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Topic: Question For The Ship Experts...
Username: Darksnowynight
Posted 2012-12-27 04:53:34 and read 2714 times.

So I'm driving home from work this morning, and because of an errand, my route takes me an exit or two further down the 110, into San Pedro. As those of us in the area know, this gives one a pretty neat overview of the western end of the Port of Los Angeles' Long Beach facility (It's really quite a sight if you all ever get the chance). And I noticed something odd.

A container ship being loaded (pretty sure their loading, and not unloading in the early morning hours, though it's possible I have that backward) at one of the closer piers. The Load didn't look terribly asymmetrical, but this ship had an unmistakable list (to starboard). Prominent enough that myself and the lady in the car with me could easily see this from the freeway. If I had to guess, I would say that it was at 1.5 to 1.75 degrees.

My question to the Ship Experts here is this. Is this normal? The load did look slightly unbalanced, but the thing is that the on deck load was stacked higher on the port side, so if anything, I'm guessing it should have been listing the other way. Obviously other forces are at work there. I'm wondering if there is a convention to the way these cargoes are off-loaded. It does look as though there are enough cranes to load the cargo evenly, but perhaps this is not possible for belowdecks loads?

Anyway, I'll be back out on the road in a few hours. If this ship is still there, and still doing this, I'll try to snag a shot or two. Thanks in advance guys!

Topic: RE: Question For The Ship Experts...
Username: petertenthije
Posted 2012-12-27 05:40:39 and read 2686 times.

Can happen. Remember that not all containers are the same weight. It's very possible that on the port side there were only light containers whereas on the starboard side there were only some heavy containers or bulk goods. During loading and unloading a specific unloading pattern is made. This is done for balance purposes, but also for logistical purposes because you want to make sure the right truck/train/shuttle is available for the right container.

Loading a ship is not just a matter of simply stacking boxes till you run out of space. Each container is given an assigned position, same as with designated seating on an airliner. This is done for a variety of reasons:

  • Weight and balance. The ship has to be balanced both longitudally and horizontally. For better stability the heavier containers have to be stowed as low as possible.
  • Loading and unloading. A container that is unloaded at the next port is ideally placed on top. A container that is unloaded at the last port of call is ideally placed at the bottom.
  • Regulatory requirements. Some containers contain cargo that has to be stored below decks (e.g. medicines, hazardous material that reacts to water). Other containers have to be stored above deck (e.g. fire hazard cargo, explosive cargo).
  • Special requirements. For instance refrigerated containers (reefers) or open top containers. Reefers are plugged into the ship's electricity grid. Not every container position has a power outlet, so that limits the options to load reefers. Open top containers are, of course, open so you can not put other containers on top of them.
  • Customer requirements. Some customers may require that their container be placed below deck. Or that it is inspected at a given interval while en-route.

  • [Edited 2012-12-27 05:44:18]

    Topic: RE: Question For The Ship Experts...
    Username: zanl188
    Posted 2012-12-27 10:32:48 and read 2605 times.

    Container ships will also fill and/or empty ballast tanks to balance the load.

    Where the containers are concerned it's a compromise between ship balance & ease of on/offloading. Ballast tanks make up any difference to provide adequate stability.

    Topic: RE: Question For The Ship Experts...
    Username: jet-lagged
    Posted 2012-12-30 15:56:51 and read 2448 times.

    Shipping companies uses specific application software to help them place containers.

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