Types of barrier
Contents |
[edit] Introduction
A barrier is any object or mechanism that is designed to prevent people, animals, vehicles and so on from entering a restricted area, or to contain them within an area. Barriers can constitute permanent or temporary obstacles. If temporary, their status can be changed periodically to allow entry and exit.
Typical forms of barrier include:
[edit] Fences
All fences are barriers to entry (or exit), although they can also be used for delineation purposes. They typically combine strong, immovable materials of a height to ensure they cannot be climbed, or at least, form a deterrent from straying into or out of an area. Fences can also be very low and easily traversable, if their purpose is more signatory e.g by keeping people to a pathway or discouraging walking on a grassed area. Fences may also be electrified as a further deterrent to either people or animals.
[edit] Gates
Gates are barriers to entry and exit, but have the advantage of being opened temporarily to allow passage in and out. They can be incorporated as part of fences or as part of permanent structures.
[edit] Boom barriers
Boom barriers (also known as boom gates), can be conceived of as gates which instead of opening in the horizontal plane, operate by rising and falling. They are typically pivoted on one side and counter weighted to allow smooth, easy manual operation. They can also be motorised and are usually painted in conspicuous colours such as with alternating red and white bands. To further increase their visibility, a second arm can be suspended around 300-400mm below the main arm by metal straps which gradually revert to the vertical position as the boom is raised.
[edit] Traffic barriers
Traffic barriers separate vehicles from people or vehicles from other vehicles. The latter are seen on the central reservations of motorways and are sometimes referred to as ‘crash barriers’ as they are designed to prevent vehicles from crossing the central reservation into oncoming traffic. They are usually made of steel, are typically around 600-700mm high and have a corrugated profile for extra strength. They are designed to absorb the energy of a collision and in so doing deflect the vehicle into a parallel path to the barrier; this helps prevent vehicles breaking through into the other carriageway. Motorway crash barriers can also be made of reinforced concrete or steel wire cables.
[edit] Security (vehicle) barriers
In an age where some buildings require protection from terrorist attack, centres of government are often provided with large, heavy barriers placed at strategic points to prevent entry or ramming by cars and other vehicles. They are usually very large weights, often less than 1m high, and must be craned into position. Once in place, they are difficult to move, other than by crane. They are usually placed with gaps to allow pedestrians to walk through.
[edit] Others
Other forms of barrier may include:
- Topographical features such as mounds or ditches.
- Landscape features such as hedges or other planting.
- Bollards.
- Water features.
- Some forms of hostile architecture.
- Railings.
- Banisters.
- Guarding.
NB Urban Design Guidelines for Victoria, published by the State of Victoria (Australia) in 2016, states: ‘Barriers such as bollards and fences can define boundaries and protect people from traffic hazards and level changes. They also protect trees and shrubs from people and vehicles. A barrier may be made as bollards, screens, rails, fences, kerbs and walls. Barriers and fences can provide an opportunity for public art or to communicate local stories. They may also provide opportunities for seating.’
[edit] Related articles on Designing Buildings
- 2021 survey on public safety in crowded places.
- Access control.
- Access to construction sites.
- Approved document Q.
- CCTV.
- Collective restraint systems.
- Commercial security systems.
- Entry control.
- Fence.
- Hostile architecture.
- Palisade.
- Portcullis.
- Purchasing security gates and barriers.
- Ram raid.
- Scarp.
- Security and the built environment.
- Security glazing.
- Talus.
Featured articles and news
Building Safety Regulator reforms
New roles, new staff and a new fast track service pave the way for a single construction regulator.
Cooling centres and cool spaces
Managing extreme heat in cities by directing the public to places for heat stress relief and water sources.
Winter gardens: A brief history and warm variations
Extending the season with glass in different forms and terms.
Restoring Great Yarmouth's Winter Gardens
Transforming one of the least sustainable constructions imaginable.
Construction Skills Mission Board launch sector drive
Newly formed government and industry collaboration set strategy for recruiting an additional 100,000 construction workers a year.
New Architects Code comes into effect in September 2025
ARB Architects Code of Conduct and Practice available with ongoing consultation regarding guidance.
Welsh Skills Body (Medr) launches ambitious plan
The new skills body brings together funding and regulation of tertiary education and research for the devolved nation.
Paul Gandy FCIOB announced as next CIOB President
Former Tilbury Douglas CEO takes helm.
UK Infrastructure: A 10 Year Strategy. In brief with reactions
With the National Infrastructure and Service Transformation Authority (NISTA).
Ebenezer Howard: inventor of the garden city. Book review.
The Grenfell Tower fire, eight years on
A time to pause and reflect as Dubai tower block fire reported just before anniversary.
Airtightness Topic Guide BSRIA TG 27/2025
Explaining the basics of airtightness, what it is, why it's important, when it's required and how it's carried out.
Construction contract awards hit lowest point of 2025
Plummeting for second consecutive month, intensifying concerns for housing and infrastructure goals.
Understanding Mental Health in the Built Environment 2025
Examining the state of mental health in construction, shedding light on levels of stress, anxiety and depression.
The benefits of engaging with insulation manufacturers
When considering ground floor constructions.
Lighting Industry endorses Blueprint for Electrification
The Lighting Industry Association fully supports the ECA Blueprint as a timely, urgent call to action.