In ancient times, the transportation of large pieces on land was carried out by using simple tools, relying on a large number of human or animal power for dragging, or by covering the road surface with water and ice in winter. After the emergence of modern electric power and machinery industry, people used motors, winches (or other traction machinery), pulley blocks, wire ropes, rollers, jacks and sleepers to transport large pieces by rolling and dragging. Until today, this method is still used for highway transportation of large cargoes, especially in waterway transportation or railway transportation loading and unloading places where the transportation distance is not long and large lifting equipment is lacking.
With the development of modern large industry, the volume and weight of equipment used in chemical, petroleum, metallurgy and electric power industries are increasing day by day. One piece of equipment often weighs hundreds to hundreds of tons, and its width and height can reach five or six meters, and its length can reach tens of meters, or even more. Some of these large pieces can be transported by water or railway for long-distance transportation. In areas where there is no water or railway, or because waterway transportation is limited by channel depth and bridge clearance, and railway transportation is limited by tunnel, bridge, station clearance, etc., highway transportation with fewer restrictions and easy to overcome difficulties has to be used; In addition, almost all the destinations for large cargo transportation by water and railway, the distance from the wharf or railway station, will also be completed by road transportation. Under the circumstances of this objective need, super heavy truck trains are gradually emerging. The modern highway heavy cargo transportation using super heavy truck and train started in the early 1960s in the industrial developed countries. In 1967, China first carried out this kind of highway heavy cargo transportation in Shanghai; It has developed rapidly since the mid-1970s. In the past decade, we have successively transported extra heavy equipment with an overall weight of more than 500 tons, extra long equipment with a length of more than 70 meters, and extra wide and extra high equipment with a width of more than 9 meters, a height of more than 12 meters, and a length of nearly 20 meters. It is safe and fast to use the technical performance of super heavy truck trains to transport large equipment of modern industry.
In the early 1980s, a new process called "module" was developed in some countries, that is, the factory was divided into several units for construction. After completion, each unit (i.e. module) will be transported to the construction site for assembly. This kind of module weighs from several hundred tons to several thousand tons, and its length, width and height can reach tens of meters respectively. Super heavy truck trains can also be used to transport such large pieces. In addition, it can also be carried by a kind of flat car group called self-propelled.
For the transportation of large pieces, because the gross weight of vehicles and goods, overall dimensions, etc. exceed the prescribed limit of the highway, it is necessary to report to the relevant traffic management department and take necessary engineering technology and transportation organization measures. Before transportation, it is necessary to check the weight, size, center of gravity and fulcrum position of the large pieces transported, equip corresponding vehicles, determine the bearing capacity of the road section and bridge and culvert, the geometric dimensions of the road width, curve radius, longitudinal slope and crown, the clearance clearance of the overpass, tunnel and other structures, the overhead wires and obstacles on both sides of the road, and formulate the transportation plan. The road sections that are not suitable for super heavy truck trains to pass through shall be reconstructed, bridges and culverts shall be reinforced, obstacles shall be removed, or temporary measures shall be taken, such as detour driving, building temporary bridges, building temporary roads, etc. For large pieces with special weight and size, driving simulation test shall be carried out first when necessary to check whether the road can pass. During the actual transportation, the traffic management department shall announce to the masses in advance and temporarily block the traffic by sections. The road shall be opened by the command vehicle, overhead stringing vehicle, etc. to eliminate all kinds of interference and overhead obstacles. When passing through large cities, transportation can also be arranged at night according to the situation to reduce the impact on normal urban traffic. (See color picture)