Flagpole safety
Published Written by Flagpole Guides
This page is an English translation of the Portuguese original. Where the two versions differ, the Portuguese text is the original.
A flagpole is a tall, slender structure exposed to the wind all year round. The main risks are wind, nearby power lines, buried cables when digging the foundation and work at height during assembly and maintenance. This guide brings together what Portuguese bodies say about those risks.
Wind
The wind load on a flagpole grows with its height and with the size of the flag. According to a Portuguese supplier, a 200 × 300 cm flag has four times the area of a 100 × 150 cm one, and a larger flag significantly increases the area exposed to the wind. The manufacturer states the largest flag and the wind speed the pole is designed for.
According to the National Annex to the standard for calculating wind actions (NP EN 1991-1-4), the country is divided into two zones. Zone B covers coastal areas in a 5 km strip exposed to sea wind, the archipelagos of the Azores and Madeira and areas above 600 metres in altitude. In those zones the wind values used in design are higher.
IPMA warnings
The Portuguese Institute for Sea and Atmosphere (IPMA) issues weather warnings for strong wind at yellow, orange and red levels, by district and region. It is common to take the flag down when there is a strong-wind warning: the fabric wears less, and the load on the pole and foundation drops. According to the supplier cited, the smaller size in the range is the more common one at sites with frequent gusts.
Overhead power lines
E-REDES, which runs the distribution network on the mainland, recommends the following distances in work with cranes and loads between the conductors of a line and any part of the crane or load:
| Line voltage | Distance |
|---|---|
| Up to 60 kV | 3 metres |
| Above 60 kV | 5 metres |
According to E-REDES, any conductor of a power line is always considered live unless a written statement from a company representative confirms that it is de-energised and earthed. A pole raised near a line, or falling onto it, can enter the danger zone. It is therefore common to place the pole further from the line than its own length.
Buried cables
When digging the foundation, the risk lies in buried cables. E-REDES asks to be contacted before drilling or digging, to find out whether there are cables nearby. According to E-REDES, they are approached with hand tools, without a pickaxe, and work within 1.5 metres of the cables is supervised by a qualified person. The subject is covered in the guide to flagpole installation.
Work at height
Replacing the halyard or pulley on a fixed pole is work at height. A tilting base allows the pole to be lowered and maintained from the ground. On rooftop poles, assembly and maintenance take place on the roof, with fall protection equipment. Maintenance is covered in the guide to flagpole maintenance.
Children and public spaces
At schools, parks and public spaces, an external halyard can be pulled or cut. A pole with an internal halyard and a lockable box reduces that risk, as well as flag theft. The difference is described in the guide to flagpole mechanics.
Warning signs
Cracks in the base or foundation, loose bolts, corrosion at the joints, a leaning pole or unusual noises in the wind are signs of wear or damage to the structure. The most common problems are described in the guide to flagpole repair.
Frequently asked questions
What distance is there between a flagpole and a power line?
E-REDES recommends, in work with cranes and loads, a distance of 3 metres from the conductors of lines up to 60 kV and 5 metres from higher-voltage lines. A pole that falls or is raised close to a line can enter that zone.
Is it common to take the flag down in strong wind?
Yes, although no law requires it. According to a Portuguese supplier, a larger flag greatly increases the area exposed to the wind, and it is common to take the flag down when IPMA issues warnings of strong wind, to protect the pole and the fabric.
Where is the wind action greatest in Portugal?
According to the National Annex to the standard for calculating wind actions, zone B, with higher values, covers a 5 km coastal strip exposed to sea wind, the archipelagos of the Azores and Madeira and areas above 600 metres in altitude.
Sources
This guide is based on the following sources, most of them in Portuguese:
- Trabalhos próximos da rede elétrica: linhas aéreas – E-REDES
- Trabalhos próximos da rede elétrica: cabos subterrâneos – E-REDES
- Guia de utilização dos avisos meteorológicos – IPMA
- Critérios gerais de projeto (ação do vento segundo a NP EN 1991-1-4) – Agência Portuguesa do Ambiente (consulta pública)
- Como escolher o tamanho da bandeira para o mastro – Mundo das Bandeiras
Related guides
- Flagpole installationPutting up a flagpole in Portugal: what the RJUE says, the municipal regulations, listed buildings, condominiums, the foundation and buried cables.
- Flagpole maintenanceMaintenance of the flagpole and the flag: halyard, pulley, foundation, cleaning and sea air, and the good condition required by Decreto-Lei n.º 150/87.
- Flagpole materialsFlagpole materials in Portugal: aluminium, fibreglass, steel and wood, their properties, resistance to sea air and the effect on price.
- Flagpole repairCommon flagpole faults and repairs: broken halyard, stuck pulley, wrapped flag, corrosion, loose base, leaning pole and the legal guarantee.
- Flag sizesFlag sizes in Portugal: the official proportions of 1911, the usual sizes, the relationship with the height of the pole and the rules of the Azores and the GNR.