We Cut a Shipping Container in Half - Modifying A Sea Can To Go Underground! | The Container Guy
In this video, we will be cutting a shipping container in half, lengthwise! Many people have cut sea containers in half either to turn a 40-foot into two 20’s or a 20-foot into two 10’s. But for this customer, they needed the container to be smaller in width so it would fit down a mine shaft.
In order to fulfill their request, we needed to engineer a unique footer, header and posts so the container can be split apart but not lose any of its integrity.
Watch this video as we cut a sea can in two, weld on vertical posts, headers, and footers and bolt them back together!
We will also be installing customized steel shelving and a workbench in this container using our strut mount brackets and strut channels.
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Cutting a 20-Foot Shipping Container in Half for Underground Mining Use
In this walkthrough, Channing McCorriston, The Container Guy, demonstrates how a 20-foot shipping container can be cut in half, reinforced, and reassembled underground for use in a mining environment.
The customer required the container to be split into two manageable sections that could fit down a mine shaft and then be securely reconnected below ground. The result is a structurally sound, modular underground workspace built with safety and alignment precision in mind.
Selecting the Right Container
Precision started with container selection.
The team chose units that matched their engineered model, specifically looking for 60 mm square tubing at the back top. Containers with taller e-channel sides were avoided due to dimensional incompatibility.
Matching the correct structural profiles ensured the modification would align properly during reassembly.
Reinforcing and Preparing the Structure
Before cutting, corner castings and vertical posts were tack welded and tested using magnetic particle inspection to confirm weld integrity.
Twenty-foot floor channels were welded with alignment dowels built in. These dowels are critical. When the two halves are rejoined underground, the dowels automatically align the floor system without requiring manual adjustment in tight conditions.
This dramatically improves safety and ease of assembly.
Cutting the Container in Half
The container was cut directly down the center.
A wood skill saw was used to cut the plywood floor, while a metal cutting skill saw handled the steel cross members, roof panels, and side walls. Temporary roof supports maintained structural stability during the process.
Structural channels were routed so members could sit flush over the wood floor. Countersunk screws created a smooth finish and eliminated tripping hazards.
Structural Kit and Bridge Fittings
Once separated, vertical posts and headers were installed and welded into place.
Bolt-on bridge fittings were added to clamp the two halves together during reassembly. These fittings use dual-threaded bolts that pull the containers tightly together. While they allow minor movement, the floor dowels prevent twisting or misalignment.
Temporary transport posts were installed to maintain rigidity during lifting and handling. These posts were removed once the container was assembled underground.
Man Door and Interior Buildout
To prevent damage during hoisting, the man door frame was installed underground rather than at the surface.
A dual swinger man door was fitted into a precisely sized rough opening. The interior was then lined with a modular strut system, allowing the installation of shelving, workbenches, and hose reel racks.
Shelving was constructed from galvanized steel and rated at 300 pounds per bracket, supporting up to 900 pounds per shelving section. Wood shelving was avoided to reduce fire hazards underground.
Electrical and Power Integration
The container was wired with 240 volt power for lighting and workbench use.
A junction box with bus bars links both halves electrically, allowing unified lighting and power management once assembled underground. Heavy conduit protects wiring and ensures durability in the mining environment.
The modular strut system makes future adjustments or additions straightforward.
Ventilation and Condensation Control
Underground environments experience temperature swings that can cause condensation.
To manage airflow and reduce moisture buildup, Big Air 45 vents were installed. Proper ventilation helps maintain a safer and more stable working environment.
Final Thoughts
By combining precision cutting, reinforced structural kits, alignment dowels, and modular interior systems, this project transforms a standard 20-foot container into a safe and functional underground workspace.
The design balances strength, usability, and adaptability, offering a practical solution for mining operations that require modular infrastructure below ground.
As demand grows in the mining sector, this approach demonstrates how container modification can meet highly specialized industrial needs with engineered precision.