Bridges types - Generalities and definitions
(According to courses from "Public Works' Special School of Paris" - Teachers : Mr Deloupe et Honoré 1939)
Depending on the point of view of their importance , Bridges are subdivided into:
"Culverts," bridges , viaducts and aqueducts.
- A"culvert " is a very small arch bridge of less 4m of opening, comprising only two supports and usually built on a small ravine, a brook etc.
-A bridge is a work sometimes very important, but having for object the crossing of only one obstacle (river, railway, road...)
They can be classified in the following way:
- Fixed bridges, allowing a continuous circulation.
- The moving bridges (swinging or travelling or lifting...), established at a given point in order to be able to stop circulation temporarily, to be able to leave passage to the boats, trains or other vehicles, according to the nature of the way crossed by these bridges .
-- the "flying bridges" which one can move at will...
- A viaduct is a structure sometimes considerable, composed of arches or spans many and raised, sometimes on several stages of vaults, and intended to cross great spaces, valleys, large ravines etc
-An aqueduct is a work of weak opening, which is used only in the passing of water.
whether one considers them from the point of view of the nature
of the ways to which they give access, one divides them into:
My classification was carried out primarily according to the types of representations met on the stamps and philatelic documents found with the wire of my research. Consequently It borrows a little from each one of these classifications, in a strict didactic preoccupation of clearness and balance...
References of the stamps: The
majority correspond to N° of the French catalogue Yvert and Tellier
but also with the American catalogue Scott (Sc)
and also with the German catalogue Michel (Michel)