Management of a Low Speed Diesel

The steam side had their thread. In general there’s a lot going on in the E/R of a diesel ship. Some of the knowledge and expertise is shifted in time, that is not it’s not all minute by minute operation.

For example I talked to four different chief engineers about this issue.

This is the point here. The area that is the intersection.



The critical revs are normally stated on a plate alongside the bridge control and engine room control.

For those ships critical speed was between slow and half ahead. IIRC it was 38 to 43 rpm. Normally the automation moves the engine through the critical range quickly enough it only causes a slight, momentary shimmy. If the rpm hangs there the vibrations become very noticeable.

The workaround is go to full ahead then back to half. The fix was to adjust or replace the throttle linkage.


90% fuel conditioning and/or dealing with the resulting waste oil and water mixes from the fuel conditioning or engine.

10% following procedures to repetitively and boringly change overpriced but ill fitting parts and then figuring out why the procedures are wrong and there’s 50 ways to do it better.

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Yeah it’s not the most fun job sometimes.

Modern slow speeds are much more fuel efficient than steam ships, but they also wear out more parts.

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One thing I wonder is, does it make it harder to go ashore in your career. These engines are basically only found at sea, it’s not like the days where a ship and power plant had much in common. A giant two stroke is about as relevant as a mate’s job to anything else.

I think it makes transitioning to a shoreside steam plant more difficult, but it’s not like we’re spending all of our time on main engine maintenance tasks that don’t cross-over to other machinery. Knowing how to work with tools, read piping/electrical diagrams, troubleshoot auxiliary equipment, and so on are all pretty much the same regardless of your prime mover.

That being said, I’d absolutely love it if we could bring steam back.

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It seems so long ago that engineers in the company I worked for struggled to get a job on the only two motor tankers the company owned so they could get a motor endorsement.
When I look back the number of spare parts we required was a fraction of the parts used in a low speed diesel. 5 tonne liners, cylinder heads and pistons being loaded and shore side fitters working in the short turnaround times of a box boat while ship staff repaired a bit of brickwork on the steamer.
On one vessel in for a ten year survey they erected a plastic tent over the turbine and dressed like surgeons they removed the turbine shroud, took measurements, and then announced there is nothing to see here and boxed it back up.

Far from it.

There are a very large number of slow speed two strokes installed in shoreside power plants all over the globe and the market is expected to continue to grow.

MAN and Wartsila are big players in that market. The newer medium speed engines are gaining a large share because of emissions and multi-fuel capabilities but the installed base of slow speed two strokes is very large.


Large steam and now gas turbine (combine cycle) still dominates the shore-side power industry. But a valve is a valve, and a pump is a pump. Few, if any ship engineers ever cracked open the steam turbine or associated hardware. But, few plant operators ever do the same shoreside.

Some islands have slow-speed diesel engines. Guam had 4 ~40MW units, until two uhmmm went boom.

I wish the US had ever gotten nuclear costs and permitting under control. Clean and green energy, but high wage blue collar heavy industry, but also the midcentury slide rule World of Tomorrow thing going on. It scratches a lot of itches, so to speak.

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