Background and History of Crash Bars
– Crash bars were originally designed to prevent crowd crushing in emergencies.
– They are now commonly used as the primary door opening mechanism in commercial buildings.
– Modern fire standards often require the installation of crash bars in commercial buildings.
– Some crash bars are fitted with alarms for emergency use.
– Crash bars are preferred over knobs or lever handles for their speed and ease of use.
– The Victoria Hall disaster in 1883 led to the invention of the panic bolt by Robert Alexander Briggs.
– The Iroquois Theatre fire in 1903 and the Collinwood school fire in 1908 in the United States highlighted the need for better fire safety measures.
– The Glen Cinema disaster in 1929 in Scotland resulted in the death of 71 children due to padlocked exit doors.
– These incidents prompted the implementation of building codes requiring minimum safety standards.
– Crash bars became a common feature in public buildings to ensure quick and safe evacuation during emergencies.
Justification for the Use of Crash Bars
– Poor planning, design, control, and mismanagement are often responsible for crowd crush situations.
– Building codes require fire and emergency exits in public buildings.
– Crash bars are proven to save lives during mass evacuations caused by fires or explosions.
– They allow for quick passage through security doors without causing logjams at the exits.
– Crash bars are typically required in assembly areas, spaces with a large number of occupants, and hazardous areas.
Latching Mechanisms of Crash Bars
– Crash bars offer various latching configurations, such as vertical rods and center posts.
– Vertical rods allow both doors to be opened without obstruction and use a pullman latch mechanism.
– Some doors feature concealed vertical rods and latches within the door.
– Additional latching points may be added for security purposes.
– Center posts are an alternative to vertical rods and have fewer moving parts.
Unlocking and Latch Hold of Crash Bars
– Dogging is a feature that allows panic bars to be retracted with a key during business hours.
– Dogging is different from simple unlocking, which requires releasing the latches.
– Crash bars can be unlocked electronically, with a cylinder lock, or a hex key.
– Dogging should be avoided in high wind areas to prevent the door from blowing open.
– Electric strike crash bars use a touch sensor and electromagnetic lock, commonly used on secondary doors.
Panic Bar Styles and Differences between Europe and North America
– Cross bar style exit doors are used in Turkey.
– European Union standard EN 1125 governs panic bars operated by a horizontal bar.
– EN 1125 requires panic bars to conform to specific quality benchmarks.
– EN 1125 is one of two standards governing exit devices in the EU, the other being EN 179.
– EN 179 devices are used in locations where people are familiar with emergency exits.
– The first panic bar was made by Von Duprin in 1908.
– Building exit requirements in the US are controlled by model codes.
– Regulations can vary by location and may be supplemented with local amendments.
– Factors considered when mandating exit devices include the number of occupants, nearby exits, and proximity to hazards.
– Panic bars are frequently used in US commercial buildings even where not required by code.
– In Europe, panic bars are mostly cross bar style, while North America uses touch bars.
– Panic bars in Europe are generally used in code-required applications.
– In North America, panic bars are commonly used for ease of use and convenience.
– Automatic doors are preferred by the public, but can be costly to install and maintain.
– Some panic bars are designed to resist microbial growth with antimicrobial surfaces.Sources: https://en.wikipedia.org/wiki/Crash_bar
