What is a Skeletal Trailer – Detail Design Specification

The skeletal trailer, also called skeleton trailer or skeletal semi trailer, is used for transporting ISO tanks, ISO containers, and refrigerated containers. Both flatbed trailers and skeletal trailers can transport containers.


The Skeletal trailer mainly comprises the main, cross, and front and rear beams. The height of the beam is usually 450mm to 500mm.  The main beam is made into a groove shape of high-quality steel. The front and rear beams are rectangular in shape.

An integral long beam is provided at the location of the twist lock to improve the bearing capacity of the lock.

two axles 20ft intermodal container chassis trailer for sale

20ft container chassis trailer

Difference between the skeletal trailer and flatbed trailer 

The flatbed trailer has a frame and patterned steel plate floor, while the skeletal trailer does not have these. The entire frame is assembled and welded at a dedicated position. The flatbed trailer is with a reasonable structure and beautiful appearance.

Container twist locks are set on the frame, which can load two 20ft containers or one 40ft container. The four tightening devices at the front and rear are fixed structures, and the middle tightening device is a concealable structure.

3 Axle 40 ft Skeleton Semi Trailer Prepared for Philippine

40ft container chassis trailer

Loading containers

The intermediate twist lock should be lowered below the beam when loading containers as required. The landing gear plays an important role. It can bear the front load of the trailer when the tractor is disconnected from the trailer.

There are two types of supporting devices: single-acting and linkage-acting, which are mainly composed of supporting discs, screw drive mechanisms, speed reducers, and operating handles.


There are two types of suspension: mechanical suspension and air suspension. Air suspension is mainly used in places with poor road conditions, which is relatively expensive.

Base fender

Anti-shake, anti-corrosion, anti-bump.

If you still have questions about the skeleton trailer, please email manager@pandamech.com. Our engineers will reply you as soon as possible.

Container skeletal semi trailer design

The high-quality axles we use are from professional manufacturers.  The axles have a bigger loading capacity and are not easy to deform. Moreover, they can be equipped with ABS of famous brands, which can shorten the braking distance, prevent side slip, tail flicking, etc, caused by emergency braking, and improve safety.

Skeletal trailer humanized design.

  1. The limit device is equipped to twist the lock to make transportation safer;
  2. The twist lock handle has a beautiful appearance and is easy to operate;
  3. The front twist lock operation handle is placed inside the frame to prevent the handle from damaging;
  4. A two-position, three-way valve is added to the braking system to improve parking safety.


Main Beam“I” Section 500mm height Q345/T700 material
Twist-Lock4/8 set ISO Standard
SuspensionMechanical / Air
Axle2/3 axles, BPW/FUWA brand
Rim8/12 pieces 9.0-22.5
Tire8/12 pieces 12R22.5 Bridgestone/Triangle/Linglong etc
Brake ValveWABCO
Kingpin2″(50mm)/3.5″(90mm) JOST Bolting Type


1. The traction pin installation plate

Considering the different road conditions, flexibility and stability are both necessary. Panda Mech skeletal trailers reserve two kingpin installation positions. For extra-long containers, in slippery road conditions, the front one is more flexible; in terrible road conditions, the behind one is more stable. It is more adaptable.

2. The strengthened beam

The main beam is the main body of the semi-trailer. In the skeletal trailer, the main beam bears heavy loading and absorbs the shock. Panda Mech skeletal trailer main beam adopts the patented technology of composite reinforced beams, and front 8 and rear 5, which is load-bearing, anti-vibration, and anti-jump box.

3. Butterfly-shaped stress relief brace

Butterfly-shaped stress relief brace: more stable, providing a place for the stress to go. The skeletal trailer mainly load containers, which are quite heavy.  In addition to the stable frame structure, the stress relief area is also needed. The butterfly-shaped stress relief brace design of the Panda Mech skeletal trailer satisfies these two demands perfectly.

4. It is firm and pretty. Anti-friction rubber strips are added to the essential parts to avoid being worn or rubbing hard.

5. Bottom supported mudguard

Bottom-supported mudguard: anti-shake, anti-corrosion, anti-bump. Unlike the standard way of strengthening the top of the mudguard, the bottom supported mudguard of the Panda Mech skeletal trailer prevents the damage caused by the container bumps to the mudguard, making the vehicles look better.

6. Curved surface and wrapped angle design

This design reduces rigidity and makes the trailer fit for the container. Compared with the rigid angle design, this design is more flexible. It looks like the container will not touch the vehicle, and indeed it does reduce the collision with the container. This design is not to pursue aesthetics but to show that Panda Mech skeletal trailer was designed with the concept of “lower and lighter.”

7. Customized high-strength steel

The skeletal trailers made of customized high-strength steel are of high quality and stable performance. Vehicle accessories are all from well-known brands in the industry. We adopt the perfect design, control the quality strictly, make the product the best possible, and make its service life reach the highest standard in the industry. Our advanced technology, excellent quality, and after-sales service have obtained good evaluation in the special vehicle industry and our customers.

8. Stainless steel anti-wear and maintenance-free suspension, the anti-collision structure of the rear part.

The stainless steel anti-wear and maintenance-free suspension adapt to more complex road conditions, which have been well verified on the Panda Mech G series and T series.

In the rear part, we make the most muscular anti-collision structure, according to the actual needs of customers, reducing the damage caused by an inertial collision.

9. The locking beam uses high-strength materials

The high-strength steel, exquisite design of the ends, and the high standard cast steel lock increase the safety and reliability of the only part connected to the container during driving.

10. Exquisite production process

Professional and skilled welders perform well, making the welding seam is even and smooth, ensuring no spatter and welding slag. Shot blasting increases product strength and beauty. Any of Panda Mech’s products is not only a sturdy special vehicle but also artwork.

11. Protective cover for connecting device

A protective cover is added to the electrical and air circuit connection device to prevent short circuits caused by wetness and rainwater intrusion, prevent damage from dust and other falling objects, and increase the safety of sockets and connectors.

12. Aluminum alloy gas cylinder

Large-capacity, corrosion-resistant, non-impurity generated aluminum alloy gas cylinder reduces the safety problems caused by poor air ventilation during driving.

13. The diagonal bracing

The sturdy and reliable diagonal bracing reduces the hidden danger of deformation caused by traction during disassembly.

14. The insurance devices

A real-time air pressure detection device is adopted, which can show the air pressure all the time. An automatic tire inflation device is equipped, to inflate the tires in time in advance. Flame retardant tires containing zinc borate reduces spontaneous combustion at high temperatures. These bring safety, convenience, and comfort in actual operation and guarantee the driving safety and the service life of tires.