[mellavora]

Camel trains? Mule trains? thought trains?

Etymology 1 From Middle English trayne (“train”), from Old French train (“a delay, a drawing out”), from traïner (“to pull out, to draw”), from Vulgar Latin traginō, from tragō, from Latin trahō (“to pull, to draw”), ultimately from Proto-Indo-European *tregʰ- (“to pull, draw, drag”). The verb was derived from the noun in Middle English. (https://en.wiktionary.org/wiki/train)

A group of people following an important figure such as a king or noble; a retinue, a group of retainers. [from 14th c.] A group of animals, vehicles, or people that follow one another in a line, such as a wagon train; a caravan or procession. [from 15th c.] The men and vehicles following an army, which carry artillery and other equipment for battle or siege. [from 16th c.]

lots of trains don't go on rails.