Question about stacking containers on container ships

Despite having started a uniform size--8x8x20, shipping containers are no longer very uniform.

To better address "inter-modal" (train-truck-ship) the 8x10x40 container started being used.

Cargos of light things would fill those up before getting to max weight, so the "jumbo" 8x10x48 was introduced.

Which was good, except, for forklift loading, a 13' "hi-cube" worked even better.

For even more 'jumbo" there are the 53' model containers (and some 56' ones, too).

In that view above you can see the 10 & 13 tall stacks.

The loading on the ship will be heaviest lowest and closer to midline.  The rhyme & reason of it is in the can, not its shape, size, or vendor color.  A given can might be as full of plush toys as diesel engines--the latter are just more likely in a stack near the midline.

As to modeling that-that, I have fewer answers for.

Sometimes there are gaps in the stack load which cant be helped ...

Like the M/V Hanjin Pennsylvania

One dead, 19 injured,  ship survived.   Investigation showed that some containers containing fireworks were "mis-identified" on the manifest.

Dave,

I think the narrow gap you circled in that pic of Bremen Express Is due to a gap between hatch covers at the bottom of the stack.  i'd have to look at my model of the Colombo Express to confirm.  The containers are stacked on top of the hatch covers, which are in sections over the below deck hatches.  There are usually three covers on a hatch, which would normally leave two narrow gaps as seen from above or the ends.  

Fred

My daughter is a naval architect who worked for a time for a company who designed container ships and the computer programs for loading them. There is another factor besides the size and weight of the containers. If the ship makes multiple stops to load or off load, as some do, you need to consider the placement of the containers so you have ability to load or offload containers without off loading the entire ship.

I think that might be it.  I looked at a photo of Chicago Express.  Hapag-Lloyd has a photo that shows a consistent split front to back.  Six stacks on port and starboard and five down the center.  There are some rows that don't have splits.  In any event I saved that image for reference.

Thanks!

Dave

I read a neat book about container ships recently. It said some containers  had refrigeration equipment, most do not.  The refrigerated containers were stacked in only certain locations, and that affected how the whole load was stacked.

Reefer containers are only put close to the outlets for plugging them in, naturally.  By the way, on the Alaska run we also carried reefers that were set to 45 degrees, which kept cargo like flowers or lettuce from freezing.  The reefer boxes also have a heating element.

In the case of cargo from or for multiple ports, because the stacks are aligned with the hatch covers, you can offload that hatch cover, say in the center part of the hold, take the cover off and work below decks in that section without disturbing the cargo on either side.  Ideally, to save crane moves, you want to load a box, then pick another in an adjacent row to discharge without moving the crane spreader off the ship.  Planning is a complex operation with a whole lot of factors involved.  There is still a lot of muscle work involved too.

Edit:  For a good history of the container industry, try 'Box Boats'.

Great thread,I'm learning lots here

I was told once that at the terminal before loading that the destination papers are logged in and the containers are measured and weighed (double check and don't just trust the papers). It all goes into the computer and the software decides which containers are loaded and in what order and where. Even a small error can cause problems.

onyxman

Reefer containers are only put close to the outlets for plugging them in, naturally.  By the way, on the Alaska run we also carried reefers that were set to 45 degrees, which kept cargo like flowers or lettuce from freezing.  The reefer boxes also have a heating element.

Great stuff guys.  I looked at some of the marketing photos from Hapag-Lloyd and you could clearly see the gaps right along the hatches.  I saw one example where they had the center section open and were removing containers from below decks.  

Thank you!

Dave

There's a TV series called Mighty Ships that originally was on Discovery and is currently running on the Smithsonian Channel that includes a feature on the Emma Maersk, one of the largest container ships in the world. It doesn't answer the question first asked here but it sure is interesting. Episodes are available on line. There's one on the navy ship New York which ran just as I finished my model of the ship. Great stuff - look for it.

I did a google search for container logos when I was making my Colombo Express.  Found a neat site that had dozens of container logos.  Used them to make inkjet decals of other container shippers so load would not be all HL.

Load planning is all done with a computer program that considers destination, weight, hazardous content?, etc.  This all reflects stability and also stress on the hull.  It's real complex.  For instance, you can't have flammable cargo near a powered reefer.  One time in Tacoma a crane operator lifted a container from a ship that came from China and he noticed that it seemed to be way lighter than the manifested 20 tons, so it got flagged and Homeland Security found it was full of immigrants. Still alive, luckily for them. There is also a lot of radioactivity detection going on, and big X-ray machines check boxes at random.  Those crane operators make big bucks, but it is a highly skilled job.  This is obvious when you watch them trying to train a new guy.  Hilarious!

This is in Anchorage, taken from the bridge window.

Not sure, but the spaces may be for walkways to access containers. Going off the Mighty Ships series, crew members have to be able to get to containers for fires or in case a "reefer" container needs attention. It's just a guess though.

Everything is pointing to the containers being loaded in groupings over the lower deck hatches.  As mentioned above you can remove the containers on the top deck in one section to get to the containers in the lower deck section without disturbing the ones around them.  

There are access areas front and back of the containers where they are secured and braced.  

If you go to YouTube and search container ship loading you can find some excellent video of containers being loaded and unloaded.  Pretty interesting to watch!

Dave