WHAT ARE THE DIFFERENT TYPES OF SEMI-TRAILERS?

Choosing the right type of semi-trailer is essential in the transportation industry to ensure safety and efficiency for every shipment. Each semi-trailer, from container chassis to lowboys and specialized models, offers unique benefits for various transportation needs. In this article, Thaco Trailers will delve into the various types of semi-trailers, highlighting their key specifications and the advantages they offer for different logistics requirements.

1. What are the different types of semi-trailers?

1.1 Intermodal chassis (Container chassis):

• Standard chassis

The standard chassis is the most common container chassis used in the industry. It is designed to carry 20 and 40-foot containers and is typically used for general freight. The simplicity and widespread use of the standard chassis make it a reliable choice for many businesses. These chassis are also available in various lengths to accommodate different container sizes.

• Extendable chassis

The extendable chassis is designed to carry containers of varying lengths, ranging from 20ft to 53ft long tunnels. Its ability to adjust its length makes it perfect for carrying containers of various sizes, including 20ft, 40ft, 45ft, and 53 ft containers. Therefore, you can simply change the container lock positions for the best fit and load distribution.

• Slider chassis

Slider chassis are versatile options that allow for the adjustment of the container’s position on the chassis. This feature is particularly useful when balancing the weight distribution of the cargo, ensuring safer and more efficient transport.

1.2 Flatbed semi-trailer

Flatbed semi-trailers come in various types, each designed to meet specific transportation needs. The most common types include standard flatbeds, drop decks (also known as step decks), and extendable flatbeds. These different types of flatbed trailers provide a range of options to suit various cargo needs, whether it’s for long, tall, heavy, or delicate items.

• Standard flatbed semi-trailer (steel, aluminum, combo steel + aluminum, composite)

Skeleton/flatbed semi-trailers are versatile and widely used in the logistics industry. They consist of a flat, open deck with no walls or roof, facilitating easy loading and unloading of goods from any side. Standard flatbed semi-trailers are commonly used for transporting large and heavy items such as construction materials, heavy machinery, and vehicles.

• Extendable flatbed semi-trailer (steel)

Extendable flatbed trailers, or stretch flatbeds, are designed to transport long cargo that exceeds the length of a standard flatbed trailer. These trailers can extend from a standard length (usually 48 feet) up to about 80 feet or more, depending on the model. They are ideal for transporting substantial containers carrying loads like steel beams, pipes, and other long items.

• Drop deck semi-trailer (steel, aluminum, composite)

A drop deck or step deck semi-trailer has two deck levels: an upper deck near the tractor and a lower deck that drops after the wheels. This design allows for taller containers that exceed the height limit of a standard flatbed. These trailers are commonly used for transporting taller machinery, vehicles, and equipment that cannot be transported on a standard flatbed without exceeding height restrictions.

1.3 Lowboy semi-trailer

• Fixed gooseneck lowboy

This type of lowboy trailer has a fixed neck, making it more rigid but also limiting its versatility in loading options. It’s often used for transporting loads that do not require detaching the trailer bed and is suitable for those who frequently carry cargo on flatbeds. Recently, there are two main types of fixed-neck lowboys available in the market:
– Fixed gooseneck lowboy (FGN): The gooseneck is permanently attached to the trailer frame, making it lighter and generally more affordable than RGNs. It’s a reliable choice for loads that do not need height adjustments or detachment.

– Removable gooseneck lowboy (RGN): The gooseneck can be detached, allowing the front end to drop to the ground to create a ramp. This feature is beneficial for transporting heavy machinery or self-propelled equipment with low ground clearance, offering greater flexibility for various cargo.

– Fixed neck lowboy: Similar to the FGN in terms of attachment, the gooseneck is designed to connect directly to the deck without the curved “goose” shape, providing a straightforward, rigid structure.

In terms of additional features, fixed-neck lowboys can be divided into categories:

– Extendable lowboys: Designed with an extendable deck that can be lengthened to transport oversized cargo safely.

– Hydraulic lowboys: Equipped with hydraulic systems that raise and lower the deck, simplifying the loading and unloading process.

