If one contact shoe of a car is touching the third rail, how many contact shoes on that car are alive?

In a typical train system that uses a third rail for electrical pickup, each rail car is equipped with contact shoes designed to draw electrical power from the third rail. The configuration usually includes two contact shoes on each side of the car connected to the electrical system, which means that when one of these shoes makes contact with the third rail, it establishes a path for electrical current.

When one contact shoe is touching the third rail, that shoe is "live," meaning it is actively conducting electricity. However, since there are two contact shoes per side and potentially two sides, as long as the car is equipped with four contact shoes in total, at least one shoe on each side might also be functional depending on the rail system's configuration. This means that when one contact shoe is grounded, the other shoes can also be functional. Consequently, in the case where one shoe is in contact, both shoes on that side could also be considered "alive" although only one is confirmed to be in contact.

Thus, if we're considering the total number of live contact shoes from both sides of the car that could realistically provide a connection to power, the total would be four. This highlights how electrical systems in trains can allow for redundancy, ensuring that if one shoe fails or