Flagpole safety in Belgium: wind, height and power lines

A flagpole is a tall, slender structure that catches a lot of wind. Most risks have to do with wind, working at height and cables in the ground or in the air. This guide sets out the points to consider, with the Belgian rules that go with them.

Wind and storms

The Belgian national annex to the Eurocode on wind actions, NBN EN 1991-1-4 ANB, uses a reference wind speed of 23 to 26 m/s: according to Odisee University of Applied Sciences, 26 m/s in Bruges and 23 m/s in Arlon, with a peak velocity pressure about 28 per cent higher in Bruges. The flag adds considerably to the wind load on the pole, and the larger the flag, the greater the force on the pole and the foundation.

Manufacturers design their poles for a given wind speed and flag size. A flag larger than specified loads the pole beyond what it was designed for. When a storm warning is issued, it is customary to take the flag in and, on telescopic poles, to retract the pole.

Lightning

A free-standing pole is often the highest point in the area. Metal poles conduct electricity. During thunderstorms it is customary to keep away from the pole and to hoist or lower the flag only after the storm has passed. For poles on large buildings, the building's lightning protection is often part of the design.

High-voltage lines and cables

KLIM-CICC warns that insufficient distance from overhead high-voltage lines and underground electricity cables can cause major damage and serious injury, and that accidents with pipelines for natural gas and other substances can have serious consequences. When a pole is installed, lowered or transported, the distance to overhead lines matters. For digging, reporting is mandatory via KLIP in Flanders and KLIM-CICC in Brussels and Wallonia, as described in the guide on flagpole installation. If a pipe or cable is hit, KLIM-CICC advises stopping work immediately, moving everyone to a safe distance and notifying the operator and, if necessary, the emergency services.

Working at height

Maintenance at the top of a pole, such as replacing the pulley or the finial, takes place at height. For employees, title 5 of book IV of the code on well-being at work applies, covering work equipment for temporary work at height. According to the FPS Employment, a ladder may only be used as a workstation for short-duration work with light loads, and movable ladders are secured before being climbed. For other work at height, the code lists scaffolding, aerial work platforms and other suitable work equipment.

A pole with a tilting base or in a ground sleeve can be lowered or taken out, so that the work can be done on the ground. That is one reason why tilting poles are popular with associations and municipalities.

Vandalism and theft

Circular VR 2015/37 points out that isolated poles are more exposed to vandalism and theft, and recommends taking in the flags on such poles in the evening on Flemish public buildings. An internal halyard with a lockable hatch makes it harder to steal the flag or cut the halyard.

Checking and maintaining

Circular VR 2015/37 recommends regularly checking the number of poles and their physical condition: where and how they are fixed, whether the hoisting mechanism works and whether the ropes are in order. More on this is in the guide on flagpole maintenance.