Telescopic Bollards: Smart Access Control for Modern Sites
Telescopic bollards — also known as retractable bollards — offer a clever engineering solution for sites that need to control vehicle access without the disruption of removing and storing a traditional removable bollard. Instead of being lifted out, a telescopic bollard retracts downward into an underground housing, becoming flush with the ground surface when not in use.
How Telescopic Bollards Work
A telescopic bollard system consists of an outer sleeve permanently installed in the ground and an inner post that slides upward to restrict access or downward to allow it. The mechanism for raising and lowering varies:
- Manual mechanical: A key retracts a spring-loaded locking pin, allowing the bollard to be pushed down manually
- Hydraulic manual: A pump mechanism builds hydraulic pressure to raise the bollard
- Gas strut: A compressed gas strut assists raising and lowering, reducing physical effort required
Where to Use Telescopic Bollards
- Pedestrian precincts and shared spaces: The gold standard for city centre access management — when down, the surface is completely unobstructed
- Private car parks and communal driveways: Cleaner aesthetics than removable bollards as there is no bollard to store or trip over
- Fire station and emergency vehicle access routes: Emergency services can be provided with keys or override codes
- School drop-off zones: Raising bollards during school run times prevents vehicles parking on school frontages
- Hotel and hospitality entrances: Maintains a clean, uncluttered appearance when vehicle access is permitted
Installation Requirements
Telescopic bollards require a deeper ground installation than standard bollards, as the full height of the post must be accommodated underground when retracted. Typical requirements: excavation depth 900mm to 1,200mm depending on bollard height; diameter of excavation 250-400mm; C25 concrete recommended; drainage essential to prevent the housing filling with water.
Maintenance Considerations
- Lubricate the sliding mechanism quarterly with waterproof grease
- Clear debris from the housing regularly, particularly leaf litter in autumn
- Inspect the locking mechanism annually
- Check that the drainage system is clear to prevent water ingress
Cost Comparison
Telescopic bollards are typically 30-60% more expensive than equivalent removable bollards due to the more complex mechanism. However, they offer significant operational advantages in high-use installations. The absence of a bollard to handle or store when access is needed makes them preferable for locations with frequent legitimate access requirements.