Clear Opening?

Discussion in 'Boat Design' started by Niru, Apr 13, 2012.

  1. Niru
    Joined: Jul 2010
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    Location: Philippines

    Niru Mr.

    CLEAR OPENING - Actual dimension that you can pass or see through in a door, hatch, manhole, window, scuttle, or portlight.

    Good day sirs.

    Heres is the prob. i am trying to design an access opening for the engine room, some of the concerns are that the access is weather exposed, small boat around 28 footer - FRP, around 700mm X 550mm-plus/minus is the available space.

    hoping to make it a raised manhole to solve the issue of weather exposure.

    i was looking at ABS rules that will support this issue but still no luck in finding.

    just want to know your experienced opinion/professional opinion on this matter
    i will continue to search for any classification society that supports this issue

    Good to day to all.

    Attached Files:

  2. Petros
    Joined: Oct 2007
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    Petros Senior Member

    Your question is not clear, what exactly is it you want to know? How to make a weather tight "clear opening" for engine in a confined space? need to know the wording of the exact rule that is the problem.
  3. Niru
    Joined: Jul 2010
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    Location: Philippines

    Niru Mr.

    Good day Sir Petros,

    the picture might have confused you... sorry. nevermind the clear opening for the engine
    my concern was

    - is there any rules or requirement for designing a clear opening for the use of engine room access. and for obvious reasons there should be. and what would be its minimum requirement so i can apply it from the space available 700mmX550mm
    (ive seen one in ABS - 600mmX600mm is the minimum but thats for inspection and used for merchant vessels. ill attach the file just in case.)

    Attached Files:

  4. TeddyDiver
    Joined: Dec 2007
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    TeddyDiver Gollywobbler

    It's never big enough so make it to the max size you can. Additional access from the companionway stairs (belts for waterpump and alternator are on that side).
    For weather protection maybe raised deck (bridge deck) or a make the raised manhole with a separate "collar" that fits on top of the opening, upside down inside the opening..
  5. Niru
    Joined: Jul 2010
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    Location: Philippines

    Niru Mr.

    to be honest sir the original "engine compartment access" design was a flush type manhole just like the main-engine access were you can just pull and plug whenever you need to go to the engine room then ofcourse the issue of weather exposure so thats why i have to relocate besides the accommodation door and raised the manhole.

    Thanks for the suggestions sir Ted.

    do appreciated.
  6. The Loftsman
    Joined: Jun 2010
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    The Loftsman The Loftsman

    Raise the opening using an upstand with a water tight hatch on top and be sure to make it big enough to access, failing that have a look at Lloyds rules.

    The Loftsman
    1 person likes this.
  7. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    Wish you guys worked for Catalina. When I want to get a look at something on the engine I put a paddle bit in a drill and drill a hole... Got the idea from the previous owner. Its an '84 so most of the important holes have been bored by now. If you need to actually access the engine or tankage of a production 28'er, step one is to remove a big chunk of deck. I usually use a hatchet to open her up, then dress the edges when I'm ready to redeck it. I can probably do this three times for the price of a hatch. Unless its a govt owned boat and somebody's nephew doesn't want to get his hands dirty doing old boat maintenance. Like Teddy said- its never big enough. Just pull up a sheet and jump down there. How much would it cost to make this process a little easier and lower the pucker factor? Like not mounting the wiring harness to the deck? Or the fire extinguishers or fuel lines?

    Another option is to just go with a little round inspection hatch. When you figure out what you need to do, order the appropriate hatch, download the cutout, and then cut the hole you need. By the time you are done, the hatch has arrived FedEx. Works in the US. I got one in seven hours once. I'd prefer this to having a (cheap plastic) hatch that leaked on the engine and caused the rest of the deck to rot away- which I've seen many times.

    I've had a weird day. Forgive me be for being a bit practical. I don't like adding hatches until there is no other option. I aways want them to be 6" from where the factory put them. Just give me a hull that I can add a hatch or three to without it collapsing.
  8. Stumble
    Joined: Oct 2008
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    Stumble Senior Member

    Find someway of removing the entire covering structure if at all possible. I have spent more days of my life than I care to remember changing out impellers on engines that for some reason the designer figured coul be accessed by reaching over the block through a six inch hole, then down the bulkhead... All blind, all contorted, and on top of a usually hot engine block.

    It pisses me off that a "marine architect" can't remember that engined need to be worked on.
  9. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    This is main reason I dislike small boats. God forbid you have to rebuild engine, I guess that never happens.
  10. Tim B
    Joined: Jan 2003
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    Tim B Senior Member

    You should be able to provide access to the forward part of the engine reasonably easily at this size. You should also be able to fit inspection hatches on each side of the engine, for better access, again, without great difficulty. If you still think you need access (eg. to lift the engine) then you'll have to consider a deck-hatch with coaming. However, that section of deck will no longer be structural, and will require reinforcement.

    Just remember that water likes to run downhill and the deck is at the top, so any deck hatches will require drainage, otherwise you'll end up with a slimy horrible mess (and that's if the hatch doesn't leak).

    Tim B.

  11. Niru
    Joined: Jul 2010
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    Location: Philippines

    Niru Mr.

    thanks for every given opinion...

    regarding the engine side. trying to fit a C7 Caterpillar Engine obvious its inboard for a 28 footer ambulance boat... well thats one part of the story. might be a little big for 28 footer??

    ***proper drainage for deck hatches.
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