Open-Top / Hard-Top / Flat-Rack Containers: Special Container Solutions for Over-Height and Over-Weight Cargo

When cargo exceeds the internal dimensions or weight limits of standard dry containers, specialized containers are required. Open-top, hard-top, and flat-rack containers are the three most commonly used solutions for out-of-gauge cargo.

I. Core Parameter Comparison of the Three Container Types

II. Open-Top Container

Applicable Scenarios

Open-top containers have a waterproof tarpaulin cover and allow cargo to be loaded from above. Suitable for cargo that is over-height but does not exceed the container frame height.

Suitable Cargo Types:

• Cargo exceeding the standard container door height (>2,280mm) but not exceeding 2.3m
• Equipment that needs to be lifted in from above
• Large glass sheets and stone slabs
• Long steel pipes and timber (may protrude beyond the container, subject to out-of-gauge handling)

Usage Method

Open-Top Container Loading Procedure:
1. Open the tarpaulin roof → Remove bows → Open the top
2. Crane lifts cargo into the container from above
3. Cargo in position → Secure/lash
4. Install bows → Cover with tarpaulin → Secure tarpaulin with lashings

Open-Top Container Costs

III. Hard-Top Container

Applicable Scenarios

Hard-top containers are similar to open-top containers, but the roof is a removable steel structure rather than tarpaulin. Suitable for scenarios where the cargo needs load-bearing capacity above it.

Core Differences from Open-Top Containers:

Suitable Cargo:

• Over-height cargo requiring rigid overhead protection
• Return shipping scenarios where empty containers need to be stacked
• Over-height machinery and equipment

IV. Flat-Rack Container

Applicable Scenarios

Flat-rack containers have no side walls or roof – only a floor and end walls – allowing loading from any direction. Suitable for over-weight, over-sized, and irregularly shaped cargo.

Suitable Cargo Types:

Flat-Rack Usage Key Points

Flat-Rack Lashing Ring Layout

20ft Flat-Rack Lashing Ring Layout (floor top view):
┌──────────────────────────────────────┐
│ ○──○──○──────────────○──○──○  │ ← Lashing rings on both sides
│ │                                  │
│ │                                  │
│ ○──○──○──────────────○──○──○  │
└──────────────────────────────────────┘
  Approximately 6–8 lashing rings per side, load capacity ≥2,000 kg each

V. Container Selection Decision Flow

Does the cargo exceed standard container limits?
    │
    ├── Over-height only (>2.3m) → Open-top container
    │
    ├── Over-height + stacking required → Hard-top container (less common, book early)
    │
    ├── Over-weight (>28 tons) or irregular shape → Flat-rack container
    │
    └── Over-length (>12m) → Flat-rack container (OOG declaration)
            │
            └── Over-length >15m → Charter a vessel (even a flat-rack won't suffice)

VI. Cost Comparison of the Three Container Types (Reference)

The above surcharges do not include out-of-gauge handling fees, lashing fees, or terminal special operation fees. The actual total cost must be confirmed per shipment.

VII. Booking Precautions

Data Note: Cost references are industry average estimates. Actual costs are affected by routing, container availability, and terminal handling charges. Special container surcharges should be confirmed with the shipping line per shipment. Data as of July 2026.

Have over-height/over-weight cargo to ship? Send us your cargo drawings and dimensions, and Bofeng Logistics will help you choose the most cost-effective out-of-gauge cargo transport solution.

Out-of-Gauge Cargo Consultation: info@zhbfwl.com