Bakker Sliedrecht, the Netherlands based provider of electrical and automation solutions for the marine industry, is starting research to determine whether biodegradable oil can be used in submersible motors.
Dutch dredging giant Van Oord is among Bakker Sliedrecht's submersible motor customers and, if applicable, would like to use this type of oil on more of its vessels.Regulations for the use of oil are becoming more strict because leaks can have major consequences for the environment.
Bakker Sliedrecht, together with partner INDAR, has developed its own electric submersible motor which allows dredgers to operate at depths to 250m despite harsh conditions. Some 200 dredgers have already been equipped with this type of motor, including some operated by Van Oord. Such motors can contain up to 1,000 litres of oil for cooling and balancing pressure levels when working at depth.
"Van Oord wants to know whether biodegradable oil can also be used in the submersible motors that we have supplied and will supply in the future, say Wim Verlek and Marcel Bakker of Bakker Sliedrecht. "They already have positive experiences with this in other underwater applications.
"We have never had a major leak with our submersible motors, where correct maintenance of the motor is an important aspect. You want to prevent environmental damage in vulnerable areas. The risk of such a catastrophe is very small but it can never be ruled out."
The research will be carried out in three steps. First, the electrical and physical properties of the biodegradable oil are examined in the laboratory and compared with the current oil. They must not differ too much from each other and the properties must remain within a certain range. In the next phase, various parts of the underwater motor are exposed to the new oil. The samples of windings, internal coating, cable insulation and other materials are immersed for several months in biodegradable oil that is heated to operating temperature. It is then determined whether the deviation is acceptable. In the third phase, the rubber O-rings and Simmerings are checked to determine if they are resistant to the new oil. If not, they can possibly be replaced by a different type of rubber.
If all tests are positive, a pilot will be conducted in which biodegradable oil is actually used in the submerged motor of a trailing suction hopper dredger.
By Larz Bourne