King post
Encyclopedia
Vertical direction
In astronomy, geography, geometry and related sciences and contexts, a direction passing by a given point is said to be vertical if it is locally aligned with the gradient of the gravity field, i.e., with the direction of the gravitational force at that point...
supporting post used in architectural
Architecture
Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...
, bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
, or aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
design applications.
Architecture
Beam (structure)
A beam is a horizontal structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a bending moment.- Overview...
to the apex
Apex (geometry)
In geometry, an apex is the vertex which is in some sense the highest of the figure to which it belongs.*In an isosceles triangle, the apex is the vertex where the two sides of equal length meet, opposite the unequal third side....
of a triangular
Triangle
A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted ....
truss
Truss
In architecture and structural engineering, a truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in...
. The king post connects the apex of the truss with its base, holding up the tie beam at the base of the truss. King posts were used in roof
Roof
A roof is the covering on the uppermost part of a building. A roof protects the building and its contents from the effects of weather. Structures that require roofs range from a letter box to a cathedral or stadium, dwellings being the most numerous....
construction in Medieval architecture
Medieval architecture
Medieval architecture is a term used to represent various forms of architecture common in Medieval Europe.-Characteristics:-Religious architecture:...
in buildings such as parish church
Parish church
A parish church , in Christianity, is the church which acts as the religious centre of a parish, the basic administrative unit of episcopal churches....
es and tithe barn
Tithe barn
A tithe barn was a type of barn used in much of northern Europe in the Middle Ages for storing the tithes - a tenth of the farm's produce which had to be given to the church....
s, and also appear in Gothic Revival architecture
Gothic Revival architecture
The Gothic Revival is an architectural movement that began in the 1740s in England...
and Queen Anne architecture. A similar structure may be used to construct a simple bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
.
A development of the king post structure terminates the central post before it reaches the apex of the roof truss. Instead, the king post is held in place by a collar beam, a secondary beam parallel to the tie beam. In this structure, the central post is termed the crown post.
Queen post
A queen post is a supporting post designed to span longer openings than a king post. A king post uses one central supporting post, whereas the queen post uses two.-Architecture:...
s (or queen-posts). These vertical posts, positioned along the base of the truss, are supported by the sloping sides of the truss, rather than reaching its apex. A development adds a collar beam above the queen posts, which are then termed queen struts. A section of the tie beam between the queen posts may be removed to create a hammerbeam roof
Hammerbeam roof
Hammerbeam roof, in architecture, is the name given to an open timber roof, typical of English Gothic architecture, using short beams projecting from the wall.- Design :...
.
Norman truss
Architectural historians in LouisianaLouisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
use the term "Norman roof" to refer to a steeply-pitched roof; it is supported by what they call a "Norman truss". This is a through-purlin
Purlin
In architecture or structural engineering or building, a purlin is a horizontal structural member in a roof. Purlins support the loads from the roof deck or sheathing and are supported by the principal rafters and/or the building walls, steel beams etc...
truss consisting of a tie beam and paired truss blades, with a central king post to support the roof ridge. The name derives from a belief that this system of construction was introduced to North America by settlers from Normandy
Normandy
Normandy is a geographical region corresponding to the former Duchy of Normandy. It is in France.The continental territory covers 30,627 km² and forms the preponderant part of Normandy and roughly 5% of the territory of France. It is divided for administrative purposes into two régions:...
in northern France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, but it is really a misnomer as the system was more widely used than that.
King post truss
Rafter
A rafter is one of a series of sloped structural members , that extend from the ridge or hip to the downslope perimeter or eave, designed to support the roof deck and its associated loads.-Design:...
s, and the horizontal member may serve as a ceiling joist
Joist
A joist, in architecture and engineering, is one of the horizontal supporting members that run from wall to wall, wall to beam, or beam to beam to support a ceiling, roof, or floor. It may be made of wood, steel, or concrete. Typically, a beam is bigger than, and is thus distinguished from, a joist...
. A bridge would require two king post trusses with the driving surface between them. A roof usually uses many side-by-side trusses depending on the size of the structure.
Marine Engineering
On a cargo shipCargo ship
A cargo ship or freighter is any sort of ship or vessel that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the world's seas and oceans each year; they handle the bulk of international trade...
a king post is an upright with cargo-handling devices attached to it. Since king posts are designed for handling cargo, they are located at the forward or after end of a hatch.
Aviation
Flying wires
The flying wires of an aircraft work in conjunction with other wing components such as spars and interplane struts to transmit flight loads. Most commonly used on biplane aircraft they are also used on monoplanes and triplanes.-Purpose:...
aircraft, where the king post supports the top cables or "ground wires" supporting the wing.