A £5 million project to conserve one of the largest surviving narrative stained glass windows in the world has begun at York Minster.
Experts have started to remove all 152 panels from the St Cuthbert Window – many of which are nearly 600 years old – to be cleaned and repaired.
The five-year programme will also see urgent work carried out to replace and repair eroded and decaying masonry surrounding the window in the Minster’s South East Transept.
Experts from the York Glaziers Trust will remove and clean the glass panels, stabilising any cracked and broken glass and lead, before returning the window with a state-of-the-art protective glazing to help keep the glass dry.
Professor Sarah Brown, director of the Trust, said: “This gives us the opportunity to do the first piece of serious conservation since the immediate post-war period and so we’re launching this programme of cleaning, stabilisation and then, most importantly, we’ll be bringing the conserved window back with state-of-the-art protective glazing.”
She continued: “We’re also mending leads where we’re able to do so, so that parts of the narrative will be a great deal clearer, and we’re also stabilising cracked and broken glass and any cracks in the lead matrix that holds the whole window together.
“But I think it’s generally the lightening of the whole window that will be the greatest benefit.”
Sorted for 100 years
Prof Brown said she hopes the protective glazing will mean the window does not require any further repairs for at least the next century.
“Their greatest enemy, ironically, is moisture,” she said. “The kind of protective glazing we will install will effectively keep the glass dry on both surfaces, so we’re hoping that, with a stable environment, the glass will last for hundreds of years before attention is needed again.”
The removal of the glass will allow experts to carry out a survey of the surrounding stonework and finalise plans for the renewal of weathered stone.
Alex McCallion, director of works and precinct at York Minster, said: “It’s a £5 million project in total and you can see the state of the stone.
“We’re downwind of four coal-fired power stations so we’re seeing the effect of centuries of erosion and corrosion.”
He added: “We work in 100-year scaffold cycles so there won’t be scaffolding up here for another 100 years so we will leave stone on the building that we think has 100 years left in it.”
People can support the project by adopting a piece of the window’s stained glass – some of which will go on display inside the cathedral at an exhibition in June – or by donating at one of the digital donation points around the Minster.
Mr McCallion said: “Essentially what we are doing is ensuring the Minster is in a better state than we found it for future generations to enjoy it as we do today.”