How to Stack Shipping Containers Safely: AU Guide 2026

Shipping containers can be thought of as giant, hollow Lego bricks.

They’re able to be stacked, which maximises capacity and space utilisation on container ships. But on dry land this stackability also means you can create structures of different shapes and sizes: dense storage, multi-level tiny homes, remote worker accommodation and more.

Stacking containers is not a matter of simply placing one container on top of another. The strength, structural integrity and safety of the stack is key.

In this guide we’ll explain safe shipping container stacking methods, essential equipment, and the rules and regulations you need to know in Australia.

Understand the basics of container stacking

To stack shipping containers safely, you first need to understand the basics of how this stacking works.

Stackable sizes

While shipping containers are available in a range of different lengths, the standard sizes are 20ft and 40ft. You can only safely stack the same size containers – i.e. you can’t stack two 20ft containers on top of one 40ft container.

Connection points

Shipping containers are connected by corner castings – metal blocks with holes in them that can be found at each of the eight corners of the container. They’re used for stacking, joining and lifting containers.

Connectors

Shipping containers are connected using stacking pins or twist locks. Ultra-secure twist locks are almost always used. Stacking pins are only used for temporary stacks, as they don’t secure the container, just guide it into place.

Essential equipment for safe stacking

What equipment do you need to safely stack shipping containers? Basics include:

• A crane/lifting device: The crane must be capable of comfortably handling the weight of the container. A heavy duty forklift may be able to handle small containers.
• Twist locks/stacking cones: Use twist locks to secure containers in place, stacking cones for temporary stacks.
• Inspection tools: Use load cells to check weight, spirit levels to check containers are sitting square, and safety chains to secure temporary stacks created with stacking cones.
• PPE: Protect yourself with a hard hat, gloves, high-vis clothing and steel capped shoes.

A 10-step guide to stacking containers safely

1. Place the first container on a level, structurally sound base (concrete, gravel, compacted soil).
2. Plan your stack. Aim to put the heaviest containers at the bottom, lightest at the top.
3. Inspect each container for any structural damage or weaknesses.
4. Use a crane/lifting device and qualified operator to lift and align the containers.
5. Lower slowly, ensuring the top container nestles onto all four twist locks.
6. Engage the twist locks to secure the containers together.
7. Perform a visual check after placing each container.
8. Repeat until you complete the stack.
9. Consider adding bracing if the stack is secured with stacking cones, or in a windy location.
10. Re-inspect the stack regularly, especially after strong winds or impacts.

Legal and safety regulations in Australia

There are two relevant standards that apply to stacking shipping containers in Australia:

• AS3711.10:2000: Freight Containers, Handling and Securing, Section 8: Stacking on Ground.
• AS/NZS 1170.2:2021: Structural Design Actions, Part 2: Wind Actions.

Key considerations as part of these standards include:

• Groups of stacked containers should be ‘boundary stacked’ – smaller stacks on the outside, taller stacks on the inside.
• Long-term stacks must be secured using rated twist locks.
• It is recommended that all stacks undergo a risk assessment from a structural engineer.
• Stacked containers should be placed parallel to prevailing winds.
• In areas of high wind, early warning devices like wind anemometers are recommended.

How high can you safely stack shipping containers?

While there are no hard and fast rules on maximum height, standalone container stacks on dry land generally top out at three containers (two in windy areas). On modern container ships, stacks can reach 20 containers in height in the middle of the ship.

Safety: the foundation of your container stack

The ability to stack and connect shipping containers opens up the opportunity to create endless structures, from storage to workplaces to multi-level homes.

But these projects are only possible if the stack is structurally sound. You need a solid foundation, a level base, correct alignment, proper securing, and compliance with rules and regulations.

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