lowboy trailer with construction vehicles

Step Decks, Lowboys & RGNs – What’s The Difference?

Step Decks, Lowboys & RGNs – What the Heck Are They?

The simple answer: they’re all specialized trailers used for transporting oversized or heavy freight. Step decks, lowboys & RGNs each have their own quirks & features, but generally, all their decks (or beds) are much lower to the ground.

This unlocks 3 major benefits when using any of these trailers:

1. Height Clearance:

Gain an extra few feet in height, which is extremely useful when freight is too tall to be loaded onto a regular flatbed. This provides ample clearance for tall cargo, such as construction machinery, industrial equipment, or large vehicles, ensuring that the cargo can be transported safely without any height-related restrictions.

2. Stability:

The lower deck height of these trailers helps them maintain stability and balance during transportation. It reduces the risk of top-heavy cargo shifting or swaying, enhancing the overall safety of the hauling process.

3. Loading and Unloading:

The low deck height simplifies the loading and unloading process for heavy equipment. It provides a lower incline (or ramp angle), making it easier to drive machinery onto or off the trailer. This feature is particularly beneficial for equipment with low ground clearance or those requiring specialized loading/unloading equipment.

Now that you’re up to speed on the overall benefits of step decks, lowboys & RGNs, we’re going to talk about each of them, what makes them special and common examples of freight they’re used for.

So without wasting any more time, let’s get into it!

Step Decks

So the first thing when comparing step decks, lowboys & RGNs is understanding what an ordinary step deck is.

Also known as drop decks, single-drops or step frames. Step decks have a lower deck height compared to standard flatbed trailers. They feature a lower deck at the back and a higher deck at the front, creating a step-like configuration. This means that freight laid on the main bed of the trailer can have a max height of 10′ 2″ of compared to just 8′ 6″ on a regular flatbed.

If you’d like to learn more about the sort of freight often used on flatbeds, we’ve written a helpful article comparing them to conestogas.

step decks used for carrying large piece of construction material

Step Deck trailer carrying a large piece of construction material

Key facts:

  • Lower deck height at the back and higher deck at the front.
  • Can accommodate taller cargo while maintaining a lower overall trailer height.
  • 10′ 2″ max height for freight
  • Weight rating typically ranges from 20,000 to 48,000 pounds.

What sort of freight would require a step deck?

  • Heavy machinery such as bulldozers, excavators, or forklifts
  • Construction materials like steel beams, pipes, or concrete panels
  • Oversized equipment or components for wind turbines or solar panels
  • Agricultural equipment such as tractors or harvesters
  • Large vehicles like buses, motorhomes, or military vehicles


Lowboy trailers, also known as low loaders, double decks or double drops are designed with an extremely low deck height. These are designed for some of the tallest freight you can transport by road. Being only 18″ off the ground means that freight on lowboy trailers can have a max height of 11′ 6″ instead of just 10′ 2″ on a regular step deck trailer.

A common question we often hear at PEI is:

“There’s less height on a step deck, why wouldn’t I just use a lowboy everytime?”

And the answer is this: unless you NEED the extra 1′ 4″ provided by a lowboy, you’re going to be better off opting for a step deck. Lowboys are more expensive to operate than step decks and you’ll likely end up paying more for a lowboy.

Lowboy trailer pulling heavy equipment













Lowboy trailer pulling heavy equipment

Key facts:

  • Extremely low deck height
  • Ideal for hauling heavy and oversized equipment
  • 11′ 6″ max height for freight
  • Weight rating typically ranges from 40,000 to 80,000 pounds

What sort of freight would require a Lowboy?

  • Oversized construction machinery such as cranes, backhoes, or pavers
  • Mining equipment like dump trucks, loaders, or drilling rigs
  • Large industrial machinery such as generators or compressors
  • Heavy vehicles including excavators, road rollers, or concrete mixers
  • Off-road vehicles like large trucks or specialized off-highway equipment



RGN trailers, also referred to as removable gooseneck trailers (or just goosenecks) have a detachable front section called a…

You guessed it!

A gooseneck.

This detachable section allows for easy loading and unloading of cargo. The gooseneck is attached to the towing vehicle and can be hydraulically raised and detached, creating a ramp for loading equipment onto the trailer. You often find this useful when the freight needs to be carefully unloaded.

Oftentimes, you’ll find the term RGN is used only to describe the removable gooseneck aspect of the trailer, but in most cases an RGN is essentially a lowboy trailer that can be detached from the front. Whereas a standard lowboy cannot.

RGNs are commonly used for transporting heavy and oversized loads that require specialized equipment for loading and unloading, such as construction machinery or industrial equipment.

At PEI, we’re no stranger to RGNs. In fact we used one to transport a live whale through downtown Atlanta!

The flexibility of the RGN meant that the folks at Georgia Aquarium could have their whale delivered right to their back-entrance where they safely unloaded the animal.

RGN trailer being used to transport a whale
PEI Transporting a whale on an RGN for Georgia Aquarium

Generally speaking, the heavier and larger the cargo, the more likely you’ll need to use an RGN.

Key facts:

  • Detachable front section called a gooseneck
  • Very low ramp angle perfect for loading & unloading freight with little ground clearance
  • Used for transporting extremely heavy and oversized loads
  • Weight rating starts from 40,000 pounds and can exceed 150,000 pounds

What sort of freight would require an RGN?

  • Extremely heavy construction machinery like cranes or heavy-duty excavators.
  • Industrial equipment such as transformers, turbines, or refinery components.
  • Oil and gas industry equipment like drilling rigs or pipeline sections.
  • Oversized vessels or tanks for chemicals, liquids, or gases.
  • Large-scale infrastructure components like bridge beams or trusses.




Need help with your tall & oversized shipments?

At PEI we’re experts in dealing with specialized freight and can handle yours with any custom requirements.

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