Post -by Gautam Shah
Doors’ openings have to carry the load of upper structure. Square headed doors had lintel-beams of wood or stone beams that spanned 2 to 3.5 mts. For larger spans the openings were corbelled (stepped -projecting masonry from both ends). In spite of corbels creating a triangular head, the actual door remained square cornered. For very wide openings, masonry in arch form was used. During the middle ages a variety of arches were used, like: semicircular, elliptical, 2/3/4/5 centered, rampant, compound and interlaced and flat. Materials of arch construction were mainly stones and burnt bricks. Roman arched gateways were typically 4 to 7 mts. in the span, though in public buildings concrete arched vaults of very large spans were used. Pointed arches allowed spanning different widths, yet remain within the required height.
Pointed arched openings were larger at top increasing the size of transom lite opening, and the lower or door level (i.e. below the arch spring line) the section was narrowed. The resultant horseshoe shape was slightly defiant of gravity and looked delicate, as in middle-east architecture.
Walls around the openings, like Doors and Windows were massive but often of rubble or irregularly coursed masonry. These were unreliable to carry heavy loads of entities such as lintels, arches, etc. To carry the loads door surrounds of better materials and with properly organized joints were created. The door surround was masonry framing against which the pivoted door shutters were abutted. However, Gothic period (and equivalent time in other cultures) saw well-layered wall masonry, and replacement of door surrounds with wood frames for fixing hinged doors. Wood door frames were non-load bearing elements placed for ‘hanging’ the hinged door shutters, and so were just minimal in size. Rest of the opening sides were covered with casings (a type of door side panelling).
The upper sections of the arched openings for windows were filled with traceries or, i.e. pierced panels as a continuation of the pattern from lower section. However, in the upper parts of doors openings, very often a solid panel was inserted like a tympanum. The tympanum panel was a separate piece, usually placed over a lintel. So a Gothic opening had arch spanning the door portal, and an inset lintel spanning the door opening. The dual arrangement for support allowed the Gothic door surround to have chamfered corners or have a serrated form.
In Gujarat and other parts of western India a stylized stone archway -Toran is placed as door head. A Toran is a set of inclined brackets that additionally support the centre of the square headed beamed opening, and pass the load to columns. Toran acquired status equal to the threshold as a metaphysical entrance. The metaphoric presence of a Toran marked the entrance. Decorative Toran of glass beads, glass tubes, embroidered cloth, flowers, leaves, coconuts, etc. are hung even today to signify a door during celebrations on auspicious occasions.