Automatic barriers

A barrier goes where you need to close a driveway rather than an opening: a residential courtyard, a shop car park, the entrance to a company site. It will not stop anyone on foot - its job is to keep other people's cars out.

The key parameter is not boom length but duty cycle: the share of time the motor can run without pausing to cool. 50% is enough for a courtyard with a few dozen entries a day; 80-100% is needed where cars arrive in a stream - an office block, a paid car park, a factory gate.

The second parameter is speed. Standard models raise the boom in about 5 seconds, which is fine for a courtyard. High-speed versions do it in 1.5-3 seconds: where hundreds of cars pass daily, a few seconds add up to a queue.

Boom length follows the driveway width: 3-4 metres for an ordinary courtyard, 5-6 for a wide entrance, up to 9 metres for industrial gates. Booms can have rubber edging, lighting, a skirt underneath or a resting post for the longest spans.

Everything runs on 230 V - no separate power line is needed. Brushless motors cost more but have no brushes to replace and tolerate continuous duty, which is why they go on 100% intensity sites.

Control is by remote, button, key switch, keypad or card reader. Residential buildings usually take a remote per flat; businesses prefer cards or plate recognition, since a remote is easy to hand on to someone else.