Insulated Fish Hold with Concrete floor above steel deck

Discussion in 'Boat Design' started by Maritimer, Jan 27, 2014.

  1. Maritimer
    Joined: Jul 2007
    Posts: 29
    Likes: 2, Points: 3, Legacy Rep: 58
    Location: Canada

    Maritimer Junior Member

    I am working on the design of a large steel fishing vessel with an insulated fish hold. The fish hold will have a small forklift used to stack pallets of frozen boxed fish product. The bottom of the hold will consist of a steel deck, then 200 to 300 mm of insulation then a concrete floor something like 150 mm thick with re-bar.

    I was wondering,
    1) How does Class deal with the structure? I am guessing you do not have to calculate wheel loads from the forklift as the forklift will operate on the concrete slab. Just a worst case pressure load for the steel deck? Does Class care about the construction of the concrete slab?

    2) How do you design the concrete slab for the flexing of the vessel and applied loads. What is typically done?

    Any advice is appreciated.
  2. NavalSArtichoke
    Joined: Oct 2013
    Posts: 431
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    Location: GulfCoast

    NavalSArtichoke Senior Member

    What's the purpose of the concrete floor? Besides making life more difficult. Steel decks capable of supporting wheeled vehicles have been designed (see RO/RO vessels, car carriers, etc.)
  3. Maritimer
    Joined: Jul 2007
    Posts: 29
    Likes: 2, Points: 3, Legacy Rep: 58
    Location: Canada

    Maritimer Junior Member

    The concrete floor is used for several reasons.

    1) The fish hold is kept at -30 degrees C so it needs to be well insulated. A continuous steel deck connected to ship structure and un-insulated at any point takes the cold into other areas of the vessel such as ballast tanks which is not good. The concrete is isolated on top and sides by insulation and has good rigidity.
    2) The fish hold is a hard environment to keep paint on a deck and you do not want rust in the product.
    3) Concrete helps for solid ballast low in the vessel.

    I have talked with a civil engineer on concrete slabs and they don't see it being a big deal likely a 150-200 mm thick concrete slab with lots of rebar and the correct insulation to take the compressive loads.
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