Service Letter SL09-511/MTS MAN Diesel

Dear Sirs

Our Service Letter SL08-501 has triggered an interest for continuousrunning of MAN B&W engines below 40% engine load. This service let-ter outlines our recommendation for MC/MC-C and ME/ME-C engineoperation in the load areal0o/oIo 40% engine load. ln this load area,ME/ME-C engine performance parameters will be superior to those ofthe MC/MC-C engines, thanks to the hydraulically actuated fuel injec-tion and variable exhaust valve timing.

MAN B&W two-stroke engines are designed for continuous operation at'100% engine load, but with the appropriate precautions, safe and reli-able continuous engine operation down to 10% engine load is possible.

However, more frequent inspections, and appropriate reaction to these,must be accepted by operators, as not one recommendation or solu-tion is applicable to all two-stroke propulsion plants.

Basic requirements:. Slide-type fuel valves. Monitoring of exhaust gas ways for fouling.

Furthermore, electronically controlled cylinder lubrication is advisable.

An important factor during low-load operation is that the operators givesufficient attention to the condition of engine, turbocharger and exhaustgas boiler. For further advice and information, operators are welcometo contact MAN Diesel in Copenhagen by e-mail at Primeserv-cph@mandiesel.com.

Yours faithfully

Vice President, Engineering

Encl.

Action code; WHEN CONVENIENT

Low Load Operation10Yolo 40% Engine Load

SLOg-511/MTSMay 2009

GoncernsOwners and operators of MAN B&Wtwo-stroke marine diesel engines.Type: MC/MC-C and ME/ME-C

SummaryLong-term low load operation down to10% engine load is generally possiblewith appropriate precautions and withoutmajor modilcations.For application with 3-4 turbochargers,MAN Diesel recommends installation of aturbocharger cut-out system.

Senior Manage Engineering

ProductonTglholmsgade 352450 Copenhagen SVDenmarl