Editing Overhead line (section)

== Types of wires ==
{{Expand section|with=more details about other types of catenary wire in other countries.|talk=Catenary wire in other countries|small=no|date=June 2024}}
In the [[Soviet Union]] the following types of wires/cables were used.<ref>Исаев, И. П.; Фрайфельд, А. В.; "Беседы об электрической железной дороге" (Discussions about the electric railway) Москва, "Транспорт", 1989. pp, 186-7</ref> For the contact wire, cold drawn solid copper was used to ensure good [[Electrical conductivity|conductivity]]. The wire is not round but has grooves at the sides to allow the hangers to attach to it. Sizes were (in cross-sectional area) 85, 100, or 150&nbsp;mm<sup>2</sup>. To make the wire stronger, 0.04% tin might be added. The wire must resist the heat generated by arcing and thus such wires should never be spliced by thermal means.

The messenger (or catenary) wire needs to be both strong and have good conductivity. They used multi-strand wires (or cables) with 19 strands in each cable (or wire). Copper, aluminum, and/or steel were used for the strands. All 19 strands could be made of the same metal or a mix of metals based on the required properties. For example, steel wires were used for strength, while aluminium or copper wires were used for conductivity.<ref>See previous reference and Ботц Ю. В., Чекулаев, В. Е., Контактная сеть. Москва "Транспорт" 1976 p. 54</ref> Another type looked like it had all copper wires but inside each wire was a steel core for strength. The steel strands were galvanized but for better corrosion protection they could be coated with an anti-corrosion substance.

In [[Slovenia]], where 3&nbsp;kV system is in use, standard sizes for contact wire are 100 and 150&nbsp;mm<sup>2</sup>. The catenary wire is made of copper or copper alloys of 70, 120 or 150&nbsp;mm<sup>2</sup>. The smaller cross sections are made of 19 strands, whereas the bigger has 37 strands.
Two standard configurations for main lines consist of two contact wires of 100&nbsp;mm<sup>2</sup> and one or two catenary wires of 120&nbsp;mm<sup>2</sup>, totaling 320 or 440&nbsp;mm<sup>2</sup>. Only one contact wire is often used for side tracks.<ref>{{cite act | index = 2610-5/2003/3-0503 | date = {{date|2003-05-23|mdy}} | title = Pravilnik o projektiranju, gradnji in vzdrževanju stabilnih naprav električne vleke enosmernega sistema 3 kV | trans-title = Rules on the design, construction and maintenance of stable 3 kV DC traction devices | url = https://www.uradni-list.si/glasilo-uradni-list-rs/vsebina/2003-01-2787/pravilnik-o-projektiranju-gradnji-in-vzdrzevanju-stabilnih-naprav-elektricne-vleke-enosmernega-sistema-3-kv | language = sl
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In the [[United Kingdom|UK]] and [[Member state of the European Union|EU countries]], the contact wire is typically made from copper alloyed with other metals. Sizes include cross-sectional areas of 80, 100, 107, 120, and 150 mm<sup>2</sup>. Common materials include normal and high strength copper, copper-silver, copper-cadmium, copper-magnesium, and copper-tin, with each being identifiable by distinct identification grooves along the upper lobe of the contact wire. These grooves vary in number and location on the arc of the upper section.<ref>BE EN 50149:2012, Railway applications - Fixed installations - Electric traction - Copper and copper alloy grooved contact wires, BSI Standards Publications</ref> Copper is chosen for its excellent conductivity, with other metals added to increase tensile strength. The choice of material is chosen based on the needs of the particular system, balancing the need for conductivity and tensile strength.