Heavy cargo transportation is an indispensable guarantee in the construction of national key projects. With the continuous improvement of national manufacturing capacity, the demand for heavy cargo transportation shows an increasing trend year by year.

Large cargo transportation refers to the transportation and distribution of large equipment. Because the goods carried are huge, heavy and indivisible, and even exceed the specified limits of highway alignment and bridge and culvert carrying capacity, they can not be completed by ordinary transportation vehicles. The transportation difficulty is also clear, which requires that the transportation speed must be slow, Driving skills and driving experience must be very high.

Generally, the size and load standard of large transport vehicles are different according to the different goods transported, which can be divided into the following types:

1. Super width standard for heavy cargo transport vehicles

The width of heavy goods transported on class I roads is limited to: greater than or equal to 3.5m and less than 4.5m;

The width of heavy goods transported on class II roads is limited to: greater than or equal to 4.5m and less than 5.5m;

The width of large goods transported on class III roads is limited to: greater than or equal to 5.5m and less than 6m;

The width of heavy goods transported on class IV roads is limited to more than 6m.

2. Super length standard for heavy cargo transport vehicles

The length of large goods transported on class I roads is limited to: greater than or equal to 14 meters and less than 20 meters;

The length of large goods transported on class II roads is limited to: greater than or equal to 20 meters and less than 30 meters;

The length of large goods transported on class III roads is limited to: greater than or equal to 30m and less than 40m;

The length of large goods transported on class IV roads is limited to more than 40m.

3. Super high standard of large cargo transport vehicle

The height limit of class I road large cargo transportation is: greater than or equal to 3m and less than 3.8m;

The height limit of heavy goods transported on class II roads is: greater than or equal to 3.8m and less than 4.4m;

The height limit of heavy goods transported on class III roads is: greater than or equal to 4.4m and less than 5m;

The height of heavy goods transported on class IV roads is limited to more than 5m.

4. Load standard of heavy cargo transport vehicle

The weight limit of class I road heavy cargo transportation is: greater than or equal to 20t and less than 100t;

The weight of heavy goods transported on class II roads is limited to: greater than or equal to 100t and less than 200t;

The weight of heavy goods transported on class III roads is limited to: greater than or equal to 200t and less than 300t;

The weight of heavy goods transported on class IV roads is limited to more than 300t.

In some special cases, the weight of goods to be transported by large cargo transportation vehicles can reach 500t or even 1000t, so that one vehicle cannot complete the transportation task alone, and two or more tractors are often required to cooperate with the transportation. Therefore, there are mainly the following modes of large cargo transportation:

1. Single vehicle traction

This is also the most common mode of transportation. It is not much different from ordinary cargo transportation. It is generally transported by large cargo transportation tractor, semi-trailer or hydraulic semi-trailer. It is suitable for large cargo transportation with a total weight of less than 250t.

2. Single vehicle traction plus push

It is also called top cart transportation. As the name suggests, it is to use a tractor or semi-trailer to transport in the front, and then add a tractor at the back. Use the top push rod tripod to connect its front with the rear of the vehicle carrying goods, so that the rear tractor can push the trailer.

This mode of transportation can be semi-trailer or full trailer. It is generally used for large cargo transportation below 350t. When the traction of a single vehicle is insufficient, it can be used with the rear tractor. However, in order to prevent the rear tractor tire from slipping, appropriate counterweight will be added on the rear tractor to improve the adhesion of the rear tire and give full play to the power of the rear vehicle.

3. Double vehicle traction plus push

In principle, it is similar to single vehicle traction plus push, but the number of tractors is different. The two front tractors, generally hydraulic full trailers, are connected to the front beam of the trailer through hinges, and the two rear tractors are also connected to the rear beam of the trailer through hinges. The four tractors work at the same time to complete the transportation task. Tractors can be towed side by side or in series. Since the tractor uses a full trailer, the weight of the goods can be evenly distributed to each tire.

This mode of transportation is applicable to the large cargo transportation with a total weight of less than 500t. It has high requirements on the road and terrain. The rear tractor also needs counterweight to ensure sufficient power.

4. Multi vehicle traction plus push

For heavier goods, such as large goods with a total weight of more than 500t, the transportation mode of multi vehicle traction and push can be adopted to ensure sufficient power. The connection method is the same as that of double vehicle traction and push.

It is worth noting that when the number of tractors or pushers exceeds one, it is necessary to report to relevant departments in advance, explore the transportation route in advance, and complete the transportation within the specified time and route under the unified organization, road opening, flow restriction and supervision of relevant departments. In some cases, it may be necessary to build roads and bridges by yourself. In addition, in the process of transportation, the cooperation between multiple tractors is very important, and its gear, speed and other parameters must be consistent. When going up and down a slope, it is necessary to accurately regulate the front and rear vehicles to ensure the front and rear power balance.

The commonly used models of heavy cargo transport vehicles are mainly flat cars, ladder cars, groove cars, etc. from the perspective of axle classification, they can be divided into three lines and three axles, three lines and six axles, four lines and eight axles, five lines and ten axles, and so on. Due to the special type of goods transported, the requirements for various configuration parameters of the vehicle are higher, such as the load-bearing performance of the vehicle.

When it comes to vehicle load-bearing, we have to mention the support axle. Generally, the axles used on semi-trailer are support axles. Although they do not have driving and steering functions, they are directly related to the strength of vehicle load-bearing capacity. Darong heavy industry group is one of the earliest enterprises in China to start mass production of one-piece axle. With more than 20 years of R & D and production experience, Darong heavy industry group has directly built the axle body and axle head from one piece of steel in the casting process, which has changed the traditional "three-piece" welding mode, avoided welding deformation and improved the load resistance of the axle body.

At the same time, the key parts of the connection between the shaft head and the bearing are specially thickened in design, and the medium frequency induction strengthening treatment is added to improve the strength and toughness of the shaft head and ensure the stability under high-speed operation. Over the years since entering the market, Darong axle has established good cooperative relations with many customers with reliable quality and affordable price.