Why flat racks will be so important in 2025

Large machinery, boats or oversized pallets – when cargo does not fit into a standard container, the flat rack (FR) becomes the preferred solution. With a sturdy floor, two end walls (hinged or fixed) and no side walls, it is ideal for out-of-gauge shipments. Knowing the exact dimensions and weights saves time, money and hassle. This guide provides you with the most important data, practical tips and checklists.

Flat rack: overview of designs, uses and limitations

designs

• Collapsible EndsFoldable front walls, space-saving when empty, versatile.
• Fixed Ends: Fixed end walls often have a higher load capacity, but are less flexible for return transport.
• 40′ high cube flat rack: Higher construction (9′6″), specific to shipping companies, relevant for stowage heights and lashings.

Typical applications

• Extra-wide machines
• Excess height (e.g. generators)
• Heavy goods with concentrated loads (e.g. construction machinery)
• Rollable units (only with suitable lashing points)

Important: Load capacities vary depending on the shipping company and year of manufacture. For 20′ FRs, MGWs of up to 45,000 kg are common, and for 40′ FRs, up to 60,000 kg – the payload is always MGW minus tare weight.

Standardised external dimensions according to ISO

ISO 668 specifies the external dimensions of containers: 20′ or 40′ length, 8′ width, 8′6″ height. Flat racks follow these dimensions to ensure stackability and craneability. However, the internal dimensions vary depending on the end wall type and floor frame.

Typical flat rack dimensions and weights

Typical values (bandwidths per carrier):

20′ flat rack
External dimensions: 6.058 × 2.438 × 2.591 m
Internal dimensions: approx. 5.94 × 2.35 × 2.15–2.30 m
MGW: up to 45,000 kg
Tare weight: ~4.8–5.5 t
Payload: ~30–40 tonnes

40′ flat rack
External dimensions: 12,192 × 2,438 × 2,591 m
Internal dimensions: approx. 11.7–12.0 × 2.35 × 1.95–2.30 m
MGW: up to 60,000 kg
Tare weight: ~5.5–6.5 t
Payload: ~35–39 tonnes

Understanding MGW, tare weight, payload and ground load

• MGW (Maximum Gross Weight): Maximum weight including tare
• Tara: Net weight of the empty flat rack
• Payload: MGW minus tare
• Floor load/point load: Critical with concentrated loads – always distribute and secure

Tip: For point loads such as wheel loaders, use load distribution plates and secure the load in accordance with the CTU Code.

Calculating out-of-gauge (OOG) shipments correctly

• Extra width: Over 2,438 metres, depending on terminal and routing
• Excess height: Possible, but limited by header, lash options and route
• Excess length: Pay attention to front walls, especially with collapsible versions.
• Routing: → Timetables

Packing & Securing according to CTU Code

The CTU Code is the international standard for the safe packing of container cargo units. It is also mandatory for flat racks.

Important principles

1. Weight distribution: Centre of gravity
2. Laschung: Only tested equipment (chains, belts, wire ropes)
3. Protective measures: Edge protectors, anti-slip mats
4. Documentation: Packing list, photographic evidence, certificates

→ Further information: IMO - CTU Code

Practical examples of flat rack cargo

• Construction machinery: Distribute wheel loads, choose the right chains
• Tractor units: Alternative to RoRo shipping → What do I need to bear in mind for a RoRo shipment?
• Yachts/boats: Spreader bars, keel supports, check height
• Steel modules: Note tipping moments and contact surface

Decision-making aid: Flat rack vs. RoRo vs. Open top

Checklist: 10 steps to secure flat rack booking

First of all:

1. Exact dimensions & weight including attachments
2. Document centre of gravity & load points
3. Check lashing points on the load
4. Check routes & timetables → Timetables
5. Clarify insurance

When packing:

6. Check & distribute floor load
7. Create lashing plan with lashing equipment (SWL, LC)
8. Comply with CTU code + photo documentation

In the harbour:

9. Check gate-in time slot & equipment ID
10. Enter B/L data correctly

Note: Prices depend on the relationship, equipment, OOG dimensions and season – please request an individual quote for exact figures.

FAQ: Frequently asked questions

Which flat rack dimensions are binding?
Only the data for the flat rack actually provided (equipment sheet) is binding. ISO 668 only defines the external dimensions.

How high can I build on a flat rack?
Varies depending on route, header, CTU code and terminal conditions. Always check individually.

How much can a flat rack carry?
20 to 45 tonnes MGW, 40 to 60 tonnes MGW. The actual usable payload is usually 30–40 tonnes.

Why are point loads critical?
Because they can cause local overloads. Distribute the load and secure it in accordance with the CTU Code.

Which is better – RoRo or flat rack?
RoRo is ideal for roadworthy units. Flat racks are better for oversized or non-roadworthy cargo. → What do I need to bear in mind for a RoRo shipment?

Conclusion: Success with data, CTU code and the right setup

Flat rack shipping requires precise measurements, CTU code-compliant securing, correct documentation and early planning. With this knowledge, project cargo can be handled safely and efficiently.

Disclaimer: All information in this article has been carefully researched but is subject to change at any time. ODS Orient accepts no liability for the topicality, accuracy and completeness of the information provided.