A double drop trailer (also known as the lowboy or RGN) is a specialized trailer with a unique design. These trailers either possess a fixed gooseneck or a removable gooseneck. This trailer is used in the transportation of heavier loads that cannot be shipped otherwise.
In this article, we will explore in detail the double drop trailer dimensions, their features, types, and when it is recommended to use them.
What Is a Double Drop Trailer?
A double drop trailer is a kind of flat deck trailer that possesses a long narrow gooseneck trailer hitch. The term double is basically to signify two low points that exist in the middle of the axles. The trailer’s front is higher in size than the back giving appropriate height clearance. The trailer’s structure is built in a way that a lower deck section is present in the middle of the first trailer axle and the gooseneck.
These trailers are built with steel, aluminum, or both:
Steel is an ideal choice for the main structural parts of the trailer because of its durability and strength. However, steel is prone to corrosion which means frequent maintenance is required especially when the trailer is used in extreme weather conditions.
Aluminum is lighter in weight which decreases the overall weight of the trailer. This makes it possible to carry even heavier loads without exceeding weight restrictions. Moreover, Aluminum is durable and less prone to corrosion, making it ideal for transportation in harsh weather conditions.
Specifications of Double Drop Trailers
These trailers have a unique design where their cargo beds can move as low as 18 to 24 inches. They consist of three main parts that include:
Front deck – raised and attached to the truck.
Main deck – the lower part of the trailer, which, in some cases, can be extended as needed.
Rear deck – the end part, and it is built longer in height than the well but is still shorter than the front deck.
Types of Double Drop Trailers
Even though many names in this list are used interchangeably, all types have some unique features. Let’s explore the different types of these trailers in detail:
Removable Gooseneck Trailer (RGN)
RGN, short for removable gooseneck, can be detached and connected to the well to create a ramp. This feature helps in the easy loading of the cargo in case of extremely heavy machinery. Equipment like bulldozers and excavators are simply driven on the ramp towards the well inside the trailer.
Fixed Gooseneck Trailer
Fixed gooseneck, as the name suggests, is attached permanently to the well. This gives better stability to the trailer and is used for certain types of loads especially when front loading is not required. The Gooseneck can also carry heavier weights than a fifth wheel and the gooseneck attachment takes up less space so there is a more free area in the deck region.
Double Drop Trailer
Double drop trailers are different from other trailers by having a double dip in the deck region. They are similar in build to the RGN trailers, however, the gooseneck can be fixed or removable. These trailers possess a slightly less weight capacity in comparison to RGN, however, with the use of more axles, this feature can be improved.
Lowboy Trailer
Even though the names lowboy trailer and double drop trailers are interchangeably used, the lowboy is different because it has the lowest drop in the deck. This makes it ideal for transporting very tall equipment. Both removable and nonremovable hitches are used with it, making the process of loading easier.
|
Feature |
Fixed Gooseneck Trailer (FGN) |
Lowboy Trailer |
Double Drop Trailer |
|
Gooseneck |
Fixed, not removable |
Usually removable |
Fixed or removable |
|
Deck Design |
Single continuous deck |
Extremely low single-deck |
Two drops with a low center well |
|
Deck Height |
Higher than lowboy and double-drop |
Lowest deck height |
Low middle deck, higher ends |
|
Primary Use |
Standard tall or heavy cargo |
Very tall and heavy equipment |
Oversized, tall loads with special clearance needs |
|
Front Loading |
Not possible |
Possible (removable gooseneck) |
Possible (if RGN), not always |
RGN VS Lowboy: Dimensions
Apart from design differences, RGN and Lowboy have structural differences as well. We will explore them in detail below:
|
Type of Trailer |
Max Legal Acceptable Weight (in lbs) |
Max Legal Acceptable Dimensions (in ft) l/w/h |
Front Deck Dimensions (in ft) l/w/h |
Rear Deck Dimensions (in ft) l/w/h |
|
RGN |
44,000 |
29/ 8.5/ 12 |
10/ 8.5/ 8.5 |
9/ 8.5/ 10 |
|
Lowboy |
45,000 |
29/ 8.5/ 11.5 |
10/ 8.5/ 8.5 |
9/ 8.5/ 10 |
When Should You Use a Double Drop Trailer?
Double drop trailers are needed for a variety of reasons, amongst which the most obvious is when you want to transport equipment that is taller but under the 12 ft limit. The cargo bed of these trailers is as low as 18 inches off the ground, proving to be a very suitable transport for extra tall loads. Let’s explore more about these double drop trailer uses below:
Load Is Large and Heavy
One of the key benefits of this trailer’s design is the reduced risk of toppling. Its structure is specifically engineered to address the challenges of transporting large and heavy cargo. The center of gravity plays a critical role here—by incorporating a drop in the deck between the gooseneck and the first trailer axle, the cargo sits much lower to the ground. This low center of gravity enhances stability, keeping the load secure and less likely to tip over.
Tall and heavy loads carry a higher risk of instability, especially during sharp turns, on uneven roads, or in extreme windy conditions. Nevertheless, this trailer’s design mitigates that risk by keeping the load close to the ground, making sure stability and safety throughout the journey.
Load Is Tall
When you put a tall load in a standard flatbed truck, it poses a problem during transportation through normal routes which have height restrictions for bridges and tunnels since it can transport around 8.5 ft of cargo. This leads to the use of other longer routes which results in inefficient operational costs.
This situation is avoided when you use a trailer as mentioned above as well. Since the trailer’s cargo body is very low to the ground, this increases the height clearance by about 12 ft. You can easily transport much taller equipment saving fuel costs with a shorter delivery time.
Cargo Has to Be Loaded by a Crane
The central well of the double drop trailer is built lower than the rest of its structure. This is especially helpful when you have to load the cargo using a crane since the items can be lowered with ease, making the process safer in comparison to loading cargo in other kinds of trailers. Yet, you have to carefully plan for this process to work efficiently. Some important things to consider are:
The stability and balance of both the cargo and the trailer have to be maintained. The weight of the load should be evenly distributed so that it does not tip over or shift while putting it in the trailer well.
The structure of the trailer requires precise placement of the cargo within the well. This is especially true for irregularly shaped equipment.
The load has to be secured properly by using tie-downs as well as load securement techniques. So the load is stationary in the trailer throughout the journey.
Skilled professionals who are proficient in handling heavy equipment with the use of a crane while also being familiar with the trailer’s structure are required for this task.
Load Is Resistant to Harsh Conditions
If you have equipment that can withstand harsh environments such as construction machinery and industrial equipment, then a double drop trailer is a good choice for your transportation.
Conclusion
To sum up, double drop trailers are important for transporting necessary heavy machinery and equipment to their destination. There are four types of this trailer such as the RGN, fixed gooseneck trailer, double drop and lowboy trailer. These trailers are designed to transport your goods that are tall, heavy, irregularly shaped and resistant to harsh environments.
FAQs
Are there any double drop deck trailer variations?
Various drop deck trailer trucks exist for the transportation of heavy load shipping. A drop deck trailer (also known by the name step deck trailer) has been designed to transport tall loads within legal height limits. They can carry cargo of up to 48,000 pounds.
What is a flatbed trailer?
It is defined as an open deck equipment that has neither roof nor sides. It is used for the transportation of heavy and oversized machinery. The flat shape of the trailer makes loading and unloading items extremely easy.
