Types of Lowboy Trailers: Fixed Gooseneck, Hydraulic & Mechanical Detach
There are three main types of lowboy trailers, each defined by its gooseneck design: fixed gooseneck (FGN), hydraulic removable gooseneck (hydraulic RGN), and mechanical removable gooseneck (mechanical RGN). The gooseneck type determines how equipment is loaded, how much the trailer weighs, what it costs to buy and maintain, and what types of hauling jobs it is best suited for. This guide breaks down all three types so you can make an informed decision.
FGN
Simplest & Lightest
Hydraulic RGN
Most Popular
Mechanical RGN
Lowest Maintenance
Ahmad Qazi
Founder & CEO, O Trucking LLC
Fact-Checked by O Trucking Dispatch Team
5+ years coordinating heavy haul loads with all lowboy types, managing equipment transport logistics, and advising carriers on trailer purchases
Written by Ahmad Qazi, founder of O Trucking LLC, drawing on 9+ years dispatching for owner-operators. Learn more about us.
O TruckingTypes of Lowboy Trailers: Fixed Gooseneck, Hydraulic & Mechanical Detach (2026)
Three Types of Lowboy Trailers
All three lowboy types share the same fundamental double-drop design: a gooseneck that connects to the tractor, a lowered well where cargo rides, and a rear axle assembly. The difference is entirely in the gooseneck section — specifically, whether it is permanently attached or removable, and if removable, how the detach mechanism works.
Each type has clear strengths and limitations. Understanding them helps you choose the right trailer for your operation — or, if you are a shipper, helps you understand what your carrier is using and why it matters for your load.
Key Takeaways
- Lowboy types differ only in the gooseneck: fixed (FGN), hydraulic removable (RGN), or mechanical removable (RGN).
- FGN is the lightest and cheapest but cannot drive-on load — it needs a crane or rear ramps.
- Hydraulic RGN is the most popular type: drive-on loading, a 5-15 minute detach, and well lengths up to ~53 feet.
- Mechanical RGN also drives on but detaches slower (15-30 minutes) with no hydraulics to fail or service.
- Match the type to your loads: crane-loaded non-mobile freight favors FGN; self-propelled equipment favors an RGN.
If you are still deciding between a non-detachable and a detachable deck, our lowboy vs RGN comparison and the how an RGN gooseneck works guide walk through the mechanics in more detail.
1. Fixed Gooseneck (FGN)
A fixed gooseneck lowboy has the gooseneck permanently welded to the trailer frame. It cannot be removed or detached. Equipment must be loaded from the side using a crane or from the rear using ramps.
FGN Specifications
Well Length: 24-29 feet
Tare Weight: 15,000-20,000 lbs
Used Price: $45,000-75,000
Loading: Crane or rear ramps
Maintenance: $2,000-4,000/year
Moving Parts: Minimal
FGN Advantages
Lowest purchase cost — $20,000 to $45,000 less than a comparable RGN
Lightest tare weight — 3,000 to 6,000 pounds lighter, giving more payload capacity
Lowest maintenance — No hydraulics or detach mechanism to maintain
Most structurally rigid — Permanent gooseneck creates strongest frame connection
FGN Limitations
Requires crane access — Cannot load self-propelled equipment from the front without a crane or ramps
Shorter well length — 24-29 feet limits the size of equipment that can be hauled
Less versatile — Cannot accept loads at sites without crane access
2. Hydraulic Removable Gooseneck (Hydraulic RGN)
The hydraulic RGN is the most popular lowboy type for heavy equipment hauling. The gooseneck detaches using hydraulic cylinders, which are powered by the tractor's PTO (power take-off) or a dedicated hydraulic pump. When detached, the front of the trailer drops to ground level, creating a ramp for equipment to drive directly onto the deck.
Hydraulic RGN Specifications
Well Length: 29-53 feet
Tare Weight: 18,000-26,000 lbs
Used Price: $65,000-120,000
Loading: Front drive-on, crane, or ramps
Maintenance: $4,000-8,000/year
Detach Time: 5-15 minutes
Hydraulic RGN Advantages
Drive-on loading — Equipment drives directly onto the deck from the front. No crane needed for self-propelled equipment.
Fast detach/attach — Hydraulic operation takes 5 to 15 minutes, much faster than mechanical RGN
Longer well length — 29 to 53 feet of usable deck accommodates longer equipment
Most versatile — Can load from front (drive-on), side (crane), or rear (ramps)
Hydraulic RGN Limitations
Highest purchase cost — $65,000 to $120,000 used, $110,000 to $200,000+ new
Highest maintenance cost — Hydraulic cylinders, seals, hoses, and fluid require regular service
Heaviest tare weight — 18,000 to 26,000 lbs reduces available payload capacity
Hydraulic failure risk — A broken hydraulic line or cylinder during loading can strand equipment mid-ramp
3. Mechanical Removable Gooseneck (Mechanical RGN)
The mechanical RGN uses manual pins, latches, and mechanical linkages instead of hydraulics to detach the gooseneck. The operator physically removes pins and uses the tractor's movement to separate the gooseneck from the trailer. The detach process is slower and more labor-intensive than hydraulic RGN but simpler mechanically.
