That’s also kinda why tanks are called tanks today.

When the British were building the Mark I Landship (world’s first “tank”) it was a top secret project. However there were hundreds of civilian workers working on the assembly lines. Expecting that workers would start questioning about what they were building, the British war department told the workers that they were building “water carrying tanks”.

Then since no popular formal name was given to the new armoured vehicles, the name “tank” stuck.