“We have saved the cost of an expensive electrical motor.”
Peter Hansen, Technical Director, Tide Sjø AS
Ferry operator Tide Sjø AS decided to introduce condition-based maintenance (CBM) on four of its ferries to improve the reliability of machinery, extend inspection intervals and reduce costs of maintenance. They turned to SKF.
Tide Sjø AS is one of the biggest passenger and car ferry operators in Norway. The company has been in operation since 1880 and today runs 50 car ferries and 35 passenger ships, transporting some 12,5 million passengers every year.
With so many people reliant on its services, the company needs to meet strict timetables and key connections to buses and other transport that also serve its traffic area. Consequently, reliability and regularity of services are vital, and maintenance is a key factor for success.
Until 2008, maintenance at Tide Sjø was mostly planned by number of operating hours. This time-based maintenance approach is typical and has been adopted by ship owners and operators in the marine industry for many years. However, many companies are waking up to the opportunities afforded by condition-based maintenance (CBM) to extend inspection intervals and reduce costs of maintenance.
In the CBM program developed for Tide Sjø, SKF engineers board the particular vessel at an agreed frequency. On board, they collect data from critical machinery such as thrusters, generators, gears and support bearings.
The data is then uploaded in an SKF @ptitude Analyst database, located in-house at SKF to ensure that the analyzing software is kept up to date, and a report is generated and sent to the customer. In essence, SKF carries out monitoring of rotating equipment, such as electrical machinery, in particular generator sets and propulsion engines at intervals of one to three months.
Peter Hansen, technical director at Tide Sjø, explains that these are comprehensive reports that come with a narrative that highlights results, machine evaluations, trends and proposed corrective actions, if needed. “We react speedily,” he says. “If something is really urgent, SKF calls us and advises us how to apply the appropriate corrective actions.”
Since the CBM program was introduced in 2008, Tide Sjø has experienced fewer breakdowns. Monitoring and vibration data analysis on the Tide Sjø ferry, Folgefonn, for example, highlighted problems with the shaft support bearings in two thrusters.
“After implementing the recommendations stated in the SKF report, we have saved the cost of an expensive electrical motor,” says Hansen. “It is too early to document savings from better maintenance schedules, but if we can extend the services to reschedule thruster overhauls, the savings will be very good.”
Overall, the company has been able to reduce downtime by detecting incipient equipment problems at a very early stage. In addition, the company has learnt how to better overcome issues that decrease vessel availability.
“SKF provides good, self-supported services to our engineers on shore and also to our on-board crews,” concludes Hansen.
Tide Sjø AS challenged us. Now it’s your turn.