– Mechanical lowboys: These use mechanical components to either detach the gooseneck or adjust the deck length, often being more economical than hydraulic models.

Here are examples of specialized lowboy trailers based on these categories:

– Hydraulic detachable lowboy (flat floor, paver): This low-to-the-ground trailer features a flat deck and a detachable front gooseneck, making it easy to load and unload equipment like paving machines that require a stable surface. The hydraulics enable smooth, controlled raising and lowering of the trailer bed.

– Detachable double drop (mechanical/hydraulic neck): This model has a unique double-drop deck that dips down in two places, allowing for extra-low clearance. With a detachable front end, it can be adjusted using a mechanical or hydraulic system, providing a low-profile deck suitable for tall or awkwardly shaped equipment.

– Hydraulic tail trailer: This one has a back end that lowers to the ground like a ramp, making it easy to drive equipment onto the trailer.

1.4 Dry van Semi-Trailer

A dry van is a type of enclosed trailer widely used in freight transportation, specifically designed to protect cargo from external elements. Constructed with solid walls and a roof, dry vans are ideal for a range of goods that require a controlled environment without the need for temperature regulation. Dry vans come in various types, classified by length, construction, and features.

Dry vans are often available in lengths of 28, 45, 48, and 53 feet, with 53 feet being the most common for larger shipments.

Classification by construction type:

• Sheet and post: The most common type, featuring thin metal sheets attached to vertical posts for added stability and structure. These vans are generally lighter and more cost-effective, making them ideal for a range of standard applications.
• Plate/composite: Known for their enhanced strength and durability, these vans have solid composite panels forming the walls. While they offer a smoother interior for cargo, they are typically heavier and more expensive due to the sturdier build.

Classification by features:

• Standard: This is the basic enclosed box design with doors at the back, suitable for general cargo needs.
• Ventilated: Equipped with vents to allow airflow, these vans are essential for cargo types sensitive to temperature and moisture, such as fresh produce.
• Plate trailers/Composite dry van: These vans are specially designed for transporting heavy steel plates, often including specialized slots or racks to secure the cargo.
• Garment Trailers: Built with internal rails or racks, garment trailers are ideal for transporting clothing on hangers, preserving its shape and quality.

“Specific Vans” – Custom designs for unique needs:

• Livestock Vans: Featuring added ventilation, these vans cater to animal transport, ensuring adequate airflow for comfort and safety.
• Furniture Vans: Often equipped with additional padding and tie-down points, furniture vans are tailored for safely moving large, delicate items.
• Moving Vans: Typically outfitted with liftgates and wider doors, these vans facilitate the transport of household goods, making them suitable for residential moving.
• Specialized Vans: In addition to the above, many vans may be custom-modified to meet the demands of unique cargo types, each tailored to specific requirements.

1.5 Reefer semi-trailer

“Reefer” is a refrigerated trailer towed by a conventional semi-truck. These trailers are distinct from dry vans, which are only insulated and ventilated. A reefer often transports food, pharmaceuticals, or other perishable items.

Reefer semi-trailers are crucial to the food supply chain and serve as the principal means of delivering fruits, vegetables, frozen meals, meats, flowers, medical supplies, and more commodities. Reefers, constructed from aluminum or stainless steel, include insulated walls to provide temperature regulation, enabling the transportation of perishable commodities over extended distances.

1.6 Specialized semi-trailers

• Modular (Multi-Axle) semi-trailer

A modular (multi-axle) semi-trailer is a highly configurable trailer for transporting extremely heavy or large loads. These trailers are built with multiple axles that can be added or removed depending on the weight and size of the cargo. The modular design allows for better load distribution across several axles, minimizing the risk of damaging roads and infrastructure. They are commonly used in industries like construction and energy to move heavy machinery, transformers, or wind turbine components.

• Livestock semi-trailer

A livestock semi-trailer is specially designed to transport farm animals, such as cattle, pigs, or sheep. These trailers feature ventilation systems, non-slip flooring, and partitions to ensure the well-being of the animals during transit. They are typically built with multiple decks to maximize the number of animals that can be transported while maintaining comfort and safety. Livestock semi-trailers are essential for farmers and businesses involved in animal transport, providing a secure method to move animals over long distances.