Mechanical RGN Specifications
Well Length: 29-40 feet
Tare Weight: 17,000-23,000 lbs
Used Price: $50,000-90,000
Loading: Front drive-on, crane, or ramps
Maintenance: $2,500-5,000/year
Detach Time: 15-30 minutes
Mechanical RGN Advantages
Drive-on loading capability — Same front-loading advantage as hydraulic RGN
No hydraulic components — Eliminates hydraulic failure risk, leaks, and fluid maintenance
Lower maintenance than hydraulic — Mechanical components are simpler and cheaper to service
Mid-range pricing — $15,000 to $30,000 less than comparable hydraulic RGN
Mechanical RGN Limitations
Slower detach/attach — 15 to 30 minutes per cycle, compared to 5 to 15 minutes for hydraulic
More physical effort — Manually pulling pins and positioning the tractor requires operator strength and experience
Less common in market — Fewer models available, harder to find parts, fewer mechanics experienced with the mechanism
Full Comparison Table
| Feature | FGN | Hydraulic RGN | Mechanical RGN |
|---|---|---|---|
| Drive-On Loading | No | Yes | Yes |
| Detach Time | N/A | 5-15 min | 15-30 min |
| Well Length | 24-29 ft | 29-53 ft | 29-40 ft |
| Tare Weight | 15-20K lbs | 18-26K lbs | 17-23K lbs |
| Used Price | $45-75K | $65-120K | $50-90K |
| Annual Maintenance | $2-4K | $4-8K | $2.5-5K |
| Popularity | Moderate | Most popular | Least common |
How to Choose the Right Type
The right lowboy type depends on your operation's specific needs. Here is a decision framework:
Choose FGN if...
- - You always have crane access at pickup and delivery
- - You haul primarily non-mobile equipment (transformers, generators)
- - You need maximum payload capacity (every pound matters)
- - Budget is the primary decision factor
- - You want the simplest possible maintenance profile
Choose Hydraulic RGN if...
- - You haul self-propelled equipment (excavators, bulldozers, loaders)
- - You load at construction sites, farms, or remote locations
- - Loading speed matters for your operation
- - You need the longest possible well length
- - You want maximum versatility for accepting diverse loads
Choose Mechanical RGN if...
- - You want drive-on loading but prefer simpler maintenance
- - You operate in remote areas where hydraulic repair is unavailable
- - Loading speed is important but not the top priority
- - You want a middle-ground option on price and capability
The Market Has Spoken: Hydraulic RGN Leads
Don't buy on detach speed alone
Frequently Asked Questions
What is the difference between FGN and RGN lowboy trailers?
A fixed gooseneck (FGN) is permanently welded to the trailer and must be loaded from the side or rear with a crane or ramps. A removable gooseneck (RGN) detaches so the front of the deck drops to the ground, letting self-propelled equipment drive on. RGNs come in hydraulic and mechanical detach versions.
Which type of lowboy trailer is most popular?
The hydraulic removable gooseneck (hydraulic RGN) is the most common lowboy for heavy equipment hauling. It combines drive-on loading, a fast 5-15 minute detach, and the longest well length (up to about 53 feet), which makes it the most versatile choice for construction and site work.
Is a hydraulic or mechanical RGN better?
Choose a hydraulic RGN for speed and versatility — it detaches in 5-15 minutes and loads almost anything. Choose a mechanical RGN if you want lower maintenance and no hydraulic failure risk in remote areas, accepting a slower 15-30 minute, more labor-intensive detach.
Which lowboy type carries the most payload?
The fixed gooseneck (FGN) typically carries the most payload because it is the lightest, with a tare weight around 15,000-20,000 lbs — roughly 3,000 to 6,000 lbs lighter than a comparable hydraulic RGN. Less trailer weight means more legal cargo weight before you hit axle and gross limits.
Want to see how a detachable deck is loaded step by step? Read our how to load a lowboy trailer walkthrough.
How Our Team Manages Lowboy Logistics
At O Trucking LLC, we dispatch across all three lowboy types and match the right trailer to each load. We consider equipment weight, dimensions, loading site conditions, and route requirements when recommending a carrier. Whether your load needs an FGN with crane service or an RGN for drive-on convenience, we coordinate the entire process. See our lowboy trailer glossary page for the complete reference.
Need Heavy Haul Dispatch with the Right Equipment?
Our team matches your load to carriers with the right lowboy type — FGN, hydraulic RGN, or mechanical RGN — based on your equipment, site conditions, and budget.