Overhead Power Supply
Since 1999 Metro de Madrid uses a new patented system for its installations: a solid track hung from the ceiling of the tunnels, instead of the usual copper or aluminium wire. This type of catenary (or overhead line) is rigid, making it more robust and less prone to failures. Installations outside of tunnels are rare, as they require many more support structures compared to traditional wire based overhead lines, making them more expensive to install.
This system of rigid overhead power supply is also used elsewhere.
Read more about this topic: Madrid Metro
Famous quotes containing the words overhead, power and/or supply:
“During a walk or in a book or in the middle of an embrace, suddenly I awake to a stark amazement at everything. The bare fact of existence paralyzes me... To be alive is so incredible that all I can do is to lie still and merely breathe—like an infant on its back in a cot. It is impossible to be interested in anything in particular while overhead the sun shines or underneath my feet grows a single blade of grass.”
—W.N.P. Barbellion (1889–1919)
“Perfect happiness I believe was never intended by the deity to be the lot of any one of his creatures in this world; but that he has very much put in our power the nearness of our approaches to it, is what I steadfastly believe.”
—Thomas Jefferson (1743–1826)
“Municipal laws are a supply to the wisdom of each individual; and, at the same time, by restraining the natural liberty of men, make private interest submit to the interest of the public.”
—David Hume (1711–1776)