Shipping container interlocks or stackers are used to fix and lock containers together in a stack and stop them falling off the container vessels when they are at sea. These heavy duty interlocks are the same type used at many ports and on container boats around the world.
For domestic use, if you want to stack a container and ensure it can’t get blown or pushed off its supporting unit then these work extremely well. Much like the shipping containers themselves these interlocks are probably over-engineered for domestic storage use, but they are manufactured on such a scale and are so fantastically strong that they offer a very cost effective option. They are the best quality locking mechanism we know of.
These interlocks are designed for use with any ISO standard width shipping container. You may also want to check the containers that you are stacking have 4 sets of corner castings. Our refurbished range of shipping containers, for example, commonly won’t come out with 4 sets of corner castings.
Do I need a set of shipping container interlocks when stacking containers?
This is a very subjective question. We do know that empty or near empty containers can, and do, very occasionally blow off the top of container stacks.
Their capacity to blow off will be down to how much weight is in each shipping container, how exposed these containers are to prevailing winds, how strong the wind is, how the containers are orientated in relation to the wind direction, and how high they are stacked.
In all honesty if your top container is loaded with very heavy weights, and if your only stacking 2 high you can probably get away without these interlocks.
However for a set of 4 interlocks these are an awful lot cheaper than the shipping containers, which in turn are generally worth a considerable amount less than anything your going to be putting inside these units. We recommend these as a matter of course for any empty stacked containers or any containerised units that will have people working inside.
Things to check before ordering
- Interlocks will come in a set of 4, you need to check both containers (the one you have on the bottom now and the one you want to stack on top) both have 4 corner castings for these to lock into. Commonly a container made from cutting up a larger shipping container may not have all 4 corner castings (in our case our refurbished container range is often made from cutting down larger containers)
- These interlocks are only designed to work with standard 8ft wide containers. Pallet-wide containers (circa 8ft 2′ wide) require different interlocks.
- If in doubt – just make sure you buy all your shipping containers from us – and we’ll do all the checking for you! (or just ask us / send in some photos perhaps if you want us to look at a container you already have. )
How to Install:
- Place the interlock into the top corner castings on your bottom container
- Always position ‘pointy end up’ – This pointy end can help guide in the top container when positioning it.
- Check the locking action: When you lock the interlocks you want to ensure the locking bar doesn’t stick out from the containers. If it does you can turn the interlock around through 180 degrees so this doesn’t happen (this isn’t;’ essential but it might look better like this)
- Lift your container onto the top of the 4 interlocks when you have checked the above points carefully beforehand – there may not be any going back.
- Push the locking bar on each interlock to lock the top container in place
- That’s all!
These are not designed for:
- Hanging a container on the front of another stacked container for any form of overhanging unit
- Hanging a container down from the underside of a top container, gantry or other item at height
- Pulling, pushing or otherwise being used to move a shipping container
These are solely designed to stack one container on top of another container and to be locked into place so both are safe and secure. We imagine, care of their strength, they would work in a number of other applications but these interlocks are not designed or tested for other uses and we cannot guarantee their safety for use outside their designed purpose. If moving a pair of stacked and locked together containers, the locks should be undone and the containers moved individually.