How Do Automatic Bollards Work?

21st February 2024

Automatic bollards, also known as automated or power-assisted bollards, are increasingly popular security solutions for commercial premises, car parks, and private properties across the UK. But how exactly does the technology behind these retractable barriers work? This guide provides an in-depth look at the key components and functionality of automatic bollard systems.

What Are Automatic Bollards?

Automatic bollards provide the convenience of retractable security barriers combined with electric power operation. They can be lowered flush into the ground to allow authorised vehicle access, then raised again as an obstruction using hydraulic or pneumatic power.

Controlled by built-in logic controllers, automatic bollard systems sense approaching vehicles and initiate the lowering sequence when access is permitted. Once the vehicle has passed, the bollards instantly rise again to prevent unauthorised entry.

Automatic bollards offer much greater ease of use compared to manually operated retractable or removable bollards. They also react faster in allowing and restricting access when integrated with access control systems.

Key Components of an Automatic Bollard System

Fully automated bollards rely on an interconnected system of mechanical, hydraulic and electronic components to function:

  • Bollard Casing and Housing – The visible bollard sleeve is made from sturdy steel or concrete material. This encases and protects the housing chamber underneath containing the bollard’s raising/lowering apparatus.
  • Hydraulic Power Unit – A hydraulic pump and reservoir provides the pressurised fluid to power the bollard’s extension and retraction. This is located out of sight in a separate underground service pit.
  • Cylinders and Pistons – Hydraulic cylinders containing pistons are fixed to the base of the bollard housing. As fluid enters the cylinder chambers, this forces the pistons and bollard sleeve upwards until fully extended. Reverse direction retracts the bollards.
  • Control Box & Logic Controller – An above-ground control box houses the logic controller responsible for operating the hydraulic system. This processes signals from access control devices and sends commands to raise or lower bollards accordingly.
  • Access Control Systems – These include RFID card/code readers, push-buttons, video intercoms, number plate recognition cameras, or smartphone apps. Access control devices send an activation signal to the logic controller when authorised.
  • Backup Battery System – A backup battery prevents bollards losing power and failing to raise during electricity outages. This ensures continuous security.

How Do Automatic Bollards Raise and Lower?

When someone approaches the entrance fitted with automatic bollards, here is the typical sequence of events:

  1. An authorised user presents credentials (e.g. access card) to the entrance’s access control reader.
  2. The credential is verified, and a signal is sent from the access control system to the bollard control box.
  3. The logic controller processes this signal and actuates solenoid valves to allow hydraulic fluid into the bollard cylinders beneath the ground.
  4. Pressurised fluid entering the cylinders forces the hydraulic pistons and attached bollard sleeves to retract downwards, flushing them level with the roadway.
  5. With the bollards fully lowered, the control system keeps them in the down position to allow the approved vehicle to safely pass across.
  6. Once the vehicle reaches a certain point, horizontal safety loops buried under the roadway send a signal back to the controller.
  7. The logic controller reverses the hydraulic flow, pushing fluid back into the cylinders under pressure.
  8. This hydraulic force extends the pistons and bollard sleeves upwards until they lock fully upright. The bollards are now raised again as barriers preventing unauthorised access.

For extra security, horizontal safety loops can also trigger bollards to pop up automatically if a vehicle is detected stopping or reversing once partially lowered. This prevents vehicles tailgating behind authorised cars from bypassing the entrance barriers.

Benefits of Installing Automatic Bollards

Some of the major advantages automatic bollard systems offer over manual alternatives include:

  • Enhanced convenience – Vehicles can effortlessly self-trigger the lowering sequence instead of needing manual bollard retraction
  • Rapid reaction times – Bollards lower and raise again more swiftly, reducing waiting times
  • Integration with access control – Bollards automatically respond to credentials scanned at the entrance for smooth access
  • Increased security – Quicker bollard activation reduces opportunities for unauthorised tailgating
  • Reduced risk of damage – Automated operation prevents human error and mishandling
  • Lower long-term costs – Automated systems have minimal maintenance needs compared to manual options

Choosing a Professional Installer

Having your automatic bollards expertly installed is critical for both security and longevity. Accredited bollard specialists will:

  • Survey your site and advise the optimal bollard placement
  • Handle all necessary groundwork, excavation and foundations
  • Install safety edge protection to prevent vehicle impact damage
  • Integrate your access control system with the bollard mechanisms
  • Fully test and commission the automated bollards once in place

Professional bollard contractors will also be able to service and maintain your automatic bollards over their lifespan. This keeps them functioning reliably for years while avoiding costly damages.

So for specialist advice and high quality automatic bollard installation across the UK, choose an experienced bollard system provider.