By Geoff Clifton and Gary Willis
The Structural Engineer (2007)
Introduction: The first Norman Cathedral in Lincoln was built between 1072 and 1092; this building was partially reconstructed from 1141 after a fire, but was then severely damaged in an earthquake in 1185. The Cathedral was then rebuilt in Gothic style from 1192. The Dean’s Eye rose window is located in the North gable wall of the Great North West Transept and was constructed as part of this reconstruction in 1220. The window has a daring structural concept and there is evidence that it required strengthening from an early period. It is likely that the form of the window was decided upon by a cleric or a glazier without any advice from a mason, hence its lack of structural integrity. Its companion window, the Bishop’s Eye, in the South Transept required rebuilding in 1330, though whether the original design was similar to that of the Dean’s Eye is unknown.
The Dean’s Eye window, has had many interventions over the years with repairs to the jointing, replacement stones and iron bracing, though the original glass has survived throughout. By 1990 the ornately carved stone tracery, which forms the individual glazed openings and the structural skeleton for the window, was in a very poor condition. The number of fractures and displacements leading to a real danger of collapse. In the early 1990s the glazing was removed for conservation and the process started to consider what should be done with the tracery. By 2000, after much discussion and debate, it was agreed by English Heritage (EH) and the Cathedral Fabric Commission for England (CFCE) that the tracery was in such poor condition that it had to be replaced and that the replacement should aim to do away with the external ironwork that was supporting the fractured stonework.