A bollard is a short vertical poll. The first bollards were used to moor large ships to the dock and are still used today. A typical bollard is made of cast iron or steel and is shaped like a mushroom; the enlarged top is intended to prevent the lanyard from slipping. Today the word bollard also describes a wide variety of structures used on roads, around buildings, and in landscaping.
The most common type of bollard is fixed. The simplest is an unsightly steel post that is approximately 914 to 1219 mm above the level. The specially made bollards not only include simple posts, but also a wide variety of decorative designs. They are square or rectangular in cross-section, but most are cylindrical, sometimes with a domed, angled, or flat top. They are available in a variety of durable powder coatings, painted, and metallic finishes.
Removable bollard lights are used when the need to limit access or occasional changes in direct traffic changes. Both retractable and flip-up models are used where selective access is often required and are designed so that the bollard can be easily folded to floor level and quickly raised again. The units can be operated manually or automated with hydraulic movements. Movable bollards are large, heavy objects, often stone or concrete, that do not rely on a structural anchor to stay in place. like a forklift.
The most popular uses for bollards are traffic control, direction and security. The first function is achieved by the visual presence of the bollards and, to a certain extent, by the impact resistance.