• Tank semi-trailer (tanker)

A tank semi-trailer is a type of multi-purpose container used for transporting gasoline, diesel, and petroleum in liquid or gaseous form. These tank trailers are manufactured according to ISO standards, known as ISO tank containers, making them suitable for various types of transportation. Both hazardous and non-hazardous materials, such as liquids, gases, and powders, can be transported using tank semi-trailers.

• Dump semi-trailer

A dump semi-trailer is a trailer used to transport loose materials, such as gravel, sand, or demolition debris, that can be easily unloaded by “dumping” the cargo. These trailers are equipped with a hydraulic lift that tilts the trailer bed, allowing the load to slide out at a designated location. Dump trailers are commonly used in construction, mining, and agriculture.

• Car hauler semi-trailer

A car hauler semi-trailer is designed for transporting multiple vehicles. These trailers are fitted with racks and adjustable decks, allowing cars to be stacked and secured in multiple rows. Car haulers are used by dealerships, rental companies, and manufacturers to deliver new or used vehicles. Some models have both open and enclosed configurations to protect vehicles during transit.

• Low loader semi-trailer

A low loader semi-trailer (or lowboy) has a loading deck that is much lower than standard trailers, allowing it to transport heavy and tall machinery or equipment that would not fit under standard height restrictions on roads.

• Dolly Tandem semi-trailer

Dolly Tandem, also known as “dolly trailer” or “converter dolly,” is a type of trailer used to connect and pull different trailers in a long convoy, with a payload capacity of up to 44,000 lbs (equivalent to 20,000 kg). Dolly semi-trailers are often used in intermodal transportation systems, where a single truck can pull multiple trailers in succession.

2. Key specifications of semi-trailers

2.1 Dimensions of semi-trailers

Semi-trailers come in various dimensions based on their design and intended use. Common lengths for standard semi-trailers are:

• 53 feet: Common for freight transport.
• 48 feet: Often used for shipping containers.
• 45 feet: Suitable for specific cargo requirements.
• 40 feet: ISO standard size, suitable for international intermodal transportation.
• 20 feet: ISO standard size, suitable for intermodal transportation within the border.

The width is typically 102 inches (8.5 feet), and the height can vary depending on the trailer type (e.g., flatbed, refrigerated).

2.2 Payload capacity

The payload capacity of a semi-trailer varies depending on the trailer type and construction but generally ranges from 25,000 to 45,000 pounds. It’s crucial for operators to understand the maximum allowable weight, including cargo and trailer weight, to comply with federal regulations.

2.3 Tare weight

​​The tare weight of a semi-trailer refers to its weight when empty. This weight can vary significantly based on the trailer type and materials used in construction, typically ranging from 10,000 to 15,000 pounds. Understanding tare weight is essential for calculating the payload capacity accurately.

Impact of Federal Regulations on Actual Cargo Weight Federal regulations, which limit the total vehicle weight, directly impacts the permissible cargo weight. The maximum gross vehicle weight (GVW) allowed is generally 80,000 pounds for combination vehicles in the U.S., including tractors and trailers. Adhering to these regulations helps maintain road safety and infrastructure integrity.

Weight distribution and related regulations: Proper weight distribution across axles is essential for vehicle stability and safety. Federal regulations dictate specific axle weight limits:

• Single axle: Typically up to 20,000 pounds.
• Tandem axle: Typically up to 34,000 pounds.

2.4 Semi-trailer height

The height of semi-trailers can significantly influence their load and stability. Most semi-trailers have a standard height of around 13.5 to 14 feet, which is critical for ensuring clearance on highways and underpasses.

3. Tips for maintaining semi-trailers

Proper maintenance is essential for the durability and safe functioning of semi-trailers. Regular inspections and maintenance may avert malfunctions, prolong the trailer’s lifetime, and perhaps decrease long-term repair expenses.

