3.4 Lubricating oil system
Regular maintenance of a vessel's lubrication system is vital; this includes cleaning filters, inspecting piping and monitoring the lubricant levels in reservoirs. Selecting the right product for each component and complying with the manufacturer’s specifications and recommendations are paramount, as using unsuitable products can lead to medium and long term problems. The lubrication system must comply with international standards and be suitable for maritime use, as ships operate in different conditions from land and industrial vehicles. It must also be resistant to extreme environmental conditions, such as humidity and salt water. Products supplied to the ship must be resistant to rust and corrosion and have high thermal and mechanical stability. How a vessel’s machinery is lubricated has a decisive impact on its durability and leads to considerable savings in maintenance and new parts.
There are numerous types of lubrication systems, but in general they fall into two categories: centralised and decentralised lubrication systems. The main difference between them is the way in which oil is distributed around the ship’s critical components. In centralised systems,the lubricant is pumped from a central source through pipes to reach all components. In decentralised systems, each component has its own lubrication source and is therefore not dependent on a single service. As to which of the two systems is better, it depends on the specific needs of the ship and its intended use. Centralised systems are easier to maintain, as there is only one pump and one set of pipes that need to be maintained. However, they may be less flexible in case of failures or changes in vessel occupancy. Decentralised systems, meanwhile, offer greater control over the lubrication of individual components, which can be beneficial in labour-intensive or harsh environments; however, they require greater supervision.
In both systems, it is important to ensure that the oil supplied is of the right type for the specific equipment and that it is maintained at the correct pressure, flow and temperature conditions. In a centralised system, the lubricant is directed to friction points by a lubrication pump via specific ducts. This is suitable for large vessels with a large number of lubrication locations. Centralised systems are a way to ensure that critical ship components, such as engines, transmissions and bearings, are continuously lubricated. A central lubrication pump is responsible for supplying lubricant to friction points and recirculating it properly through the mechanical systems, preventing them from serious deterioration.
Decentralised systems on ships are those in which each critical component has its own source of lubrication, rather than relying on a central pump for lubricant distribution. Instead of a pipeline, this system has several individual sources and conduits for each component. However, it requires greater supervision to ensure that each component is working properly, as well as an organised schedule to ensure that each component is receiving the lubrication it needs.