How Shipping Containers are Stacked on Cargo Ships

How Do So Many Shipping Containers Stay Secured On Cargo Ships

There is a method to the shipping container madness. The bottom shipping containers or “first tier” are secured with twist-locks, locking them down to the deck of the ship. Lashing rods and turnbuckles are used as additional strength to help secure and hold the containers in place. The bottom containers support the weight of all the additional containers that will be stacked on top of it. The middle or “higher tier” containers are locked in with an automatic twist-lock. These mechanisms are attached when the unit is being raised from the pier onto the cargo ship. When the shipping container is positioned on top of another container the auto twist-lock pops into the lock position, locking them together. When a shipping container is unloaded there is a special rod that is used to unlock the twist-locks. Most cargo ships have cells (vertical slots made by long metal rails) in the cargo holds that hold units in place to prevent them from moving or sliding.

How High Can Shipping Containers Be Stacked

Back in the early days of shipping, before the sophistication of twist-locks and cells came about, cargo carriers were only allowed to stack boxes 5 or 6 high. These days, you can see them in stacks of 10-12 high. Now that’s a lot of containers!

shipping container ship on the water with tons of containers loaded on it

Shipping Containers Lost At Sea

It is estimated that hundreds or even thousands of shipping containers are lost at sea each year. Most often, a shipping container going overboard is due to harsh weather encountered at sea, such as hurricanes. Containers do not simply fall off ships. While most losses are due to weather, there are instances where it was negligence, the container weight was inaccurate, or improper stowage planning.

How Do I Ship My Own Container?

If you need a shipping container, ATR can help! We sell and rent new or used shipping containers and can deliver them throughout the USA for you. If you need your container shipped overseas, a cargo ship will be needed. We can point you in the right direction to help you get that set up with the appropriate company.