Lowboy and RGN (removable gooseneck) trailers both exist to haul the heaviest, tallest freight on the road — equipment that a standard flatbed or step deck can’t legally carry because of its height or weight. Both trailer types achieve this with an extremely low deck, but they differ in how that deck connects to the truck, how equipment gets loaded, and how much weight each can legally carry. This page breaks down what each trailer is, how they differ, and how to figure out which one a given heavy-haul shipment actually needs.
What Is a Lowboy Trailer?
A lowboy, sometimes called a fixed-gooseneck (FGN) lowboy, has a gooseneck that is permanently welded to the trailer frame. Because the gooseneck doesn’t detach, equipment is loaded from the rear of the trailer, typically using ramps or lifting equipment rather than driving straight on from the front.[1] The deck itself sits low to the ground — typically 18 to 24 inches — which is what allows a lowboy to carry taller equipment while staying within the legal height limit.[1] A standard lowboy provides roughly 24 to 29 feet of usable deck (“well”) length, and a two-axle lowboy typically supports loads up to around 40,000 pounds, with configurations using additional axles supporting up to roughly 80,000 pounds.[1] Because the gooseneck is fixed rather than hydraulic, lowboys are mechanically simpler, with no detach pins or hydraulic seals to maintain, which generally makes them less expensive to buy and operate than an RGN.[1]
What Is an RGN (Removable Gooseneck) Trailer?
An RGN trailer’s gooseneck detaches and lowers to the ground, turning the front of the trailer into a ramp that equipment can be driven or winched onto directly — a significant advantage for tracked or self-propelled machinery that can’t easily be loaded from the rear.[1] With the gooseneck removed, an RGN’s deck can sit as low as 5 to 6 inches off the ground, lower than a fixed lowboy, which buys back additional height clearance for extremely tall equipment.[1] RGNs also generally offer more usable deck length, typically 29 to 35 feet on a standard unit and up to roughly 53 feet on extended “stretch” RGN configurations, and far more weight capacity — RGNs can be configured with 20 or more axles to legally carry up to roughly 150,000 pounds, compared to a lowboy’s typical 80,000-pound ceiling.[1] That added capability comes at a cost: RGN trailers typically run 30 to 50 percent more expensive than a comparable lowboy, both to acquire and to maintain, due to the hydraulic detach mechanism.[1]
Key Differences at a Glance
- Loading method: Lowboys load from the rear via ramps or lifting equipment. RGNs load from the front, with the detachable gooseneck lowering to create a ground-level drive-on ramp.[1]
- Deck height: Lowboy decks typically sit 18–24 inches off the ground; RGN decks can go as low as 5–6 inches with the gooseneck removed.[1]
- Weight capacity: Lowboys typically max out around 80,000 lbs with additional axles; RGNs can be configured up to roughly 150,000 lbs with 20 or more axles.[1]
- Deck length: Lowboys offer roughly 24–29 ft of well length; standard RGNs offer 29–35 ft, with stretch RGN configurations reaching up to about 53 ft.[1]
- Cost and maintenance: Lowboys are mechanically simpler and generally cheaper to buy and maintain; RGNs cost roughly 30–50% more due to the hydraulic gooseneck mechanism.[1]
How to Decide Which Trailer You Need
The loading method is usually the deciding factor. Tracked or self-propelled equipment that can’t be loaded from the rear — large excavators, dozers, and similar crawler machines — generally needs an RGN, since the detachable gooseneck is often the only practical way to get a machine that can’t climb a steep rear ramp onto the trailer under its own power.[1] Equipment that can be loaded from the rear with ramps or craned into place, and that fits within a lowboy’s roughly 80,000-pound capacity, is often a good fit for a lowboy, particularly when cost is a factor, since lowboys are generally less expensive to source than RGNs. For the heaviest loads — equipment approaching or exceeding 80,000 pounds — an RGN’s higher axle count and weight capacity may be the only trailer that can legally carry the load at all.
Permits and Legal Limits
Both lowboy and RGN shipments are frequently oversize or overweight loads by nature, since the freight they carry is exactly the equipment too tall or too heavy for a standard flatbed or step deck. Oversize and overweight permits are issued at the state level and requirements vary by state along the route, including when a pilot car or escort vehicle is required. Because of this variation, Great Western Transportation reviews the specific states a route crosses before dispatching a truck, for both lowboy and RGN shipments, rather than assuming a single national permit standard applies.
How Great Western Helps You Choose
Great Western Transportation reviews the exact dimensions, weight, and loading method of a heavy-haul shipment before recommending a lowboy or RGN trailer. Accurate dimensions and weight matter most in that decision: if a machine’s height, weight, or loading requirements are reported incorrectly, the wrong trailer type can be dispatched, or a required permit can be missed, leading to delays or a truck that has to be turned around. Every driver and truck is vetted for proper insurance, strong safety ratings, and a clean compliance record before being matched to a shipment. Great Western does not maintain a local terminal or fleet of lowboy or RGN trailers; shipments are coordinated through qualified, vetted carrier partners matched to the specific load, with our team available by phone throughout the process.
Frequently Asked Questions
Which trailer is better for hauling an excavator?
Usually an RGN, since its detachable gooseneck creates a ground-level ramp that lets a tracked excavator drive or winch on directly — something a lowboy’s fixed rear-loading setup can’t do as easily.[1]
Can a lowboy carry the same weight as an RGN?
Not usually. A lowboy typically tops out around 80,000 lbs even with additional axles, while an RGN can be configured with 20 or more axles to legally carry up to roughly 150,000 lbs.[1]
Is an RGN always the better choice?
Not necessarily. RGNs cost more to source and maintain, so for equipment that can be loaded from the rear and fits within a lowboy’s weight capacity, a lowboy is often the more cost-effective option.[1]
Do both trailer types need oversize permits?
Often, yes. Both trailer types are typically used for equipment that is already oversize or overweight, so permit needs are evaluated based on the specific load’s dimensions and weight, not the trailer type itself.
Does Great Western provide both lowboy and RGN trailers?
Yes. Great Western Transportation coordinates both lowboy and RGN shipments through vetted carrier partners matched to the specific equipment, weight, and loading requirements.
Sources
- Lowboy vs. RGN trailer differences: loading method, deck height, weight capacity, deck length, and cost — Differences Between Lowboy and RGN Trailers, Hale Trailer and Lowboy vs RGN Trailer: Key Differences for Heavy Haulers, O Trucking
Request a Lowboy or RGN Trailer Quote
Not sure whether your shipment needs a lowboy or an RGN? Contact Great Western Transportation with your equipment’s dimensions, weight, and loading method, and our team will confirm the right trailer before a truck is dispatched.
Great Western Transportation
5000 Pleasanton Ave Ste 145, Pleasanton, CA 94566
Call Toll Free: 1-800-972-8484
