The word "Trolley wire" is spelled with the IPA phonetic transcription of [ˈtrɑli waɪr]. The first syllable is pronounced with an open-mid back rounded vowel 'ɑ', followed by a voiceless alveolar lateral fricative 'l' and a schwa 'i' in the second. The last syllable has a diphthong 'aɪ' followed by an alveolar approximant 'r'. The spelling of the word is relatively straightforward in English with its common rules, despite the presence of the phoneme 'ɑ' which can have multiple spellings depending on the context.
Trolley wire refers to an electrical conductor that supplies power to an electrically propelled vehicle, typically an electric powered tram or trolleybus, through an overhead power system. This wire is an essential component for the operation and electrification of the vehicle, allowing the transfer of electrical energy from the power source to the vehicle's motor.
Usually made from copper or aluminum, trolley wire is installed on a series of support structures, known as catenary poles or gantries, which are positioned above the tracks or roadways that the vehicle runs along. These structures provide the necessary mechanical support for the trolley wire and maintain it at a suitable height for the vehicle's pantograph or trolley pole to collect electricity.
The trolley wire is energized with a direct current (DC) electrical signal, typically supplied from a power station or substation. This direct current is then transmitted to the vehicle, where it is used to power the electric motor, propelling the tram or trolleybus forward. The trolley wire is designed to carry and distribute electrical power efficiently while withstanding environmental factors such as weather conditions and mechanical stresses caused by the pantograph or trolley pole.
Regular maintenance and inspections are necessary to ensure the integrity and safety of the trolley wire system. Over time, the wire may experience wear and tear, requiring repairs or replacements to maintain optimal electrical performance. Overall, trolley wire plays a crucial role in facilitating the operation of electrically powered vehicles, providing a reliable and efficient power supply mechanism for reliable and environmentally friendly transportation systems.
The etymology of the word "trolley wire" comes from the combination of two separate terms: "trolley" and "wire".
The term "trolley" originated from the early 19th century, derived from the word "troll", meaning "to roll" or "to wander". Originally, it referred to the wheeled cart or carriage used for transport or hauling goods. Over time, "trolley" came to specifically refer to the streetcar or tramcar, which was powered by electricity in the late 19th century.
The term "wire" refers to a thin, flexible metal strand typically made of copper or aluminum. In the context of "trolley wire", it specifically refers to the overhead wire used to provide electric power to the streetcar or tramcar.