Equipment Guides
What Is Step Deck Freight?
A step deck, or drop deck, trailer has a lower main deck that lets taller freight stay within legal height limits. Learn how step decks work and when to use one.
By Customer First Brokerage · · 5 min read
Step deck freight is freight moved on a step deck trailer — an open-deck trailer with two levels. A short upper deck sits over the tractor's fifth wheel, and a longer main deck “steps down” behind it, closer to the ground. The trailer is also called a drop deck. Shippers use it for freight that is too tall for a standard flatbed but does not require a specialized low-boy trailer.
How a step deck is laid out
On a typical 48-foot step deck, the upper deck is about 10 to 11 feet long and the lower deck makes up the remaining 37 to 38 feet. On a 53-foot trailer the lower deck is roughly 42 to 43 feet. The upper deck sits at about the same height as a flatbed, around 5 feet. The lower deck typically sits around 36 to 42 inches off the ground.
Why the lower deck matters
Most states set a legal overall height of 13 feet 6 inches to 14 feet 6 inches. Subtract a flatbed's 5-foot deck from 13 feet 6 inches and you have about 8 feet 6 inches of room for freight. Subtract a step deck's roughly 3.5-foot lower deck and you have about 10 feet. Those extra 18 inches or so are often the difference between a legal load and one that needs an over-height permit.
| Trailer | Deck height | Room for freight |
|---|---|---|
| Flatbed | ≈ 60 in | ≈ 8 ft 6 in |
| Step deck (lower deck) | ≈ 36–42 in | ≈ 10 ft |
| RGN (well) | ≈ 18–24 in | ≈ 11 ft 6 in – 12 ft |
What ships on a step deck
- Machinery and industrial equipment
- Tractors, farm implements and smaller construction equipment
- Tall crates, tanks and fabricated structures
- HVAC units and mechanical systems
- Vehicles and equipment that can be driven up ramps
Loading a step deck
Like a flatbed, a step deck can be loaded from the side or from above by forklift or crane. Many step decks also carry loading ramps, which let wheeled or tracked equipment be driven onto the lower deck. If you plan to drive equipment on, say so when you request a quote so the carrier arrives with ramps.
When a step deck is not enough
If freight is taller than about 10 feet, heavier than a step deck can legally carry, or must be driven onto a very low deck, the next option is usually a removable gooseneck trailer. See What Is an RGN Trailer? for how those compare.
