Tower Crane Intruder Alarm

Large construction sites in London have recently seen an increased risk of members of the public seeking unauthorised access to site after hours. As well as the security risk, this presents a major health and safety risk for the public and anyone working at that time, such as site security staff. Located in busy Soho, Ilona Rose House recognised this risk and have trialled a tower crane intruder system to deter trespassers and reduce the health and safety risk.

The intruder alarm has two battery powered PIR sensors with built-in sounders. One of the sensors is situated at the base of the tower crane and will be triggered if the door is opened. The second sensor is on the anti-climb frame below the hatch. This sensor has a sim card with three mobile numbers saved. If it detects an intruder climbing the tower crane after hours, it will sound an alarm and calls and texts the three numbers with a pre-recorded message notifying relevant staff that the alarm has been set off.

The PIR sensors are very sensitive so it took some fine-tuning to ensure they do not send false alarms. So far, the trial has been successful with only false alarms being sent during the day, and no alarms after hours.

This is a unique, yet simple and cost-effective way of minimising the safety and security risk of having members of the public accessing our site at night. Despite standard security measures on construction sites (such as solid hoarding, security teams, CCTV and lighting), more is needed to reduce the risk of trespassers accessing site. This is an effective system to reduce the safety risk of trespassers accessing the site.