Just 2 per cent of the shipping industry has fully adopted condition based maintenance (CBM) strategies despite the cost and reliability benefits it brings. CBM entails the development of a maintenance strategy based on the monitoring of key equipment and systems on ships. If it is done correctly, ship operators and managers can achieve cost efficiencies and increased vessel uptime, and reduce the risk of system failures.
Despite the potential benefits, few shipowners are willing to invest in a CBM programme, which would involve the installation of sensors, the deployment of suitable software and the retraining of onshore managers and crew. According to Kuba Szymanski, secretary general of shipmanagement trade association InterManager, much more should be done to educate shipowners about the investment benefits and payback time. “Ninety eight per cent of the shipping industry is not ready to invest in CBM,” he said. “As an industry we need to find ways to invest in CBM and set standards, as only 2 per cent of the industry are doing this.” He said companies should produce business cases for investing in the technology to achieve the cost benefits quickly.
At the recent Condition Based Maintenance Conference organised by the Institute of Marine Engineering, Science & Technology (IMarEST), shipping company engineers and technical officers outlined the cost benefits. James Fisher & Sons has reduced costs and downtime by introducing condition monitoring on tankers. Martin Briddon, an engineering manager with subsidiary James Fisher Mimic explained how installing a £15,000 (US$21,600) condition monitoring system could save the company 10 times that amount. He told delegates at the conference that a lube oil pump failure could cost £57,000 to repair, but this could take three days, leading to off-hire losses of £90,000 and other costs such as management time and increased insurance premiums.
James Fisher is using one of its tankers as part of a UK Government-funded research project. Mr Briddon said this involves monitoring energy consumption and power from the diesel-electric system, as well as monitoring shaft alignment, system vibrations and weather. “We are monitoring energy consumption and we can predict failures before they happen,” he said.
Despite the benefits, ship operators find it difficult to put the business case to managers that hold the purse strings. Mr Briddon advised that the best way to begin implementing CBM is to start with a pilot project on machinery that causes 80 per cent of problems and failures. He added that cruise ship operator Carnival Cruise Line made cost and time savings by implementing CBM on its ships. “Carnival saved 200,000 man-hours across the fleet as a result of reduced maintenance on heat exchangers over two years when it used CBM. This shows CBM can lead to early repairs, less damage to machinery, better performance and lower costs.”
Shipowner Österreichischer Lloyd Shipping has implemented condition monitoring on some of its vessels. Chief operating officer Aleksander Legowski said the company monitors engines, lube oil and oily water. “We monitor engines to predict failures and can investigate problems. Our fleet managers will analyse data and send it to service providers,” he said.
Accommodation vessel and rig owner Prosafe is implementing a CBM programme across its fleet, starting with its newbuildings Safe Zephyrus, Safe Notos and Safe Eurus. Technical asset integrity manager Syed Ahmed said CBM should reduce unnecessary maintenance and overhauls and lower operational expenditure. “On our new vessels we have long-term charters, so we can streamline condition monitoring, assessment surveys, training, lubricant management and reporting,” he explained. Prosafe has service agreements with the major suppliers of equipment to conduct CBM.
Siemens will provide lifecycle management of the six azimuth thrusters on the vessels and ABB will service the variable frequency drives. Wärtsilä will provide condition based maintenance services on the six main engines and SKF will provide vibration monitoring services. Data will also be recorded from the two Liebherr cranes on these accommodation vessels. “Data is collected on board and sent over satellite connections to the suppliers and manufacturers and to our main offices,” said Mr Ahmed. “We have implemented mooring analysis, structural integrity and critical spares management.”
The monitoring could be extended to the hull of the vessels. “For structural integrity management we have DNV GL fatigue analysis and will install sensors for hull monitoring,” he added. “With regard to condition monitoring for asset integrity and engineering, I am trying to streamline this for existing vessels as well as for newbuildings in order to achieve a return on investment and cost optimisation, and to avoid unnecessary maintenance costs.”
Mr Ahmed continued: “To make the system effective, our three biggest challenges are trying to structure the condition based maintenance methodology, the analysis, and creating a culture so that people can understand the link between condition based maintenance and remote diagnostics and system management.”
Offshore engineering group McDermott International has implemented CBM across its fleet after suffering a US$2 million loss as a result of a gearbox failure two years ago. Global marine fleet manager David Baker said that the failure shut down one of McDermott’s offshore construction derrick barges for more than 30 days, which meant it had to go off hire. He said CBM could have prevented the failure and the loss.
Norbulk Shipping has considered using CBM for various onboard systems on its tankers. Marine engineer Jamal Ghotbzadeh said that CBM should prevent shipping accidents and reduce downtime. It can also reduce maintenance costs, he explained. “CBM should prevent unnecessary refits and overhauls. A planned maintenance system may call for maintenance on a piece of equipment, but the CBM would recommend leaving it alone.”
He continued: “The aim is to find the right time to conduct maintenance by gaining prior warning from the equipment before failure occurs. CBM can improve reliability. For example, bearing wear can be reduced. With CBM we can predict what problems are coming, improve performance and minimise downtime.” He said vessel monitoring can include vibration, oil, thermal and ultrasound analysis, as well as engine performance tests.
Offshore support vessel (OSV) owner DOF Group is using VSAT and fleet management software to monitor ship systems and manage maintenance programmes on its fleet of 62 vessels. DOF collects data from various sensors on its OSVs and sends this via VSAT and satellite networks to onshore centres. The data is fed into the company’s database, which uses Tero Marine’s TM Master fleet management software, for further analysis. Information is then sent back to the chief engineers on the vessels, who can conduct preventative maintenance on ship machinery, said DOF manager for maintenance Jørgen Sjo Samuelsen.
“We conduct planned maintenance using the TM Master centralised system and data sent from the vessel to our offices,” he explained. “We also use condition monitoring for preventative maintenance. We measure machinery parameters, such as temperature, vibration and alignment, to find failures before machinery breaks down.”
He said that vibration monitoring is conducted on propulsion systems, thrusters, generators, and azimuthing propellers. “On eight vessels we have online monitoring, to detect damage to equipment at an early stage to prevent breakdowns. Electro-mechanical company Karsten Moholt created an online portal for these vessel. Data is sent to the ships and the technical offices onshore, so we can create reports and detect issues,” Mr Samuelsen added.