For huge cargo vessels that carry millions of litres of oil, thousands of shipping containers, or tens of thousands of tonnes of coal or steel, safety is paramount. These ships must comply with rising safety standards that require time-consuming inspections by surveyors, who in turn risk their own safety by climbing inside massive cargo areas and on scaffolding constructed around ships.
© Fotolia/Sinisa Botas
To help save time and money, and improve the accuracy and quality of these important inspections, an EU-funded research project has developed a fleet of remote-controlled robots that crawl through cargo ships in search of cracks, corrosion and other defects.
Equipped with robotic arms, cameras and magnetic wheels, the robots roll up and down the high, steep walls of ships, looking for defects on the massive steel plates and measuring their thickness with ultrasound. Controlled from a central station using virtual reality techniques, the robots crawl throughout the ship – taking pictures, videos and measurements without the need for human inspectors to go inside the hold or climb up scaffolding.
The projec t , known as MINOAS (Mar ine INspection rObotic Assistant System), holds the potential to make ships safer while also extending their life at sea.
"MINOAS can help ship surveyors by giving them more tools to conduct more thorough inspections", said Alessandro Grasso of the Italian classification society RINA, which is coordinating MINOAS. "As far as we know, this is the only project of its kind in the world."
MINOAS ideally demonstrates how uniting specialists from a variety of different industries throughout Europe can spawn leading-edge innovation while increasing the competitiveness of a critical industry by cutting costs, improving workplace safety for inspectors and lowering environmental risks associated with unsound cargo ships.
Among the four models of MINOAS robots is the "Magnet Crawler", a two-wheeled, batterypowered device with a miniature video camera, two motors and a handle-shaped elastic tail. Weighing less than a kilogram, it climbs walls at a half-metre per second and transmits videos and images to human inspectors carrying handheld receivers.
In a demonstration of their teamwork, the robots can conduct inspections in pairs – the first using a brush to clear away rust and dirt so that the second robot can use its ultrasonic device to measure the thickness of the wall. The robots' advanced locomotion abilities enable them to operate in every compartment of ships.
The robots offer other advantages over human inspectors. "With the robots, we expect to obtain more data – quicker ", said Grasso, whose organisation is charged with, among other responsibilities, certifying the safety and environmental worthiness of ships. "By having more detailed data, we can make more accurate comparisons with previous inspections, to see if there have been any changes that need to be addressed."
This last point carries extra importance. By closely monitoring cracks, weak spots and other types of deterioration over time, ship owners will better be able to estimate future damage and the costs to repair it.
Grasso said MINOAS has received great interest at technology expos, and the project team expects the robots to reach the commercial market in the foreseeable future.