Shipping Container Designation 25G1
Decoding the ISO Code 25G1
Every container intended for international transport is marked with a unique code according to ISO 6346 standard. This system ensures standardized identification and handling of millions of containers worldwide. The code 25G1 consists of four characters, each carrying specific information:
Code Structure
| Position in Code | Meaning | Description |
|---|---|---|
| 1st character | Length | 2 = 20 feet (6.058 m) |
| 2nd character | Height | 5 = 9’6″ (2.896 m), High Cube |
| 3rd-4th character | Type and Properties | G1 = General Purpose, passive ventilation |
Detailed Analysis:
- First digit ‘2’: Length of 20 feet, the basic unit of measurement in container transport (TEU – Twenty-foot Equivalent Unit). Enables easy capacity planning in ports, on ships, railways and roads.
- Second digit ‘5’: Height of 9’6″ means this is a High Cube container. This increased height (compared to standard 8’6″) allows for an increase in internal volume of approximately 10–15%.
- ‘G1’: Container type – General Purpose (fully enclosed, protected from weather) + passive ventilation (code ‘1’).
Significance of ISO 6346
ISO 6346 standard is the cornerstone of global logistics. It enables simple and immediate identification of the type, dimensions and properties of containers across all articles of the transport chain.
Technical Specifications of Container 25G1
Table of standardized dimensions and capacities according to ISO 668/ISO 1496-1:
| Parameter | Metric Units | Imperial Units |
|---|---|---|
| External Dimensions | ||
| Length | 6.058 m | 20′ |
| Width | 2.438 m | 8′ |
| Height | 2.896 m | 9’6″ |
| Internal Dimensions | ||
| Length | 5.898 m | 19’4″ |
| Width | 2.352 m | 7’8″ |
| Height | 2.698 m | 8’10” |
| Door Dimensions | ||
| Width | 2.340 m | 7’8″ |
| Height | 2.585 m | 8’5″ |
| Weights and Capacity | ||
| Tare Weight | 2,220–2,300 kg | 4,894–5,070 lbs |
| Max. Payload | 28,180–28,260 kg | 62,130–62,302 lbs |
| Max. Gross Weight | 30,480 kg | 67,200 lbs |
| Internal Volume | approx. 37.4 m³ | 1,320 cu ft |
| Permitted Stacking | up to 216,000 kg | up to 476,200 lbs |
Comparison:
| Type | Volume | Internal Height | Max. Payload |
|---|---|---|---|
| 22G1 (standard 20′) | approx. 33 m³ | 2.393 m | 28,260 kg |
| 25G1 (High Cube 20′) | approx. 37.4 m³ | 2.698 m | 28,180 kg |
Construction and Materials: Anatomy of Durability
Key Structural Elements
- Frame and Walls: High-quality CORTEN steel (weather-resistant steel according to ISO 1161/1496-1). CORTEN creates a protective rust layer that slows corrosion and extends container lifespan up to 25 years.
- Walls: Corrugated steel sheet, which increases rigidity and resistance to deformation.
- Floor: Multi-layer marine plywood (28–30 mm thick) or more modern bamboo plywood (higher ecological value, strength, lower water absorption).
- Doors: Double-leaf, equipped with four locking bars and sealing around the entire perimeter for perfect water and air tightness.
- Corner Castings: Solid steel castings with ISO-compliant holes, designed for crane handling, twist-locks and secure stacking.
G1 Ventilation System
- Passive Ventilation: In the upper part of the side walls are covered ventilation openings (typically 2–4 on each side). They ensure natural air exchange, prevent condensation buildup and reduce the risk of mold or cargo corrosion.
- Advantage: 25G1 container type protects sensitive commodities during long transport in variable climatic conditions. Ventilation is designed so that rainwater cannot penetrate inside.
