Marine transportation is estimated to account for one third of global oil pollution. Furthermore a global predicted increase in offshore exploration, production and transportation of oil within sensitive marine areas has increased the risk of pollution. Oil spills from vessels in particular are a serious threat to the marine environment.
Risks of pollution can be offset by increased surveillance and more efficient clean-up operations. Additionally, spills in 'special areas' defined by international conventions are theoretically given special protection through targeted legislation. However, this is hard to enforce because of a lack of appropriate technology; existing methods, such as air surveillance, are prohibitively expensive.
A system of sensors was developed in a former LIFE project - OSIS (Oil Spill Identification System). This system involves permanently mounted sensors communicating with the shore via a satellite link. The system works well with offshore structures such as oil platforms but cannot be directly applied on moving ships.
This project aimed to develop the OSIS technology, creating a sensor and transmission system suited to the special conditions relating to ship transport. It particularly targeted finding the best ways of measuring oil-spill extent and quantity in a three-dimensional environment from a moving vessel, and effective data-transmission from a ship constantly changing its geographic position.
Overall, the project sought to reduce oil pollution through providing a better monitoring and control system, which could also enable stricter legislation and enforcement. An effective system would enable wider ratification of environmental legislation and conventions relating to the designation of marine 'special areas'.
The project successfully developed the OSIS Sensor Pack, which provides a low-cost, highly reliable and efficient method for on-spot monitoring of oil pollution. It developed a system based on data transmission and sensors which can be used on moving vessels.
The project designed an integrated data-acquisition system based on: electromagnetic sensors with different frequencies able to detect as little as 0.02 mm of oil on the water surface; a pivoted support - gimbal - allowing the rotation of the sensor about a single axis to enable measurements from a moving vessel; and embedded software.
The beneficiary completed a comprehensive performance specification and drew up 3-D design models of the prototype sensor. It was designed to compensate for movement of both the water surface and the vessel –on two planes - by up to 10 degrees. Extensive tests of the wave compensation module were conducted, demonstrating that the user was able to control the sensor positions exactly, thus enabling precise measurements on a moving vessel.
The beneficiary developed a complementary integrated system - comprising both hardware and software - to enable real-time data transfer from the vessels to an on-shore central server. Low-cost transmission options, such as the UAIS transponder system, can be used most of the time, whilst more expensive transferral of compressed data via satellite is possible when an oil spill is identified. Cryptography and data protection techniques were implemented.
Following design review, the transmitter was transferred to a separate unit to improve its range and minimise the size of the sensor. Further practical tests, including via controlled spills of margarine and rape seed oil, led to subsequent minor design modifications.
The project dealt with issues in integrating sensor data into ship-bridge electronics to allow for data analysis and a presentation system according to the needs of the end user. Database coding and a decision support system were also designed. Together with the sensor network, these provided an online monitoring system allowing automated oil-spill detection.
The market for commercialisation of the sensor is rapidly developing and the project already heavily involved the Danish navy in performance specifications, design and testing. To reach other groups, OSIS produced a demonstration DVD and leaflet and presented the project at various professional events. This state-of-the-art technology is expected to become an essential part of maritime equipment, thus significantly contributing to reducing pollution from oil spills.