20ft Flat Rack Container Guide: Dimensions & OOG Cargo Shipping

Sometimes, your cargo simply won't fit inside a box. Whether it is too wide, too tall, or too heavy, standard containers have their limits. That is where the 20ft Flat Rack comes in.

Visible in the TraceContainer.com system simply as "20 Flat Rack", this is the industry standard for "Out of Gauge" (OOG) and heavy-lift shipments. Unlike a standard box, it has no side walls and no roof—just a reinforced floor and two end walls.

This guide explains when to use a Flat Rack and the critical dimensions you need to know for planning.

What is a Flat Rack Container?

A Flat Rack is designed for heavy loads and over-dimensional cargo. It consists of a steel frame with a thick wooden floor and two end walls (bulkheads).

• No Roof/Sides: This allows you to load cargo from the top (using a crane) or from the sides (using a forklift).

• OOG Capable: If your cargo sticks out past the width or height of the container, it is classified as Out of Gauge (OOG). Flat racks are the only containers that can legally carry OOG cargo.

Fixed vs. Collapsible

In booking menus, you might see "Flat Rack" and "Collapsible Flat Rack."

• Fixed End: The end walls are rigid and cannot move. These are stronger but harder to transport when empty.

• Collapsible: The end walls fold down flush with the floor. This allows carriers to stack empty flat racks (bundles) to save space on the return trip.

Best Uses: Heavy & Oversized

The 20ft Flat Rack is a beast when it comes to weight. Because it doesn't have the steel weight of walls and a roof, it has a massive payload capacity.

Typical Cargo:

1. Heavy Machinery: Generators, turbines, transformers.

2. Construction Equipment: Excavator parts, bulldozers.

3. Industrial Parts: Giant valves, steel coils, metal sheets.

4. Vehicles: Trucks or boats that are too wide for a standard container.

20ft Flat Rack Dimensions

Note: Flat racks have a higher floor than standard containers to support the weight, so the vertical space is slightly less.

Critical Note: The "Internal Width" is the distance between the bottom rails. However, since there are no walls, your cargo can exceed this width (OOG), but you will pay extra surcharges for the "lost slots" on the ship next to your container. 

Securing the Load (Lashing)

Shipping on a Flat Rack carries higher risk because the cargo is exposed to the elements (wind, waves, rain).

• Lashing Points: 20ft Flat Racks are equipped with heavy-duty lashing rings along the bottom rail.

• Requirement: Cargo must be chained and strapped down by professional lashing teams. If the cargo is not secured properly, the port captain will reject the shipment.

Track Your OOG Shipment

High-value machinery requires high-visibility tracking. Don't lose sight of your project cargo. Trace your Flat Rack container globally with TraceContainer.com.

> Track My Flat Rack