Complete Guide to Shipping Container Classification: Types, Materials, and Sizes

Shipping containers are the "standardized units" of global trade, and their classification directly impacts logistics efficiency and costs. This guide systematically explains container categories from types, materials, and sizes, with practical recommendations to help businesses optimize cargo transportation.

1. Classification by Purpose and Structure

1. Standard Containers (GP/HQ/DC)

   • GP (General Purpose): Dry containers for general cargo. Common sizes: 20GP (28 cubic meters), 40GP (58 cubic meters).
   • HQ/HC (High Cube): Taller (1 foot higher than GP, ~30 cm), ideal for lightweight goods. 40HQ holds ~76 cubic meters.
   • DC (Dry Container): Synonymous with GP, emphasizing dry cargo compatibility.

2. Specialized Containers

   • Open-Top (OT): Removable canvas roof for oversized items like machinery or steel.
   • Flat Rack (FR): No roof or walls, designed for heavy machinery, pipes, or vehicles.
   • Reefer (RF): Refrigerated units for perishables (food, medicine), usually white to reflect heat.
   • Tank (TK): Liquid-tight containers for chemicals, oils, or beverages.
   • Garment (DH): Built-in hanging rods for wrinkle-free clothing transport.
   • Ventilated (VC): Airflow-enabled for agricultural products like fruits and vegetables.

2. Classification by Material

1. Steel Containers: Durable and cost-effective but heavy and prone to rust. Lifespan: ~12 years.
2. Aluminum Containers: Lightweight (20%-25% lighter than steel), corrosion-resistant, ideal for sea freight. Lifespan: ~15 years.
3. FRP (Fiberglass) Containers: Superior insulation and anti-corrosion, used for sensitive electronics.
4. Stainless Steel Containers: Highest durability, maintenance-free, common in tank containers.

3. Classification by Size

1. Standard Sizes

   • 20ft (20GP): External dimensions ~6.06m×2.44m×2.59m, max load ~21 tons.
   • 40ft (40GP/HQ): 40HQ offers ~76 cubic meters, ideal for low-density cargo.
   • 45ft (45HQ): ~86 cubic meters, suited for bulk lightweight goods but lower weight capacity.

2. Non-Standard Sizes: Includes 10ft mini-containers or custom 30ft units for niche needs.

4. How to Choose the Right Container?

1. Cargo Type: Heavy goods → standard containers; lightweight/bulky items → high cube; liquids → tank; perishables → reefer.
2. Cost Efficiency: High cubes maximize space without significant cost increases.
3. Loading Requirements: Oversized cargo may require open-top or flat rack containers with crane access.