Thread: Question about megayachts, superyachts. Can you change the engine if it goes bad?

What if I just wanted a bigger engine. haha

Originally Posted by waterboy222

Ive never seen one taken out thru the side of a steel hull, if it was large enough to be a steel boat, the motors would be rather large and have the ability to be rebuilt while on-board (not saying they DONT do it, Ive just never seen that before)

Ive seen it done on 3 separate occasions on early 1970s Fedships. I honestly cannot remember the reason behind it, but Im fairly sure that the blocks on these engines would not fit out through the existing access. I also recall it having to be done for the generator on one occasion....

Originally Posted by PBR ME

Ive seen it done on 3 separate occasions on early 1970s Fedships. I honestly cannot remember the reason behind it, but Im fairly sure that the blocks on these engines would not fit out through the existing access. I also recall it having to be done for the generator on one occasion....

Generator I could understand, being that they are typically against the bulkhead and removal of the engines would be first on the list of getting it out of there! But unless the block was cracked, I dont know why they'd want to pull the motor out the side... Steel being much easier to fix than fiberglass, it may make more sense.. I'm not terribly familiar with single steel hulls, I slept through that class, knowing I wouldnt be working in that field....

As I said, it MAY have been the generators on at least one occasion...

Originally Posted by waterboy222

Cruise ship/fleet tankers/ cargo ships are all rebuilt while in motion, they are so short rpm'ed motors that they can rebuild one cylinder at a time while its still under way.

Amazing

YouTube - World's Toughest Fixes - Cruise Ship Engine

Interesting video... They go through the side.. Weight of the engine was equal to the weight of 4 737 boeings...

I'm working on a few projects right now---70' Aluminum Passagemaker, they are building the boat, and then once the customer has made up his mind as to power, they'll just cut the port side of the the hull open and weld it shut when the engine is in.
During the build of a larger, 90' and 141' by the same builder, they left sections of the hull open so that the trades didnt have to go up and down and all through the yacht to get to areas in the hull, or up at the bow.
On one of my customer's yachts, after they did a major refit, a mechanic discovered that the crank in the engine (a 16 cylinder locomotive engine) was bad. They had to jack the engine up, drop the pan, and pull this crank out.... makes me sweat thinking about it...
All of these are built to Lloyds, or DNV standards, so when a panel is properly welded back in, the welds are not dressed or ground down. The fairing compound is built up to the weld, so no compromise in strength.

I always enjoy the tours of the engine rooms, and all of the mechanical goings on...

Originally Posted by Forfend

Where did the resident yacht builder go off to...his name is escaping me at the moment.

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Me you talking about?
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Yes the engines can be replaced without a problem, though not common. Like it was mentioned above, the structure of the deck is designed with space large enough for the engines to be pulled out from. Of course the engine needs to be totally stripped of all accessories before hand cause the space is not all that large.
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Some yachts have the cutout visible, while others laminate everything and makes it invisible (for asthetics). When the time comes, all you have to do is removed the fiberglass deck (or cut out "along the dotted lines"), overhaul the engine and then re-laminate.
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I have come across some yachts that dont have that at all, and we have had to literally chop it to get the the engines.
However, all our designs are out of aluminum so it facilitates this event for the owner, should it arise.
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Heres a pic of an aluminum hull that didn't have the cutouts. Obviously we didn't cut it in half just to get to the engines. We needed to pull the engines out to replace with larger ones because the hull was going to be modified.

Good to see you back, bro!

Thanks, I am glad to be back!!