Anatomy of a Shipping Container
Welcome to the most comprehensive dictionary page that reveals every detail of shipping container anatomy. This page is intended not only for logistics specialists, manufacturers and sellers, but also for anyone planning to buy a shipping container, modify it, or is interested in the technical aspects of global transport. In each section you will find expanded, practical and technical information based on the latest world and Czech sources, including specific standards and material specifications.
Basic Frame Structure – Container Skeleton
The frame forms the backbone of the container and ensures its load-bearing capacity even at maximum load. It is a highly precise steel structure whose individual elements are designed and manufactured according to strict international standards (in particular ISO).
Corner Castings
| Parameter | Value/Description |
|---|---|
| Standard | ISO 1161 |
| Material | Cast steel, e.g. ASTM A27 Grade 70-36 |
| Dimensions | 178 mm × 162 mm × 118 mm |
| Number per container | 8 |
| Openings | 3 on each corner casting |
| Fastening | Welding |
| Quality control | ISO 1161 certification, strength tests |
Main roles:

- Lifting and handling: Openings are precisely calibrated for spreaders, cranes and clamping mechanisms.
- Stacking: All weight of stacked containers is transferred through corner castings and posts – the roof is NOT load-bearing.
- Fastening: Twist locks secure safe connection between containers and with transport vehicles.
Technical highlights:
- Corner castings are milled with millimeter precision, which is essential for global compatibility.
- Cast steel is preferred due to extreme strength, weldability and resistance to long-term stress.
- Welding is the only recommended fastening method – only this guarantees connection integrity.
Corner Posts
- Material: High-strength steel, thickness up to 10 mm
- Function: Transfer vertical forces; their strength is essential for stacking safety
- Control: Repairs and replacements always according to IICL standard to ensure structural safety
Top and Bottom Rails and Cross Members
| Element | Material | Function |
|---|---|---|
| Top rail | Steel (e.g. Corten) | Ensures longitudinal rigidity, load-bearing capacity and connection of corner posts |
| Bottom rail | Steel | Weight transfer to cross members, floor support |
| Cross members | Steel beams | Even weight distribution of cargo, increased floor clearance |
- Cross member spacing: Usually 305 mm (12 inches) for maximum floor support
- Advantage: Due to robust construction, there is no need to build solid foundations for container buildings
Cladding and Floor – Protective Shield
Wall and Roof Panels – Corten Steel
| Property | Value/Description |
|---|---|
| Material | Corten steel (COR-TEN, weathering steel) |
| Thickness | 1.6–2.0 mm |
| Surface finish | None required; a self-healing layer forms on the surface |
| Service life | 20+ years in aggressive outdoor environment |
| Function of corrugated sheets | Increases rigidity and resistance to deflection and impact |
| Additional info | Also used on bridges and sculptures (e.g. Angel of the North) |
Why Corten Steel?
- Creates a stable rust layer on the surface that acts as a protective shield – the so-called “self-healing mechanism”.
- Resists sea salt, rain and wind without need for coatings.
- Allows long service life even under extreme stress.
Front End Wall
- Construction: Profiled Corten sheet, firmly welded to front corner posts
- Function: Solid barrier that prevents deformation and protects cargo during transport
Floor
| Material | Description |
|---|---|
| Marine-grade plywood | 28 mm thick, laminated, impregnated against pests |
| Alternative | Bamboo flooring – more ecological, durable |
| Installation | Bolted to cross members |
| Load capacity | 2,000–3,000 kg/m² (depending on container type) |
| Treatment | Insecticides according to international shipping regulations |
- Advantage: The floor is designed to withstand repeated movement of forklifts and point loads when handling heavy goods.
Door Assembly and Identification
Cargo Doors
| Element | Description |
|---|---|
| Material | Steel, often Corten steel |
| Opening | Up to 270° for maximum access |
| Reinforcement | Horizontal and vertical for increased strength |
| Sealing | Rubber around entire perimeter |
| Locking | 2× (for 20′, 40′ – 4×) locking bars |
Locking Bars and Cams
- Material: Steel
- Function: Lock doors along entire height, ends (cams) fit into holders in the frame
- Safety: Handles are equipped with padlock capability, often in protective box against cutting
Door Gaskets
- Material: Rubber (EPDM, NBR)
- Function: Ensures water-tightness, air-tightness and protection against dust and pests
- Tightness test: Light test – no light should penetrate inside after closing
CSC Plate
| Name | Description |
|---|---|
| Standard | International Convention for Safe Containers (CSC), 1972 |
| Location | Left door leaf |
| Data | Manufacturer, year of manufacture, maximum gross weight, stacking weight, date of next inspection or ACEP program |
- Without a valid CSC plate, the container is not suitable for international transport.
- ACEP: Continuous inspection and maintenance program that allows operation without the need for regular periodic inspections.
Special and Supplementary Elements

Forklift Pockets
- Use: Allow handling of empty container with forklift
- Standard: Common for 20′ containers, less frequent for 40′ due to safety and weight
- Dimensions: Standard 362 mm (width) × 115 mm (height), spacing 2,050 mm
Twist Locks
- Function: Mechanical connection of containers to each other and to chassis/wagon/ship
- Use: 90° rotation secures locking in corner casting

Gooseneck Tunnel
- Location: In the middle of the floor at the front end of 40′ containers
- Function: Allows seating on special “gooseneck” chassis and reduces overall height of the unit
Ventilators
- Number: 2–4 per container
- Function: Passive ventilation, reduces risk of condensation and mold formation
Materials and International Standards
Most Common Materials
| Element | Material |
|---|---|
| Frame, walls, roof | Corten steel (COR-TEN) |
| Corner castings | Cast steel (ASTM A27 etc.) |
| Floor | Water-resistant plywood, bamboo |
| Sealing | Rubber (EPDM, NBR) |
Main International Standards
| Standard | Description |
|---|---|
| ISO 1161 | Corner castings – dimensions, strength, quality control |
| ISO 668 | Basic dimensions and container classification |
| ISO 1496 | Technical requirements for construction and testing |
| CSC (1972) | Safety standards for construction and maintenance |
| Customs Convention (1972) | Simplification of customs procedures for containers |
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A 40ft open side container is a specialized ISO shipping container in which one full 40-foot long wall is replaced with bi-fold or multi-panel doors that swing open to provide unobstructed access along the entire side of the unit. Unlike a standard shipping container — where the only way in is through the 7-foot-8-inch-wide double doors at one end — an open side container lets you reach every pallet, every piece of equipment, and every inch of stored cargo from the side, without ever having to dig through layers of inventory. The standard end doors remain intact, giving you two fundamentally different access modes in a single unit.
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