Flatbed vs Lowboy vs RGN: Choosing the Right Trailer for Your Equipment
One of the most common questions equipment shippers ask is: 'What kind of trailer do I need?' The answer depends on three factors: how tall your equipment is in transport position, how heavy it is, and how it needs to be loaded. Choosing the wrong trailer type can result in height violations, loading damage, or unnecessary permit costs. This guide breaks down the four main open-deck trailer types used in heavy equipment transport and explains exactly when to use each one.
The Four Main Trailer Types for Heavy Equipment
Open-deck trailers used for heavy equipment transport fall into four main categories, each with different deck heights, weight capacities, and loading methods:
1. Flatbed Trailer
A standard flatbed trailer has a deck height of approximately 5 ft off the ground. The deck is flat with no drop sections, and loading is done from the side (via crane or forklift) or from the rear via ramps.
- Max legal height: 8.5 ft (13.5 ft total loaded height minus 5 ft deck = 8.5 ft machine height)
- Typical payload: 48,000 lbs on a 48 ft trailer
- Best for: Compact equipment, attachments, generators, compressors, and any machine under 8.5 ft tall that can be crane-loaded or driven up a ramp
- Not ideal for: Self-propelled equipment with low ground clearance (ramp angle can cause high-centering), or equipment over 8.5 ft tall
2. Step-Deck (Drop Deck) Trailer
A step-deck trailer has two deck levels: a short upper deck (approximately 5 ft high) and a longer lower main deck (approximately 3.5 ft high). The lower deck provides extra height clearance compared to a flatbed.
- Max legal height on lower deck: Approximately 10 ft (13.5 ft total minus 3.5 ft deck)
- Typical payload: 42,000–48,000 lbs
- Best for: Equipment that is too tall for a flatbed but can still be crane-loaded — telehandlers, mid-size forklifts, compact track loaders, boom lifts
- Not ideal for: Very heavy equipment or self-propelled machines that cannot be safely loaded via rear ramps
3. Lowboy Trailer (Fixed Neck)
A lowboy trailer has a very low well section (approximately 18–24 inches off the ground) that provides maximum height clearance. The gooseneck is fixed — it does not detach. Loading is done from the rear via ramps or from the side via crane.
- Max legal height: Approximately 11.5–12 ft (13.5 ft total minus 18–24 in deck)
- Typical payload: 40,000–80,000 lbs depending on axle configuration
- Best for: Tall, heavy equipment that does not need front-loading — large generators, transformers, and equipment that can be safely loaded via rear ramps
- Not ideal for: Self-propelled equipment with very low ground clearance that would high-center on rear ramps
4. RGN (Removable Gooseneck) Trailer
An RGN trailer is a lowboy with a detachable gooseneck. When the gooseneck is removed, the front of the trailer drops to ground level, creating a ramp that allows self-propelled equipment to drive on from the front. This is the safest loading method for tracked equipment and machines with low ground clearance.
- Max legal height: Approximately 11.5–12 ft (same as lowboy)
- Typical payload: 40,000–130,000 lbs; multi-axle configurations can handle up to 200,000 lbs with permits
- Best for: Excavators, dozers, motor graders, cranes, and any self-propelled machine that would high-center on rear ramps
- Cost: Generally the most expensive trailer type due to specialized equipment and higher permit likelihood
Quick Decision Guide
| Equipment Type | Recommended Trailer |
|---|---|
| Compact equipment, attachments, generators under 8.5 ft tall | Flatbed |
| Telehandlers, boom lifts, mid-size forklifts (8.5–10 ft tall) | Step-Deck |
| Large generators, transformers, non-self-propelled heavy equipment | Lowboy |
| Excavators, dozers, motor graders, cranes (self-propelled) | RGN |
| Very heavy loads over 80,000 lbs payload | Multi-axle RGN or specialized trailer |
How Loading Method Affects Trailer Choice
The loading method is often the deciding factor between a lowboy and an RGN. If a crane is available at the pickup location, a fixed-neck lowboy may be sufficient even for heavy self-propelled equipment. If no crane is available and the machine must drive on under its own power, an RGN is almost always the right choice. RGNs also require more space ahead of the trailer to drop the neck — tight job sites or auction yards with limited space may favor rear-loading trailers.
Permit Implications of Trailer Choice
Trailer choice affects permit requirements. Flatbeds and step-decks keep most equipment within legal height limits, reducing permit costs. Lowboys and RGNs are lower to the ground, which helps with height, but the machines loaded on them are often heavier and wider, increasing the likelihood of overweight and oversize permits. IronHaul reviews each load's specific dimensions and weight to recommend the most cost-effective trailer type.
Not sure which trailer your equipment needs? IronHaul Logistics will review your equipment specs and recommend the right trailer type for your move. Call (208) 495-2260, email [email protected], or request a free quote online.
Common questions
What is the difference between a lowboy and an RGN trailer?
Both are low-deck trailers with similar height clearance. The key difference is loading method: a lowboy has a fixed gooseneck and loads from the rear via ramps or crane. An RGN has a detachable gooseneck that drops to ground level, allowing self-propelled equipment to drive on from the front.
When should I use a step-deck instead of a flatbed?
Use a step-deck when your equipment is between 8.5 ft and 10 ft tall in transport position. The lower main deck of a step-deck provides approximately 18–24 inches of additional height clearance compared to a standard flatbed.
Can an excavator be shipped on a flatbed?
Most full-size excavators are too tall and too heavy for a standard flatbed. Excavators typically require a lowboy or RGN trailer. Mini excavators under 8.5 ft tall and within legal weight limits can sometimes be shipped on a flatbed or step-deck.
How much weight can an RGN trailer carry?
Standard RGN trailers handle 40,000–130,000 lbs. Multi-axle RGN configurations with additional flip or booster axles can handle up to 200,000 lbs with proper overweight permits.
Does trailer type affect permit requirements?
Yes. Trailer choice affects total loaded height and GVW, which determines permit requirements. IronHaul reviews each load's specific dimensions and weight to recommend the most cost-effective trailer type and identify any permit requirements.
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