bearing performance, but also that they are operating within the true spirit of care for the marine environment”, says Dr Graham Wells of Railko. “This is the solution that offers maximum security to both the Shipowner AND the environment."
