A trapdoor is a sliding or hinged door that is flush with the surface of a floor, ceiling, or roof. It is traditionally small in size. It was invented to facilitate the hoisting of grain up through mills, however, its list of uses has grown over time. The trapdoor has played a pivotal function in the operation of the gallows, cargo ships, trains, booby traps, and more recently theatre and films.
A trapdoor to a bomb shelter from World War II
Deck hatch of the Omega, the last square-rigged sailing cargo ship
Amtrak conductors standing in the doorways of Amfleet cars with their trapdoors in the closed (above) and open (below) positions
19th century Star trap from the Theatre Royal, Drury Lane, London, Now at the Victoria and Albert Museum
A gallows is a frame or elevated beam, typically wooden, from which objects can be suspended or "weighed". Gallows were thus widely used to suspend public weighing scales for large and heavy objects such as sacks of grain or minerals, usually positioned in markets or toll gates. The term was also used for a projecting framework from which a ship's anchor might be raised so it is no longer sitting on the seabed, riverbed or dock; "weighing [the] anchor" meant raising it using this apparatus while avoiding striking the ship's hull.
Unidentified men wait at the gallows before execution of Melquiades Chapa and Jose Buenrostro on May 19, 1916, in Brownsville, Texas.
Illustration of hanging during the Thirty Years' War
These gallows in Tombstone Courthouse State Historic Park are maintained for historical purposes by Arizona State Parks.
New Drop gallows in Rutland County Museum