The term "overhead wire" refers to wires that are suspended above the ground, usually used for the transmission of electricity or telecommunications signals. The spelling of this term in IPA phonetic transcription is /ˈoʊvərˌhɛd waɪər/. The initial syllable is pronounced with a long "o" sound, followed by the unstressed "v" and "er" syllables. The pronunciation of the final two syllables is "h-eh-d" and "w-ai-r". This spelling accurately represents the pronunciation of each sound in the word "overhead wire".
An overhead wire refers to a cable, typically made of copper or aluminum, which is suspended above the ground level and used to supply electricity to various transportation systems, such as trains, trams, trolleybuses, and some types of electric automobiles. Also known as catenary wires or overhead lines, they are fixed to supports such as poles or pylons, forming a network along the route of the vehicle or train.
The overhead wire system works through a process called catenary, where the wire is shaped in an upside-down U or parabolic curve to counterbalance the weight and tension. The wire carries high-voltage electricity, which is delivered to the transportation system through a pantograph or trolley pole, a device mounted on the vehicle that makes contact with the wire and channels the power to the equipment or motor.
Overhead wires are essential for providing a continuous power supply to electric transportation systems, eliminating the need for on-board energy storage. They offer advantages such as a relatively cheap and reliable power source, scalability for different distances, and the ability to deliver significant current for high-power vehicles. Proper installation and maintenance of overhead wires are crucial to ensure efficient electrical transmission and safe operations.
Overall, overhead wires have revolutionized the transportation sector, providing a cleaner and more sustainable option compared to vehicles powered by fossil fuels. They play a fundamental role in modern electric transport infrastructure, enabling the widespread adoption of electric powered transportation across the globe.
The word "overhead wire" is a compound word consisting of "overhead" and "wire".
- "Overhead" is derived from Middle English "overhed", which comes from the combination of "over" (meaning above or beyond) and "hed" (meaning head). It refers to something that is situated or positioned above or over one's head.
- "Wire" comes from Old English "wīr", which is similar to the Old High German "wir". It refers to a thin, flexible thread or strand made of metal such as copper or steel.
Therefore, the term "overhead wire" refers to a wire or cable that is positioned or suspended above someone's head, typically used for various purposes like electricity transmission or as a support for transportation systems such as railways or tramways.