A curiosity question.

[enginesrus]

Youtube shows some video's of various recip marine engines undergoing repairs, like medium size engine having a crankshaft replacement, and some larger 2 strokes having piston changes etc. Does anyone know what these sort of repairs actually cost? It would also be interesting to know the approximate costs of the various size marine engines? Do some repairs actually end up costing more than what a replacement engine would cost?

 

[boo1]

cheaper then cutting a hole in the hull to remove a complete engine?

 

[TugboatEng]

It's extraordinarily rare to have to do a repair like this so many of us are unfamiliar with the costs. Add to whatever the part costs the fact that it takes an extraordinary amount of labor to get it to where it is supposed to be in the engine room. I work with smaller engines but we're paying, at this moment, $300k USD in labor to move two 9 ton engines to their beds in a fairly simple operation.

I don't have any large slow speed experience but most parts get refurbished and not replaced. It was the cylinder liners that were expensive at some $100k a piece but that was also 20 years ago. These ships are built around performing the service so labor is minimal to get the parts in and out.

 

[SandCounter]

I saw a crank shaft replaced on two installed engines. The issue was more about the time than the cost. The engines took about a year and a half to manufacture, then cracked the shafts within the first 15 minutes of dock-side trials. It was better for time to unbolt the pans, strengthen the overhead, and lift the blocks to install new shafts than to cut 2x decks and pull the engines out and replace them. These were 4-stroke 6,000 hp,1000 RPM. Rough order of magnitude $500K per engine.

I used to count sand. Now I don't count at all.

 

[IRstuff]

The bottom line issue, as alluded to by the other posters, is that marine engines are essentially built-in on a ship, buried deep in the bowels. Repair, and even replacement, has to be done in-situ, and likely done piecemeal.

Just imagine how you would fix your car's engine if the car was placed in a small shipping container and sealed inside with only the small roof hatch as access.

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[enginesrus]

Crankshafts cracked in 15 minutes of run time? So how come the replacements didn't do the same? I guess the manufacture never tested them on a dyno? 6K hp is small stuff when talking marine engines.

 

[BUGGAR]

These repairs are seldom done because these ships must run full time to return their investment. They are not designed for "engine swaps". They either produce or they are scrapped. Look at all the scrapped ships. Shipping containers are also designed to be semi-disposable (economically disposable?).