Conditioned based maintenance

Hello everybody!
We see that the concept of “condition based maintenance” is becoming increasingly popular among oil majors. Can you provide a few examples of conditioned based maintenance implemented on oil tankers and gas carriers?


SL07-483.pdf (1.4 MB)

For Main engine, I am attaching MAN service letter SL207-483/HRR for condition based piston ovhl for ME and MC engines(Containers, bulkers and other vsls with similar trade pattern) : Longer ovhl intervals can be obtained via regular scavenge inspections.

For ER pumps, some tanker companies have applied CBO by performing vibration analysis. Unfortunately I am not aware of the exact procedure.


Condition based maintenance is maintenance performed according to the condition of the equipment and does not follow a standard schedule similarly to the “planned” maintenance"
@AngelikiK has a valid point regarding M/E scavenge space inspections. This is the most “traditional” method of conditioned based maintenance. I would add that during M/E scavenge space inspections the thickness of the cermet (ceramic-metallic) coating must be measured and the piston should be overhauled when the thickness of the cermet coating drops below a certain value. This is critical for engines running of low Sulphur fuels as well as for large bore engines (80 and above).
Other examples of conditioned based maintenance in oil tankers are the following:

  1. Frequent lub oil analyses by external laboratories:
  • Every 3 Months (+1 month): Main Engine, Diesel Generators 1,2,3, Stern Tube,
  • Every 6 Months (+ 1 month): Steering Gear 1,2, and Deck Machinery forward, aft.
  • Every 12 Months (+1month): Cargo Oil Pumps Turbines 1,2,3, Hose handling cranes (P+S), Provision cranes (P+S) Valve Remote Control System, Emergency Diesel Generator.
  1. Vibration and infrared thermography for rotating machinery and electric motors.
    These measurements are to be carried out on motors, pumps and fans by specialists, on regular intervals but at least every 5 years (before every docking). A report is produced and the responsible superintendent takes the necessary actions,
  2. Bearing wear monitoring systems for Main Engine: The bearing wear monitoring systems provide a continuous and contactless measurement of the wear status of the engine bearings. The bearing wear monitoring systems are usually equipped with water in oil sensors that alert the operator in cases of high water content in the M/E system oil.
  3. Performance monitoring of M/E and Diesel Generators. The performance / balance of two-stroke and four-stroke internal combustion engines onboard the ships is evaluated by the use of pressure monitoring sensors (Pmax, Pcomp, Pi). For example, in MAN ES engines the MAN ES PMI provides real time information on the Main Engine pressures and can automatically self-adjust its balance. Real time performance monitoring tools such as the MAN ES CEON platform are becoming popular as well.