1 January 2017 was a historic milestone in the protection of our polar waters for future generations. On that day, International Maritime Organization’s (IMO) International Code for Ships Operating in Polar Waters (the Polar Code) came into force. The Polar Code is aimed at protecting ships and the people aboard them, both seafarers and passengers, in the harsh environment of the waters surrounding our two poles, Arctic and Antarctic.
The Polar Code covers the full range of shipping-related matters relevant to navigation in waters surrounding the two poles, including ship design, construction and equipment as well as operational and training concerns. Also, search and rescue, the protection of the unique environment and eco-systems of the Polar Regions are covered by the Code.
The Polar Code and other initiatives within the marine industry have spawned a new era of environmentally friendly products. “In Wärtsilä, we strongly welcome any incentives for the further preservation of ecosystems and protection of the sea. We are also a strong promoter of water lubricated solutions that assist shipowners and operators to comply with the Polar Code and other environmental regulations,” says Benjamin Tornberg, Merchant Segment Manager at Wärtsilä Seals and Bearings.
Reducing the risk of bearing failure with water lubricated solutions
Wärtsilä’s water lubricated solutions are approved by all major classification societies and range from complete stern tubes with composite plain bearings to stern tube seals, water quality systems, journals, shaft coating and advanced condition measurement systems.
“The benefit of using a water lubricated solution can be summarised very easily – no oil. With no oil comes no cost of oil, no maintenance of oil, no risk of oil leakage or the fines that come with it,” says Tornberg. “However, the main benefit of opting to replace oil with water is the reduced risk of a bearing failure. An oil lubricated system relies heavily on the performance of the aft seal. In the event of aft seal malfunction, which is the most common reason for stern tube oil spillage and bearing breakdowns, the entire bearing system is in jeopardy. The results can be catastrophic, not only for the seals and bearings, but more importantly for the shaft,” Tornberg explains.
In a water lubricated stern tube system, the water quality system maintains the flows and temperatures inside the stern tube and controls the environment the bearings are functioning in. When you are controlling the operating environment, you can ensure that the bearings will always perform in, or as close as possible, to its optimal conditions.
Vessels operating in the extreme conditions of Polar Regions don’t have to choose oil as their main propeller shaft lubricant due to low water temperatures. This makes water lubricated systems even more attractive.
“The modern water lubricated stern tube systems can be supplied either as open looped or closed looped systems. Selecting a closed looped system for particularly cold environments allows the operator to mix anti-freeze fluids, such as glycol, into the circulating water. This makes it possible to have the benefits of a water lubricated system even in very cold conditions,” Tornberg concludes.