SHANDONG CAESAR INTENATIONAL TRADE CO.LTD.

As a vital pillar of modern logistics systems, box semi trailer have long been scrutinized for their fuel consumption and load capacity. Aerodynamic drag, as one of the key factors affecting box van trailer fuel consumption, has consistently posed a challenge for semi trailer manufacturers and logistics companies. Significant differences exist between European and Chinese dry trailers in terms of tractor-trailer coupling methods, resulting in considerable variations in aerodynamic performance. This paper delves into a comprehensive analysis of the characteristics of these coupling methods, exploring effective approaches to reduce aerodynamic drag in Chinese van semi trailers. The aim is to provide reference recommendations for advancing dry van semi trailers towards greater energy efficiency, environmental sustainability, and increased load capacity.

This is a DAF box truck trailer from Germany, with a distance not exceeding twenty centimeters between the tractor and semi-trailer. The spacing between them adopts a wider upper and narrower lower configuration, ensuring that the cabin does not come into contact with the tractor when navigating uneven road conditions.

For convenient access to the truck, this part of the air deflector is movable.

Once opened, the internal articulated mechanism becomes visible, facilitating inspection and maintenance at the rear of the truck.

This is a Dongfeng Tianlong semi-trailer from China, where the distance between the tractor and trailer should be no less than one meter.

Clear differences in design between European and domestic van trailers are evident from the above two images. While ensuring safety and maneuverability, European van trailer strive to minimize the distance between the tractor and trailer, forming a tight assembly. This design allows airflow to smoothly pass over the tractor and dry trailer through the air deflector, effectively reducing aerodynamic drag. Conversely, the significant distance between the tractor and dry freight trailer of domestic trucks leads to a considerable portion of airflow redirecting towards the front of the trailer after passing through the deflector hood, creating additional aerodynamic drag and directly impacting driving efficiency. One of the reasons for this difference is that European tractor units typically adopt a 4X2 configuration with a wheelbase of 3.8 meters, whereas domestic tractor units are often 6X4 models with a wheelbase of 3.3 meters plus a trailer coupling distance of 1.35 meters. Hence, the distance between the front and rear axles of domestic tractor units is longer than that of European counterparts.

How can Chinese dry van trailers be optimized to reduce aerodynamic drag akin to European box van trailers? Different from other dry truck manufacturers in China, the saddle can be moved forward, which will reduce the load of the middle and rear axle, but increase the load of the front axle, which is not conducive to safety. Caesar Trailer, one of the best dry van trailer brands, uses a solution that moves the trailer towing pin back. This solution involves moving the trailer towing pin backward during custom dry van trailer customization and employing high-quality steel plate springs to counteract the pressure exerted by the mid and rear section steel plate springs. Its advantages lie in shortening the distance between the tractor and trailer units, reducing aerodynamic drag, shortening the overall vehicle length, and improving maneuverability. For existing dry box trailers, a section can be extended in the front of the truck bed to reduce wind resistance and improve cargo carrying capacity.

It is worth noting that both the rear-sliding trailer towing pin and extending the front portion of the trailer will increase the outward swing angle of the trailer's front end during turns, such as an increased outward swing of the right front corner of the trailer during a left turn. Special attention must be paid during actual operations, as this places higher demands on the driver's experience and skills.

Additionally, the distance between tractor and trailer should be determined based on specific road conditions. Caesar Trailer can flexibly adjust according to customer needs and road conditions to ensure optimal performance and safety.

Advantages of "Short Intercept" Design:

The widespread adoption of the "short intercept" design, where the distance between the tractor and trailer is minimized, typically controlled within 20cm. This design concept stems from our research on dry van semi trailers worldwide, amalgamating their strengths.

Improved maneuverability: The shortened wheelbase enables semi van trailers to maneuver and turn more flexibly, especially in urban logistics and complex road conditions.

Enhanced stability: The shorter wheelbase makes the dry van trailer turn more stable at high speeds, effectively reducing the risk of rollover and improving driving safety.

Reduced wear: Short wheelbase designs minimize tire and suspension wear, extending the box semi trailer's lifespan and lowering maintenance costs.

Optimizing Vehicle Exterior:

Side skirts for semi-trailers. Most European dry van trailers are equipped with side skirts between the two axles.

Extending even to the area between the tractor and trailer and the rear of the trailer's third axle, maximizing aerodynamic drag reduction.

This IVECO truck is a standard European curtain sider trailer, specifically designed for bulk cargo transport.

This trailer is used for bulk cargo transport in China.

Caesar Trailer typically feature smooth and flat exterior surfaces without corrugated panel designs, or with minimal transverse corrugations. This design not only enhances the structural strength of the van trailer but also effectively reduces aerodynamic drag. This is because each corrugation increases aerodynamic drag. 

In contrast, corrugated panel trailers designed for container transport do not need to consider reducing aerodynamic drag since the trailer owners are not engaged in transportation operations. In comparison, other Chinese dry van manufacturers adopt corrugated panel designs due to their lower costs, but this design also leads to considerable aerodynamic drag during operation.

In addition, the common domestic fence semi-trailer and flatbed trailer will also increase wind resistance when the outside is covered with tarpaulins and ropes.

Therefore, Caesar Trailer employ a unique rope tightener design when customers need to use tarpaulins and ropes. In order to better transport goods and minimize wind resistance.