Routine tire inspections: Tires must be examined for deterioration and appropriate inflation levels. Proper tire pressure enhances fuel economy and minimizes the likelihood of blowouts. Confirming that the tire treads have enough depth guarantees that the tires provide sufficient traction for safe navigation.

Examination of the brake system: Semi-trailers endure large loads. Consequently, regular brake inspections are essential for maintaining safe vehicle speed and stopping when required. Verify that the brake pads, drums, and air brake systems operate efficiently to avert suboptimal braking performance, brake malfunctions, and possible accidents.

Lubrication of mobile components: Consistently lubricating the trailer’s mobile components, including the landing gear, suspension elements, wheels, and axle systems, guarantees seamless functionality and mitigates excessive wear.
Evaluating lighting and electrical systems: Adequately operational lighting and electrical systems are crucial for safety. Consistently inspect for defective wiring or burnt-out lights to guarantee adherence to road safety regulations.

4. Factors for choosing suitable semi-trailers

Choosing the appropriate semi-trailer necessitates evaluating many aspects, including the trailer’s intended use, dimensions, and load capacity. Aligning these parameters with your individual needs guarantees operational efficiency and cost-effectiveness.

4.1 Purpose and application

The principal use of the semi-trailer is a crucial determinant in identifying the most appropriate kind. Flatbed trailers are optimal for delivering huge commodities, whilst reefers are designated for perishable things. Skeleton semi-trailers are designed for the transportation of intermodal containers, tanker trailers are intended for liquid freight, and car haulers are specialized for the conveyance of vehicles. Comprehending the intended use facilitates the refinement of your choices and guarantees the selection of a trailer that optimally accommodates your cargo requirements. Selecting the appropriate semi-trailer for the particular kind of freight is essential for regulatory compliance and the safety of the carried items.

4.2 Size and capacity

To ensure that the container chassis satisfies your operating requirements, it is essential to have a thorough understanding of its cargo capacity as well as its dimensions. Make sure that the payload capacity of the chassis you choose is equal to the weight of the containers and freight that it will be transporting. The act of overloading may result in several negative consequences, including breaches of traffic and transportation restrictions, damaged containers and chassis, and potential safety hazards. Additionally, the chassis needs to be suitable for the sizes of the containers that you want to carry, with the most typical sizes being 20 feet, 40 feet, and 45 feet containers. Check to see whether the chassis can support these dimensions without affecting the stable and secure performance of the vehicle.

5. Thaco Trailers – Vietnam’s leading semi-trailer manufacturer, meeting diverse transportation needs in the North American market

Thaco Trailers has continually established its presence with many export shipments to semi-trailer distributors in the North American market. To address varied transportation requirements, Thaco Trailers prioritizes research and development initiatives, introducing a wide array of products with unique configurations designed for the North American market.

Thaco Trailers currently offers an extensive selection of shipping container chassis, including intermodal chassis (slider, extendable, and standard), specialized semi-trailers, and OEM specialized semi-trailer components. These products deliver outstanding performance with superior load capacity, cost-effective operation, advanced designs, and reliability backed by cutting-edge manufacturing and adherence to international standards. With an optimized design, Thaco Trailers strikes a perfect balance between strength, stability, and versatility, catering to transportation demands from containers to specialized cargo.

Thaco Trailers’ products comply with local standards and fulfill the rigorous requirements of the North American market and international specifications, including ISO 9001:2015 and ISO 14001:2015 certifications, as well as adherence to traffic and safety regulations set by authorities such as DOT, AAR, ANSI, TOFC, F(C)MVSS, SAE, and TTMA.Thaco Trailers offers a diverse range of products with lightweight, high durability, flexible configuration design, optimizing load capacity, powerful operation, stability, and cost-effective operation. Explore Thaco Trailer’s extensive inventory of shipping container chassis available for purchase and choose the perfect option for your business now! For further information on our shipping container chassis, we invite you to visit our website or contact us directly for personalized advice on the appropriate container chassis for your needs.

Contact Information:

• Website: https://thacotrailers.com/
• Hotline: (+84) 933 805 707
• Email address: thacosv@thaco.com.vn