Description: This sound is a massive furnace and some large machines running in a large factory.

Description: Sound of some gears winding down.

Description: Sound of a pump or motor running.

Description: A vehicle engine running.

Description: A low vibrating humming sound.

Description: The sound of a platform or a forklift changing elevation.

Description: Sound of a machine running, or a truck engine.

Description: A large engine pumping or something large spinning.