Three Aspects Contribute to Good Trailer Design :Stability, Trailer Strength, Versatility

Jul 28, 2015
When we mention good trailer design, there are generally three aspects taking into consideration: stability, strength, versatility. 
trailer stability

Stability of Truck Trailer

There are many factors that can affect towing stability of semi trailers. The performance of load distribution, trailer length, trailer brakes, dynamic loads, center of gravity all have a influence to  stability, but not one is absolute. 
  • Load distribution

load distribution plays a crucial role in the stability, and it is the easiest to change by only changing the load distribution on the front or rear deck of trailer. However the trailer load should be distributed reasonably, it’s very dangerous putting a lot more weight on one or the other side. More weight on the hitch, more stable, but commonly we put 15% of the total weight, which is a suitable number for loading. Load distribution is nothing but a question how loading weight should be put in a trailer. Putting more weight on the rear of tow vehicle can make the front vehicle rise, which tremendously affects stability and full of risks. It’s significant to use a reasonable distributing hitch, ensuring the control, driveability, and stability. 
  • Trailer length 

It has been found that longer trailers is more accurate for towing, which can achieve the perfect separation between the rear wheel and the front wheel. Otherwise, a long tongue can achieve such effect. When the distance between rear wheel and hitch is shorter, the trailer is more stable so that it can’t be influenced greatly by the rugged road compared with a long distance between the rear wheel and hitch.
trailer brake
  • Trailer brakes 

Trailer brakes to the tow vehicle needs to be discussed more. Trailer brakes should be suitable for the load and the intrinsic size. If the trailer is loaded, it is necessary to connect the brake, while empty, disconnect the brakes. which can avoid skid when the trailer is towed empty in this way.
  • Dynamic loads 

Dynamic loads have a profound impact on stability. For example, if a large heavy objects which can move freely carried on the trailer, it will obviously shift from side to side or front to back with motion of the trailer. The moving object will have an effect to the trailer on the contrary. Whereas the dynamic load is small compared with the weight of trailer, the effect may not be so apparent. While the moving load is a large, the effect can be quite salient. 
  • Center of gravity  

Center of gravity is another important aspect, the lower the center of the gravity, the more stable the trailer is. If the center of gravity is too high, the truck is more easily to tip over.  

Truck Trailer strength

Trailer Strength play a crucial role in the stability. Particularly with utility trailers, strength is of great significance for frequent overload or load unevenly. Trailers must be strong enough because it requires to carry all kinds of materials whenever it is needed. The factors that can affect trailer strength will be discussed below. 
load capacity

Load Capacity

The maximum load of the trailer will determine much about the strength of the trailer. The trailer’s strength is stipulated by its rated load capacity, a larger capacity trailer must be of heavier construction than a small capacity. For instance, a trailer of 5000 pounds must be heavier than a trailer designed for 1000pounds. The load capacity of trailer is related to the intended capacity.

Basic Trailer Layout

There is also a good assessment to evaluate the strength, basic trailer layout, it not only affect the stability in operation, but also determine the appearance of trailers. Three factors related to basic trailer layout. 
long tongue Vs short tongue
Length of the tongue.It is essential that the tongue should be long enough for a turning radius and reversing. Short tongue can affect driveability and stability, especially when backing up. A longer tongue is also beneficial for the axle separation, making the trailer more stable. 
Axle location. For stability, axle is installed behind the load center. Supposing that the axle is placed on the front of the center bed, this will affect the function of versatility. The position can be adjusted if needed, but for most instances, it is behind the center of the bed. 
Strong rear member. The bumper in the back of the trailer should be strong, by which the truck can realize the function of loading. So it is larger (stronger) than the other cross members. if it is damaged, there is a strong need to load the weight of overload.


Many parts of a trailer can contribute to strength or weakness, or be suggests of weakness or disadvantages in the design. Here are a few factors to note.
Ball receiver and hitch should be of appropriate size for the trailer capacity. The capacity of ball receiver and hitch must be in accordance with the giving rated load capacity .The ball receiver should be made for a ball of adequate size.  
The size of the axle should be in consistence with load capacity of the trailer. In generally capacity of the trailer is the function of the axle. The capacity of multi-axle is not the total sum of the axle rating because of the uneven load. During the actual operation, axle loading depends mainly on the mounting configuration.

different tires
Axle springs should in conformity with the trailer. A good design is usually equipped with a longer spring, it is useful for the distribution of load. Wheels must meet or exceed trailer load capacity. 

Choosing appropriate wheel is vital. Tire problems have troubled numerous trailer owners, it is necessity that tire ratings must match trailer capacity, and load rating must be appropriate. Often automotive tires are offered with a wider range of options.

Versatility of Truck Trailer

Versatility is a vague term, difficult to define. With regard to a utility trailer, the necessary options that make the trailer versatile much more depends on the intended use. Choosing the right trailer is very important, notice the following factors. 

Suspension Type

Suspension Type is a crucial factors to the versatility. leaf spring is so common and there are many options for choosing, single axle leaf springs, multiple axle leaf springs, slipper style leaf springs, torsion axles and so on. Slipper style leaf is relatively popular, and often used on multiple axles, possessing the features of stability and favorable load distribution.


Hitch is used to pull load, connected with a kind of special trailers, such as bumper type hitch, goose neck or 5th wheel. Load-distribution hitches is a very popular choice for making the trailer more stable with respect to the load. Dampers can also achieve this effect.
trailer chain

Safety chains           

Safety chains  is necessary on most circumstances, used for linking the towing vehicle and the trailer. Trailer chains should be of appropriate size, usually depending on the towing vehicles. Many light duty trucks use 5/16-inch thick chains, while medium-duty trucks employ half-inch chains. The chains should be secured in case of serious accidents.


Anyang Deli Special Vehicle Co., LTD.

  Add : No.2 Building, Huaqiang New Times, Xiange Avenue intersection with the Pingyuan Road, Development District, Anyang, Henan, P.R.C.

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