China is a big country of coal production and consumption. The road coal transportation market is a very important market for heavy truck manufacturers and trailer manufacturers. There are many types of road transportation vehicles, but so far there is no tractor that can meet the needs of coal transportation.

Coal transportation vehicles refer to special vans equipped with coal loading carriages, etc., which have the functions of preventing throwing and easy for loading and unloading. They are used to transport coal. What is meant by a vehicle that truly meets the needs of coal transportation? The person in charge of an enterprise who has been deeply involved in the coal transportation market for a long time summed it up as "loadable" + "unloadable".

"Loadable" means that the vehicle can achieve the maximum allowable loading capacity specified by the standard without losing load. "Unloadable" means that it can unload automatically, efficiently, environmentally, and safely.

I. Analysis of regulations

1. GB-1589 "Outer Dimensions, Axle Loads and Mass Limits of Automobiles, Trailers and Automobiles and Trains"

According to the limit requirements of GB1589 on axle load, total mass and outer corridor size, the "3+3 semi-trailer truck" has the highest loading capacity, and its maximum allowable total mass limit is 49t. Therefore, the 3+3 semi-trailer truck is the main vehicle type in China's road transportation market.

2. QC/T980 "Coal Transport Vehicle"

The definition and technical requirements of coal transportation vehicles are stipulated, but in terms of vehicle model structure, only transportation vehicles in long-distance sections are considered (only 8×4 chassis or 3-axle semi-trailers should be adopted, and the height of the fence shall be ≤1.5 m, and does not clearly require whether the vehicle must have a dump function).

In addition, as a recommended standard for the industry, this standard has a legal status lower than GB-1589, so it has not been adopted by the competent authority of the announcement. As a result, manufacturers are unable to develop and produce corresponding products in accordance with QC/T980, not to mention household operations. The entire industrial chain has brought contradictions and helplessness.

II. Problems with compliant models

1. The flatbed truck that complies with the regulations "cannot be installed":

GB1589 stipulates that the height of the cargo box of the flat truck is less than or equal to 600m, but the total mass after being filled with coal is far below the total mass limit stipulated by laws and regulations, thus there is a "loss load", resulting in low transportation efficiency and low load quality utilization factor.

For example, a 6-axle semi-trailer tractor has a total mass limit of 49t according to regulations and a curb mass of about 16t for a conventional train, so the actual load of the train trailer should be 33t. However, according to the requirements of GB1589, the size of its cargo compartment should not exceed 13000×2400×600mm, so its cargo compartment volume should not exceed 13×2.4×0.6=18.72m³.

The 18.72m³ volume can hold up to 18-20t of coal (the density of coal is only 0.8-1.1t/m), which is far below the total mass limit specified in GB1589, resulting in a deficit of 13-15t (the deficit rate is as high as 40 %-45%), the transportation efficiency is too low and users cannot operate normally.

2. Warehouse trailer that comply with laws and regulations "cannot be unloaded":

GB1589 stipulates that the warehouse truck has a fence with a height of 1800-2000mm, which is suitable for transporting non-bulk goods, but the coal transporter can load coal to a total mass of more than 40t by adding a "guard" around the fence, and then cover it with canvas. Can basically realize "environmental protection transportation".

However, although the fence trailer has solved the problem of "unloading", it has caused the embarrassment of the "cannot be unloaded". According to GB1589, the fence trailer cannot have a self-unloading function and can only be unloaded manually, which has low production efficiency and unsafe conditions and factor. At the same time, there are still some defects in the storage of coal when transporting coal.

III. Current status of non-compliant models

1. Containerized flatbed dump semi-trailer

The conversion of a flat dump semi-trailer into a containerized dump coal truck is very practical, but it is suspected of "illegal modification" because of the fixed connection of the trailer body (box) to the vehicle flat panel.

2. Warehouse type dump semi-trailer

Warehouse type dump semi-trailers modified based on fence vehicles, etc., are very practical, but they are suspected of "illegal modification" because they are equipped with a dump system.

3. Dump semi-trailer with heightened fence

Based on a compliant dump truck (height of the fence ≤600mm), heightening the fence (or adding a warehouse fence) to a height of 1.5-2m is suspected of "illegal modification".

Although these three types of models are "non-compliant", over the years, industry authorities and localities have different understandings of the relevant provisions of GB1589, resulting in differences in local law enforcement, thus obtaining a lot of room for survival, especially a large number of used in the domestic medium and short-distance road coal transportation market.

IV. How to deal with the compliant transportation

Countless examples have proved that the safest, most efficient and most environmentally friendly transportation of many goods can only be achieved by using specialized transportation vehicles.

The “trailer fence height must not exceed 600mm” in the “other requirements” of GB1589 does not fully consider the transportation needs of various goods and imposes excessive restrictions on vehicles, which has led to the abnormal development of similar vehicles across the country.

The "small capacity" dump semi-trailer produced by 600mm can only be used to transport goods with a large proportion, but it is difficult to transport coal and other bulk cargo. The "large capacity dump semi-trailer" with a wide range of uses can be "loaded and unloaded", but it can not get normal development. Therefore, we should remove the obstacles restricting the healthy development of mainstream vehicles in China's coal transport market from the source as soon as possible.

▎Summary

For the 3-axle coal transportation semi-trailer, in order to fully realize the lightweight design of the whole vehicle, when the cargo box fence adopts 1.5m height, the semi-trailer can be "loaded" without losing load, and in order to facilitate loading and airtight transportation , The top of the "cargo box" is allowed to set up a movable ceiling, and the lower part of the "cargo box" is also allowed to be set up with a spray dust pressure device.

Through standard revision work, a professional coal transportation vehicle capable of fast loading and unloading, environmentally-friendly unloading, safe unloading, and environmentally-friendly transportation can be realized at the same time, that is, “loadable, unloadable”, “pulling coal without coal, unloading without dust”.