Flagpole mechanics: external and internal halyards

The mechanics of a flagpole are simple: a rope, the halyard, runs through a pulley at the top and raises and lowers the flag. There are, however, differences in how the halyard runs and is protected. Decreto-Lei n.º 150/87 also says something about the mechanics: for half-mast, the flag first goes to the top and only then comes down to half-mast.

External halyard

With an external halyard, the rope runs along the outside of the pole. The flag is attached to the halyard with snap hooks, and the halyard is tied off to a cleat at the bottom. It is the simplest solution and the most common at houses.

Internal halyard

With an internal halyard, the rope and a counterweight run inside the tube. The halyard comes out through an opening with a lockable box at the bottom. It is a frequent solution at schools, businesses and public spaces.

Pulley and top

The pulley at the top is the part that works hardest. If it is stuck or worn, the halyard runs with difficulty or jumps off the pulley. On a pole with a tilting base, the pulley can be replaced with the pole lying down. The most common problems are described in the guide to flagpole repair.

Rotating arm

A rotating arm at the top, with a bearing, turns with the wind and keeps the flag spread out. It stops the flag wrapping around the pole, which happens in light, shifting winds. Some poles have a rotating ring instead of a halyard.

Raising and lowering

The decree only describes the half-mast procedure, but the mechanics are the same in every case. The flag is attached to the halyard by the snap hooks on the hoist, with the green next to the pole, and the halyard carries it up to the pulley, at the top, where it stays while the halyard is tied off to the cleat or fixed in the box. When the halyard is untied, the flag comes down.

At half-mast, the flag first goes to the top and then comes down to halfway, under article 7 of Decreto-Lei n.º 150/87. When taken down, it goes back to the top before descending. The subject is covered in the guide to half-mast.

Poles without a halyard

Telescopic poles and many façade poles have no halyard: the flag always stays at the top or is slid onto the pole by a sleeve. On such poles the flag cannot be set at half-mast. The types of flagpoles are described in the guide to types of flagpoles, and the parts in the guide to flagpole accessories.