How Telescopic Bollards Work
All telescopic bollards share the same basic architecture: a cylindrical steel bollard body (the post) that slides up through a ground-level housing (the foundation cassette). The mechanism that raises and lowers the post distinguishes automated from manual systems. Foundation cassettes are typically installed in pits 500–1200mm deep, making installation in existing hard-standing a significant civil engineering operation. Foundation design must account for ground conditions, underground utilities, road construction depth, and maintenance access requirements.
Manual Telescopic Bollards
Manual bollards use a key-operated gas-assisted mechanism. The operator inserts a key, turns it, and the bollard lifts smoothly under gas strut assistance. Operated entirely without electricity or hydraulics.
Advantages
- No power required — no electrical supply needed at the installation point
- Typically 30–50% less expensive than automated equivalents
- Lower maintenance — no hydraulics, motors, or control systems
- Fail-safe mechanical reliability — no electronics to fail
Disadvantages
- Requires a person physically present to operate
- Not suitable for high-frequency access
- Key management challenging in large organisations
- Cannot integrate with ANPR, access control systems, or intercoms
Best applications: Low-frequency access locations — pedestrian areas with occasional delivery access, heritage spaces, private residential where the occupant is normally present.
Automated Telescopic Bollards
Hydraulic Systems
Use a pump and cylinder system. High force capability suitable for heavy-duty security and certified HVM applications. Fast operating times (1–3 seconds for rapid-rise security bollards). Robust in high-usage environments. Higher maintenance requirement — hydraulic fluid levels, seals, and pump servicing at 6-monthly intervals.
Electromechanical Systems
Electric motor driving a mechanical actuator (lead screw or rack-and-pinion). Clean installation — no hydraulic fluid risk. Suitable for medium-security and standard access control applications. Typical operating time 4–8 seconds. Lower maintenance than hydraulic. Increasingly the dominant technology for mid-range applications.
Control and Integration Options
| Control Method | Application |
|---|---|
| Key switch | Simple on-site control; limited user management |
| Key fob / remote control | Single or multi-user; convenient for regular users |
| Access card / fob reader | Managed access with audit trail; multiple users |
| ANPR camera | Fully automated whitelist/blacklist vehicle management |
| Intercom / video intercom | Manned or remote security control |
| Traffic signal interface | Town centre access tied to pedestrianisation times |
Safety Requirements for Automated Bollards
- Safety edges on the rising bollard top that stop/reverse movement if resistance is detected
- Inductive loops detecting vehicles directly over the bollard to prevent premature rise
- Warning signals: amber flashing light and audible warning before rise cycle begins
- Emergency stop accessible for immediate halt of operation
Security Performance Ratings
- IWA 14-1:2013: International standard for vehicle security barriers — specifies vehicle type, speed, and maximum penetration depth
- PAS 68:2013: British standard covering hostile vehicle mitigation; being superseded by IWA 14 but still referenced
- CPNI guidance: Centre for the Protection of National Infrastructure Catalogue of Security Equipment
Maintenance Requirements
| System Type | Service Interval | Key Tasks |
|---|---|---|
| Manual (gas strut) | Annual | Strut pressure check, lock mechanism lubrication |
| Electromechanical | 6-monthly to annual | Motor, actuator, safety sensors, control system |
| Hydraulic | 6-monthly | Fluid level/quality, pump, seals, control system |
Conclusion
Manual systems suit low-frequency, cost-sensitive applications. Automated hydraulic systems suit high-security, high-frequency or speed-critical applications. Electromechanical offers the middle ground for most standard access control installations. Browse our telescopic bollard range for manual and automated options.