A trapdoor or hatch 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 A gallows (or less precisely scaffold) 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 sa ...

, cargo ships,

trains A train (from Old French , from Latin">-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , from Latin , "to pull, to draw") is a series of connected vehicles th ...

booby traps A booby trap is a device or setup that is intended to kill, harm or surprise a human or an animal. It is triggered by the presence or actions of the victim and sometimes has some form of bait designed to lure the victim towards it. The trap may b ...

, and more recently theatre and films.

History

Originally, trapdoors were sack traps in mills, and allowed the sacks to pass up through the mill while naturally falling back to a closed position. Many buildings with flat

roof A roof (: roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of tempera ...

s have hatches that provide access to the roof. On

ship A ship is a large watercraft, vessel that travels the world's oceans and other Waterway, navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally disti ...

s, hatches—usually not flush, and never called trapdoors—provide access to the deck.

Cargo ship A cargo ship or freighter is a merchant ship that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the world's List of seas, seas and Ocean, oceans each year, handling the bulk of international trade. ...

s, including

bulk carrier A bulk carrier or bulker is a merchant ship specially naval architecture, designed to transport unpackaged bulk cargo—such as Grain trade, grain, coal, ore, steel coils, and cement—in its cargo holds. Since the first specialized bulk carrie ...

s, have large hatches for access to the holds.

Gallows

Most 19th- and early 20th-century

featured a trapdoor, usually with two flaps. The condemned was placed at the join. The edge of a trapdoor furthest from the hinge accelerates faster than gravity, so that the condemned does not hit the flaps but falls freely.

Coffins

In 1784, the reusable economy coffin was mandated by

Joseph II, Holy Roman Emperor Joseph II (13 March 1741 – 20 February 1790) was Holy Roman Emperor from 18 August 1765 and sole ruler of the Habsburg monarchy from 29 November 1780 until his death. He was the eldest son of Empress Maria Theresa and her husband, Francis I, ...

. The coffins had a trapdoor in their base. The coffin would be lowered into the grave and a lever operated that opened the trapdoor, allowing the body to fall to the bottom of the grave.

Railways

The term trapdoor also refers to a plate in the entry vestibule of a passenger railcar that permits access to high-level platforms when lying flat against the floor of the car, and which can be flipped open to expose steps for accessing ground-level platforms. Many American commuter railroads which operate the

Comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...

railcars made by Bombardier have trapdoors to accommodate passengers boarding and alighting on both high-level and ground-level platforms.

Amtrak The National Railroad Passenger Corporation, Trade name, doing business as Amtrak (; ), is the national Passenger train, passenger railroad company of the United States. It operates intercity rail service in 46 of the 48 contiguous United Stat ...

's Viewliner,

Amfleet Amfleet is a fleet of single-level intercity railroad passenger car (rail), passenger cars built by the Budd Company for American company Amtrak in the late 1970s and early 1980s. Budd based the Amfleet design on its earlier Budd Metroliner, Me ...

, and

Horizon The horizon is the apparent curve that separates the surface of a celestial body from its sky when viewed from the perspective of an observer on or near the surface of the relevant body. This curve divides all viewing directions based on whethe ...

railcar fleets all have trapdoors.

Biology

Trapdoor spiders hide in an underground nest they line with their silk, and then conceal it with a hinged silk lid, the trapdoor.

Star traps in theatre

In theatrical use, "star traps" allowed explosively fast appearances on stage, such as

jinn Jinn or djinn (), alternatively genies, are supernatural beings in pre-Islamic Arabian religion and Islam. Their existence is generally defined as parallel to humans, as they have free will, are accountable for their deeds, and can be either ...

appearing in a puff of smoke.

Fiction

Trapdoors are occasionally used as hidden doors in fiction, as entrances to

secret passage Secret passages, also commonly referred to as hidden passages or secret tunnels, are hidden routes used for stealthy travel, escape, or movement of people and goods. They are sometimes inside buildings leading to secret rooms. Others allow pe ...

ways,

dungeons A dungeon is a room or Prison cell, cell in which prisoners are held, especially underground. Dungeons are generally associated with medieval castles, though their association with torture probably derives more from the Renaissance period. An o ...

, or to secret

tunnel A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ve ...

s. They also appear as literal traps into which a hapless pedestrian may fall if they happen to step on one. Different types of doors or other objects are also sometimes used as hidden doors. A trapdoor figures prominently in a late scene of the 1963 film '' Charade''.

References

External links

{{Commons category-inline, Trapdoors Doors Parts of a theatre