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Marines assigned to the 24th Marine Expeditionary Unit (24th MEU) prepare to launch amphibious assault vehicles from the welldeck of the amphibious transport dock ship USS New York (LPD 21). New York and the embarked 24th MEU are part of the Iwo Jima Amphibious Ready Group deployed in support of maritime security operations and theater security cooperation efforts in the U.S. 5th Fleet area of responsibility. (U.S. Navy photo by Mass Communication Specialist 2nd Class Zane Ecklund/Released)

Marines assigned to the 24th Marine Expeditionary Unit (24th MEU) prepare to launch amphibious assault vehicles from the welldeck of the amphibious transport dock ship USS New York (LPD 21). New York and the embarked 24th MEU are part of the Iwo Jima Amphibious Ready Group deployed in support of maritime security operations and theater security cooperation efforts in the U.S. 5th Fleet area of responsibility. (U.S. Navy photo by Mass Communication Specialist 2nd Class Zane Ecklund/Released)

Comments

  1. I am not an engineer so I don’t understand all the forces of load and such. But I am always amazed at how strong the decks of these ships are to support the enormous weight of their cargo. You can’t even put a water bed in some homes for fear of the floor bowing. But they have a dozen AAV, around 30 tons each, arranged on that well deck. Same thing with aircraft carriers supporting all those planes, or container ships filled to the gills with containers. It is amazing. I wonder if they ever get to the point where they even have to consider how much of a load they are placing on those decks.

  2. Um, the designers sorta know the loads they’ll be facing and then add a hefty amount of margin for growth. It’s part of the reason why the beasties take several years to build (CV/LPD/LHA/HD).

  3. Weight on water isn’t a problem as long as the ship’s mass displaces more water mass than it.

    Ships floating in water are basically weightless. That takes stress off the structure of the ship.

    Ever see a container ship with loaded conex piled 10 high above the gunwales?

    1. Ever see a container ship with loaded conex piled 10 high above the gunwales?
      Reply

      Like this.

      As I said I am not an engineer so I don’t know how much stress is taken off the ship’s structure in water. I would still think those decks have got to be extremely strong to hold planes, tanks, containers, etc. It is mind boggling how much weight we are talking about.

      1. If the stress is taken down straight to the hull plating (i.e. in direct contact with water), the force pushing down and the buoyancy force are equal. In a Gator, with large-span open decks, the overall weight is taken through the outer frame to the hull and water. Each deck only needs to bear the span weight. Since modern US naval construction has transverse (side-to-side) frames (big beefy under-deck girders) every 2 feet or so, there’s plenty of load-carrying structure to bring that weight into the frame and into the water.

        Besides, the weight of the cargo is nothing compared to the hull stresses that the decks are designed to bear. A Gator in heavy seas places far more strain on its decks through the twisting of the hull in those seas than a platoon of AAVs ever will.

  4. Thanks for the replies. In my search for some photos of big honking ships, I cam across this. That is one big load. It is the same ship that carried the USS Cole home after it got hit in 2000.

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