Tubular steel mast
In overhead line construction , a tubular steel mast is understood to be an overhead line mast made from hollow steel profiles . A tubular steel mast is usually delivered to the installation site in just a few individual parts, assembled there and then erected with a crane.
In Germany and Austria tubular steel masts are mainly used for medium-voltage lines, but also for high-voltage lines with one or two circuits for operating voltages of up to 110 kV. In France, tubular steel masts are often used for 380 kV lines, and in the USA for 500 kV lines.
Also cable car supports for cable cars are often made in the form of tubular steel mast, as well Oberleitungsmasten for trams and trolleybuses .
Rope-braced tubular steel masts are used in Germany and some other countries as self-radiating transmission masts or as carriers of transmission antennas for radio services in the UHF / VHF range. They have the advantage that the cables are protected from the weather, but have the disadvantage that they tend to vibrate due to wind. Vibration dampers, such as those on the masts of the Saterland marine radio station, provide a remedy . Cross beams from the mast body to the ropes can also have a vibration-damping effect ( 30 107 KM ).
history
Until 1965 Thomasstahl was used in Germany to manufacture the masts. The high nitrogen content caused by the manufacturing process led to material fatigue, so that masts were broken from 1986 onwards. In the 2000s, these masts were therefore replaced.