A technical product

Usefull for sewers cleaning.

These MANHOLE COVERS allow, according to the size of the gallery on which they are placed, to go down there using a scale or to check of it from surface the good inventory of fixtures. For this they pullulate in our streets in order to offer an easy access, in particular at crossing points of galleries.

From 1934's catalog of Société des Fonderies de Bayard et Saint-Dizier (France).

They are composed of 2 parts : A square framework sealed on the ground and offering a centered round opening of a sufficient diameter to allow the passage of a man - the " inspection pit " - and the buffer to close this opening. The circular shape of the opening guarantees that the buffer then to fall through the opening, since this one is equipped with an edge, on which rests the buffer, is thus narrower.

Rather than of simple smooth plates and thus dangerously slipping for circulation during wet or icy weather, they offer on their surface a series of shapes of which quite relative roughness goes slowly softened by the passages. All the more easily, moreover, that the cast iron is a material less hard than steel.

From 1934's catalog of Société des Fonderies de Bayard et Saint-Dizier (France).

Certain models include several holes in the shape to allow the ventilation of the gallery which they close. (This is particularly visible in Lyon, as you will see on photo n° 19, and Beaune).

Manhole covers at Carcassonne (Aude).