In what cases and for what a low -grade trailer is used? What are low -grade trailers and semi -trailers? What are the main characteristics of such a technique? All this will be discussed in more detail.
First of all, it should be understood that the low -gramoid trailer technique is of two types: trailers and semi -trailers. The main purpose of such equipment: transportation of road and construction equipment, building structures. Depending on the design and the number of axes, the carrying capacity of the low -graders starts from the modest 20 and reaches a size of 70 or more tons.
It is not difficult to visually determine the carrying capacity of the low -grab semi -trailer. On average, each axis is designed for a load of 9-11 tons, on a saddle-compound device, as a rule, a load of not more than 15-20 tons is transferred. The weight of the structure itself varies around 10-12 tons. Thus, three-axle low-grains can rarely take a load weighing more than 35-40 tons, four-axle models-43-48 tons, five-axle models-up to 60 tons.
Of course, there are models with a lightweight design, when, due to its own smaller weight, the transportation of a heavier cargo is allowed, and models with increased permissible load on the axis, but the general principles are the same-the distribution of the load between the saddle and axes.
By the way, everything above is true not only in relation to low -graphic technique, but also to any other types of semi -trailers. But what is significantly distinguished by low -grade platforms from others, it is a low loading height. There are models in which the height of the platform is only 600 mm. And this gives undeniable advantages when transporting bulky equipment. After all, the lower the platform, the higher equipment can be transported along the roads on which tunnels, power lines, etc. D. Of course, not any low -grain has such a low loading height. Mostly there are models with a platform of 800-950 mm high.
The low height of the platform of such a semi -trailer is achieved in two ways. Moreover, one of them cannot be called more popular, since low-grade semi-trailers (trawls) of two species are distributed almost the same.
The first option. Manufacturers use in the design of the axis of the axis with wheels of small diameter, due to which the low height (800-900 mm) of the cargo platform is achieved. In this case, it, as in the standard semi -trailer, is located above the wheel.
The second option. Manufacturers use the axis with a standard size in the design of the trawl of the wheels, however, the frame of the semi -trailer is blown up when the cargo platform is between the hussak and the axis. Such trawls are often lower, however, have a lower length of the cargo platform.
A significant difference between such low -graders from each other can be called that in the first case, loading of equipment onto the platform is usually carried out using folding appellations installed in the rear of the trawl, while in the second case trawls C, the so -called, frontal loading are more often common.
Comparing low-gradual semi-trailers with a frame above the wheels and with a “broken frame”, such models can be given as an example, for example, Kassbohrer LB4E in the first case, and Altinordu Alt-LW-4 in the second.
With the development of the economy as a whole and the construction sector in particular, the semi -trailers of heavy trucks began to be increasingly popular among carriers and large production companies, which, due to their activities, were forced to carry both construction equipment and finished products.