The trend leans towards larger vessels operated by less crew. Operating large ships with a relatively small crew puts focus on how to use person-hours more effectively. We can learn from Condition-Based Maintenance (CBM) strategies implemented by the land-based industry exposed to international competition and adopt this way of working in the maritime industry. A big part of the maintenance work onboard vessels is, in fact, unnecessary and a product of tradition and previous demands by the class.
The combination of unskilled labour and inspections by classification societies of machines stripped for visual inspections have contributed to the extreme workload in many machine rooms. The redundant machines are installed for safety but are mainly used to compensate for the problems this maintenance approach gives.
CBM are routine measurements and inspections carried out by a selected crew trained to evaluate the results and determine possible corrective maintenance. The redundant equipment is included in the inspection to ensure that they work when needed for safety reasons. The CM software can be connected to the maintenance management system to issue work orders and get the action reported back into the system automatically. The machines are prepared with adapters and transducers to ensure quality readings. Critical equipment like turbochargers can be equipped with online systems for extra protection.
The condition information is used to get an early warning for replacing parts before failure. The readings can also be used for class inspection as an alternative to opening up machines for inspections.
CBM increases reliability and requires fewer person-hours by eliminating unnecessary maintenance caused by time-based inspections and the extra work that catastrophic failures give. The work can be planned and give the crew stable working hours. In addition, there is a reduction in spare part consumption, allowing a smaller stock and making the number crunchers happy.
