On Sun, 22 Mar 2020 19:05:58 +0000, Richard Smith
wrote:

Hello all

You are a group with a lot of technical interests and knowledge.

Boats - for a vessel with a single screw and about 500HP, or a
twin-screw vessel with about 1000HP (500HP each engine and gearbox
drive)...

Some have a/two straight-6cylinder engine(s) like the Cummins K19(M?)

Some have a/two Caterpillar 3412 V12 engine(s)

Why?

The straight-6 would be - cheaper? simpler?
The V12 would be - ... ?

Thanks in advance is you can help take this curiousity to its
end-point.

Regards,
Rich S

I'm no naval architect, and only have outboards. Nothing near that
size. I would guess the V-12's advantage would be more compact size
for boat design, as well as possibly higher rpm, different vibration
qualities for easier soundproofing in high end applications. The
sixes would probably be easier to maintain, not just because of less
parts, but because the package shape would lend itself to better
access in the engine room.

Just thinking on the keyboard here.

Pete Keillor