third rail
type of electricity transmission of railways, particularly common in metro networks, one pole has a third rail, and the other pole is grounded and connected to the two primary rails
en-US/ˈθɝd ˈɹeɪl/
en-GB/ˈθɜːd ˈɹeɪl/
type of electricity transmission of railways, particularly common in metro networks, one pole has a third rail, and the other pole is grounded and connected to the two primary rails