Boom barrier
A barrier or a barrier, in Austria a barrier, in Switzerland a barrier is a structural device for blocking a path, consisting of a movable bar to one or two columns.
Typically, the rod is pivotably mounted, the axis of rotation, and usually opposed to a gate level. The small dimension of a barrier then allows it to fold to open up, which saves floor space. A classic barrier is a two-armed lever with a counterweight in order to minimize the force required for opening and closing.
First widespread usage barriers at border crossings, especially during the particularism. For ingestion of customs and other charges barriers can be built relatively easily. Toll booths and parking garages are common use cases in the present.
In the course of industrialization barriers were also a means of transport safety, as they were introduced at level crossings. Since the mass motorization forest roads are often blocked by barriers. Only there are simple models without electric motor still common.
A modern barrier arises not from a tree, but made of steel and are increasingly made of light metals and plastics. The lighter materials enable along with modern drive technology compact barriers that can be opened by an electric motor without being further dimensioned as a two-armed lever.
Red and white striped barriers are at least in Germany and traffic signs, marking road surfaces, whose sail prohibited. At border crossings barriers are consistently in the national colors. From barriers without contrast colors is in poor visibility of major accidents.
At level crossings sometimes half barriers are installed to keep half of the road width as escape route, so that no one is imprisoned between automatically closing gates. Originally railroad crossings have been moved out of bounds guards. Railroad crossings were formerly often equipped with additional curtains as sneak-. There are also barriers with applied shear grids as a fall protection. In particular, in the parking management also Knickarmschranken be installed now.