Why the heck are boats so loud??

Discussion in 'Boat Design' started by eponodyne, Oct 6, 2007.

  1. safewalrus
    Joined: Feb 2005
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    safewalrus Ancient Marriner

    Probably don't bother for a couple of reasons - they know that americans link loud with power and get off on that (well it's the only explanation I can think of!) and they know that everyone else is making 'em loud and noise supression costs money, so why spnd it when you don't have too! And still charge the same price for the job!
  2. charmc
    Joined: Jan 2007
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    Location: FL, USA

    charmc Senior Member

    Not all Americans like the loud boats. Some enterprising soul is making a ton of money selling a small electronic gadget that can be amed like a handgun and set to make sounds like a machine gun, laser strike, missile launch, etc. Makes a nice fantasy of what one would like to do to the loudness louts. :D
  3. eponodyne
    Joined: Aug 2007
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    eponodyne Senior Member

    Ike said that living on a boat, you are essentially inside a drum. That's the part that makes it so annoying to me, because the problem could so easily have been solved during refit by bolting strips or pads of lead to the bulkheads and overheads, to move their natural resonance out of the range of vibration generated by the engines and gensets.

    I can understand not wanting to get into the complexity of a water-lift muffler on a vertical exhaust; but this is what is known as a "shotgun" boat, with a telescoping wheelhouse to allow it passage under fixed-height bridges. So why a vertical exhaust at all? Why not run the exhausts out through the rudder room, out the aft end of the boat? It'd buy acres of deck space, too!

    The engines could be spring-mounted. Yeah, the mounts cost more than simple girder stock cut and welded into place. But again, measured against the cost of the whole, a pretty insignificant accounting.

    I know that KaMeWa has equipped a couple of towboats with jet drives, and I'd like to think that this might become more common. Probably won't, though, with the combination of high-speed Diesels, Twin Disc gears, packing glands, and NiBrAl wheels in Kort nozzles being such an effective and proven technology. Although these boats work in narrow channels and are almost always sniffin' bottom, maybe jet drives would offer some advantages in ship handling.

    By the bye, I've got to say that the boat drivers on the Illinois River and the Chicago Sanitary and Ship Canal do just a bang-up job. The ship handling is absolutely phenomenal: Shoving a tow of barges five long and two wide (1000' by 70'), always dealing with bank cushion, bottom suction, wind and current... collisions and allisions almost never occur, although getting men out on the head of the tow to continually radio in relative course, bearing, speed and distance to obstacles and hazards to navigation certainly play a part in that. Perhaps the oddest thing that occurs on a daily basis is making locks; getting the tow most of the way in ever so slowly, then pulling back on the throttles and having the tow speed up :eek: !

    What has happened, of course, is that in a confined space, physics dictate that water pulled from behind the boat is thrust forward into the barges ahead of the boat and rebounds, pulling water from under and around the tow out with it then the whole thing can go all to aitch ee double toothpicks in a hurry and the deckhand with the hawser had better be quick and sharp to get a line on a timberhead to stop it before it crashes into the lock gates. Which is where I come in. Which is why I need my sleep.

  4. Ike
    Joined: Apr 2006
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    Ike Senior Member

    I just gave the reason why they are noisy. I didn't say it can't be fixed, because it can. Every IBEX I have been to (I've been going since 95) has had at least one seminar on sound deadening. There are always booths there hawking systems to kill all that noise. It's definitely possible and some builders have done it. I have seen plenty of boats that have sound absorbing material in the engine rooms and mufflers that kill everything except under the hardest acceleration.
    Last edited: Oct 11, 2007
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