Devices to control access and transit were in existence well before the Christian Era. The word ‘barrier’ is derived from ‘bar’, meaning a physical obstruction, and can be traced back through French to its Latin roots. Today it is often used in connection with the controlled blocking of traffic lanes, so that barriers and vehicles are items of hardware that frequently work together.
The barriers at railroad crossings appeared with the introduction of signalmen/gatekeepers on railroads in the first half of the nineteenth century. At that time, grade crossings needed to be supervised to prevent trains colliding with horse riders, pedestrians and herds of livestock. Initially, simple pivoted booms were used for this purpose (the word ‘boom’ is Dutch for tree, a straight tree trunk serving as the barrier). Technical progress in the second half of the nineteenth century resulted in the barriers being coupled in pairs and operated remotely by cables. Later, mechanical drives came into use, which greatly reduced the effort required to operate the barriers. The German penchant for standardisation naturally came to the fore: in 1929 the first uniform design of barrier went into operation with the Reichsbahn, the national railroad operator at that time. Seven years later, this was adopted as the standard model. After the Second World War, these mechanical barriers were retrofitted with electric drives, further reducing the work involved for the signalman. Purely electric barrier drives which are easily controlled locally and remotely, have been installed since the 1950s.
Barrier manufacturers had a boom (in the other sense of the word) when business surged due to horsepower of the hoofed variety giving way to the horseless carriage. The success of the automobile led to the phenomenon of the parking lot, nowadays more likely to be described as ‘jam-packed’ than ‘free’, unless of course access is regulated by means of barriers. In the case of companies the security aspect must also be taken into account, since it is not desirable for unauthorised persons to have free movement in their vehicles – whether cars or trucks – on corporate property. Barriers, therefore, constitute a very common component of present-day perimeter security.