Amiens Cathedral (Ascent) triforium

East side of the upper south transept

The three bays of the main arcade were built by Master Thomas in the 1240s: it is in the triforium here that Thomas's adventurous son, Renaud, began his experiments with a glazed triforium in the 1250s. His first essays incorporated the same great trefoil his father had used: but instead of the more substantial plate tracery of the earlier work young Renaud preferred fragile sticks of stone or bar tracery. The innermost bay adjacent to the crossing is inherently unstable and the fragile composition has failed very soon after its initial installation and has been replaced by a much more dense composition with smaller trefoils.

Consolidation in South Transept

Consolidation in South Transept

Cracks in the Arcade

Cracks in the Arcade

Cracks in the Triforium

Cracks in the Triforium