fusepark

Years ago my father gave me a couple of odd devices. Only nine or ten inches long, heavy iron or steel, handles dipped in plastic, the heads looked like offset socket wrench heads. I couldn't guess what they were for. He said they were "keys" or levers that train engineers used to start their train engines. Or at least, to unlock the security on the engines. Something along those lines.

What are these called? Are they still used? If not, what were the last trains to use them? Many thanks!