ISO 6346 Standard: Standardization and Global Compatibility
The ISO 6346 standard defines a complete system for identification and marking of freight containers:
- BIC Owner Code: 3 letters (e.g., MSC, MAE, HZK)
- Equipment Category: Letter U (freight container), J (removable equipment), Z (chassis)
- Serial Number: 6 digits (unique within the owner’s fleet)
- Check Digit: 1 digit calculated by algorithm (verifies correctness)
- Size and Type Code: 4 characters, e.g., 25G1 (see above).
Why is this important?
- Smooth passage through customs systems, automation of records and handling, minimization of errors and risks in transport and storage.
- Enables global transport regardless of carrier, route or continent.
Comparison of Container 25G1 with Other Types
Overview Comparison:
| Code | Length | Height | Type | Ventilation | Internal Volume | Main Use |
|---|---|---|---|---|---|---|
| 22G1 | 20′ | 8’6″ | General Purpose | none | approx. 33 m³ | versatile, dry goods |
| 25G1 | 20′ | 9’6″ | General Purpose | passive | approx. 37.4 m³ | bulky, moisture-sensitive |
| 45G1 | 40′ | 9’6″ | General Purpose | passive | 76.4 m³ | large-volume shipments |
| 22R1 | 20′ | 8’6″ | Reefer (refrigerated) | active | 28.4 m³ | food, pharmaceuticals |
| 22U1 | 20′ | 8’6″ | Open Top | passive | 32.5 m³ | machinery, bulk goods |
| 22P3 | 20′ | 8’6″ | Flat Rack | none | – | oversized, heavy |
When to Choose 25G1?
- If the transported cargo will utilize the increased height (stackable goods, bulky items).
- If it is necessary to protect goods against condensation (e.g., coffee, cocoa, textiles, electronics, paper, wood).
- If you need high flexibility in storage and transport.
Practical Use and Applications of Container 25G1
Overview of Applications
- Transport of Bulky Low-Density Goods: Furniture, plastic products, insulation materials, sports equipment, toys, clothing.
- Moisture-Sensitive Commodities: Green coffee beans, cocoa beans, spices, agricultural products, textiles, paper.
- Storage and Modification: Mobile warehouses, workshops, offices, pop-up shops, construction bases, container architecture (apartments, commercial spaces).
- Transport of Dangerous Goods: According to IMDG, can be used for certain classes of hazardous goods (must be properly marked and secured).
Advantages of High Cube
- Ability to stack pallets to greater height (space utilization).
- Better accessibility when handling tall goods.
- Suitable for modifications (e.g., built-ins, air conditioning, insulation, offices).
Expert Tips and Recommendations
- Loading: Always distribute weight evenly on the floor and observe maximum load according to the technical sheet. When stacking multiple layers of pallets, it is necessary to verify load capacity and stability.
- Storage: Place the container on a reinforced, level surface (ideally concrete pads or railway sleepers). Ensure free access to the doors.
- Maintenance: Check the condition of door seals, ventilation, floor, and any signs of corrosion. Regular maintenance extends container lifespan.
- Modifications: When making structural changes (windows, doors, electrical installation), comply with applicable building and fire safety standards.
Frequently Asked Questions (FAQ)
1. What is the main difference between 25G1 and 22G1?
25G1 container type is High Cube (height 9’6″), 22G1 container type is standard (8’6″). Other dimensions are identical, the difference is in volume and usable height.
2. How many euro pallets fit in a 25G1 container?
In one layer 11 euro pallets (1200×800 mm). Thanks to the greater height, pallets can be stacked better.
3. What is the ventilation for type G1 used for?
Passive ventilation prevents condensation and mold formation. It is important for transport of agricultural and textile commodities.
4. Is the 25G1 container watertight?
Yes, despite the ventilation openings, the container is fully watertight thanks to special covers.
5. What does maximum gross weight mean?
It is the sum of the container’s own weight and the maximum permitted cargo. Exceeding it is illegal and dangerous.
Tips for Purchase and Use
- Selection: Consider the nature of the cargo, height requirements, type of goods and frequency of use.
- New vs. Used: New containers have guaranteed tightness and lifespan, used ones can be cost-effective for storage.
- Certification: For international transport, the container must have a valid CSC plate (Container Safety Convention).
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