How do they do that then?

[Nasher]

All

Yesterday evening ‘Into the Blue’ and myself were talking about various things boat related, and came up with a question neither of us knew the answer to.
Much to Mrs Nashers delight I should add.

Having been to the Southampton boat show, we were discussing the bigger motor cruisers and super yachts, and to cut a long story short we’d like to know how they get the huge engines out, and replacement back in, if something goes wrong enough to require a replacement.

On smaller motor cruisers I’ve seen the deck is removable for access, but on many bigger boats the engines are buried deep inside the boat under cabins and below decks that really don’t look removable, or are part of the structural integrity of the boat.

Is anybody on here rich enough to have first hand knowledge of how these things happen?

I’m sure it’s the same on commercial boats as well, but maybe there isn’t so much of an issue slicing up the steel deck and welding a new one in when the work is over.

Perhaps the engines break down into smaller pieces, and would be built up in place.

I’m just concerned that when I place an order on the £10M Sunseeker I’m thinking of buying I will want the option of putting bigger engines in when I’m bored with its pathetically low fuel consumption.

Ta

Nasher.

[Tim M]

I don't know the answer, but I'm guessing the engines must "break down" somewhat to allow them to be removed, likewise various bits of boat must come off. The newer Gosport ferries have sections that unbolt from the deck and roof so the engines can be lowered in and out. When Mike Perhams Open 50 came back in to Portsmouth a couple of weeks ago they had to take the generator out. Its very crampt inside that boat; they had to take a lot of parts of the gennie to get it through the hatch.

PS. Can I borrow the Sunseeker when you get it and park it in Gunwharf one Friday night? I've been told a bigger boat will give me more success with the ladies.

[badbaws]

On a ship we just gas axe a panel of steel to make an access hole, but on a nice sunseeker who knows!

[bedajim]

Disk cutter to the bottom

[bedajim]

Originally Posted by Tim M

I've been told a bigger boat will give me more success with the ladies.

No not a bigger boat

[codprawn]

On many of the smaller Sunseekers and Princesses etc the engines are in the tender garage area. They are often reached through large hatches in the rear cockpit.

On the larger boats I assume the engines never reallly need to be moved. Cranks - liners - individual heads etc can all be replaced in situ. It almost never happen a block goes.

[bedajim]

Originally Posted by codprawn

On many of the smaller Sunseekers and Princesses etc the engines are in the tender garage area. They are often reached through large hatches in the rear cockpit.

On the larger boats I assume the engines never reallly need to be moved. Cranks - liners - individual heads etc can all be replaced in situ. It almost never happen a block goes.

Well if there's a rule etc, further down they explain about the gearbox removal too

http://www.fairlineownersclub.com/fo...opic.php?p=195

[codprawn]

Originally Posted by bedajim

Well if there's a rule etc, further down they explain about the gearbox removal too

http://www.fairlineownersclub.com/fo...opic.php?p=195

Nah I meant much bigger - modern engines over say 1000hp. Usually pretty modular in construction.

Then again modern engines are nowhere near as good as the old slow revving diesels - old B+W - Kelvin - Lister Blackstones etc etc. Often would weigh about 8 tons for 300hp but they were huge and you could take down pistons while it was still running as you can on the huge ship engines now.

[Leapy]

Originally Posted by Nasher

we’d like to know how they get the huge engines out, and replacement back in

They get the gyni in...

[SeaSkills]

When I needed to replace a fuel tank on my 40 footer, they suggested cutting a panel out of the hull (and promised they would make it "good as new").

I didn't fancy that much, so we worked on Plan B - cut the old tank into small pieces to get it out, and then instal several smaller tanks, stacked up and linked together

[bedajim]

Originally Posted by codprawn

Nah I meant much bigger - modern engines over say 1000hp. Usually pretty modular in construction.

Then again modern engines are nowhere near as good as the old slow revving diesels - old B+W - Kelvin - Lister Blackstones etc etc. Often would weigh about 8 tons for 300hp but they were huge and you could take down pistons while it was still running as you can on the huge ship engines now.

These boys will know, I've been around the place "big engines"

http://www.dfcspares.com/remanufactured.htm

[Nasher]

Thanks Guys, looks like there is no easy answer as we suspected.

Nasher.

[chewy]

Seems on large steel vessels you dry dock them and cut a big hole in it!

[G.Mac]

Yup anything big and steel, they just cut a big old hole ion the side and weld it up afterward

[fraztiree]

No No the real answer is if the engine goes they just go and buy a new boat!

[Bigmuz7]

Originally Posted by G.Mac

Yup anything big and steel, they just cut a big old hole ion the side and weld it up afterward

Which is fine on a trawler but I think your Arab Sheik might be annoyed if you attacked his GRP Mega yacht this way

Who Knows Nasher .. maybe when they are that big .. they've got some metal in 'em ?

[tonymac]

Originally Posted by fraztiree

No No the real answer is if the engine goes they just go and buy a new boat!

Best answer yet!!

[SeanSunseeker]

The larger Sunseekers where the engines aren't located under the aft deck which can be removed for access there are access hatches through the deck levels. Means some furniture has to be removed but even on the 100ft plus you could remove both engines after a couples of days work.

[Nasher]

Originally Posted by SeanSunseeker

The larger Sunseekers where the engines aren't located under the aft deck which can be removed for access there are access hatches through the deck levels. Means some furniture has to be removed but even on the 100ft plus you could remove both engines after a couples of days work.

Ah ha. Thank you very much

Nasher

[Ricky]

Originally Posted by Bigmuz7

Which is fine on a trawler but I think your Arab Sheik might be annoyed if you attacked his GRP Mega yacht this way

Who Knows Nasher .. maybe when they are that big .. they've got some metal in 'em ?

When you reach the size of super/mega/gigayachts the vessel is steel, actually classified as a commercial cargo (12 or less guests + crew) or passenger vessel (12+ guests) depending on the build standards. To smooth out the imperfections the hull is coated with a roughly 5mm thick layer of levelling compound and finally a layer of gloss white paint is sprayed on.

The vessel is built around the engines, repairs are generally performed onboard and cranes fitted in the Engine Room for overhauls and repairs.

Should it reach the point that the engine needs removing, as has been said above, the vessel is drydocked and an opening cut into the side. The engine will be removed/replaced, then the opening is rewelded and work commences on restoring the paint job. The paint job may cost $1million+ as it may require the entire vessel to be repainted to colour match. The drying times and conditions for the paint means it can take 3 or 4 months to complete the paint job, either in a paint shed or scaffolding built over the vessel, dehudifiers and heaters installed, dust removed from the air etc.

Hope this explains!