M/E low load operation

What is the lowest, safe load for the continuous operation of a MAN ES Main Engine?

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Hi @Paraschos.Liadis

Interesting question, especially nowadays, considering fuel prices. As per SL09-511/MTS, MAN indicates the lowest ME Load as 10%. However, it goes without saying that several precautions shall be considered, when the vessel operates at this load range.

To be more specific, engine load up should be minimised, while the following instructions as obtained from SL09-511/MTS should be always adhered to.

Additionally, following shall be taken into consideration:

  1. Avoid operation on the corresponding scavenge pressure where the auxiliary blowers will automatically start/stop. It is preferable, to have the auxiliary blowers activated and turned on manual. Auto start/stops could damage the electric motors of the blowers. Depending on the type of bearings (open or closed type) ship’s crew should frequently grease through grease nipples.
  2. Turbocharger (s) should be regularly cleaned as per makers’ recommendations with nutshells at the frequency set by makers’. Similarly the engine should be loaded up in order to avoid fouling of the Turbocharger.
  3. At first convenient opportunity; scavenge inspection to be carried out and overall assessment of the cylinder condition to be done. Emphasis to be given in proper cleaning of under piston pipe and drain pipes as there is possibility of increased sludge formation, which could lead into high under piston temperatures and subsequently to under-piston space fires.
  4. Main Engine parameters through CoCos to be frequently monitored and specifically the section of the load diagram, in order to verify whether the vessel runs in in light propeller.
  5. Exhaust gas boiler to be frequently cleaned as there is possibility of excessive soot accumulation is noted.
  6. Frequent drain oil analysis with onboard kits (if applicable) to be carried out to evaluate cylinder condition by monitoring Iron content.
  7. In low loads (10-15%) the engine is running below breaking point and as a result Cylinder lubrication is RPM dependent and hence increased cylinder oil consumption will be observed.