Notre Dame undergoes risky repairs as workers remove melted scaffolding from roof

Workers have started removing scaffolding from Notre Dame. Photo / AP file

A high-risk operation likened to "open-heart surgery" has begun on the roof of Notre Dame cathedral to remove tons of mangled scaffolding that melted in last year's devastating fire and still threatens the building with collapse.

Some 40,000 metal tubes weighing 200 tonnes had been erected atop the Gothic building to repair its spire and roof before the blaze last April. Most of the structure melted and fused in the intense heat, posing a fiendish conundrum to restoration workers. The spire and roof were destroyed.

Starting from today, two five-man teams will be lowered by ropes from a crane to start carefully sawing off sections of the scaffolding.

Christophe Rousselot, the director-general of the Fondation Notre Dame, the charity overseeing the collection of donations to the cathedral, said: "It's a bit like open-heart surgery because we are in the middle of the cathedral between the transept and its heart, precisely where the spire crashed down."

Rousselot also likened removing the tubes to Jenga, the game in which players seek to remove blocks from a tower without the entire structure crashing down.

"In a building like this, you never know what might happen when you take one part away rather than another," he told the Daily Telegraph. "We're not dismantling the thing in one go but cutting out pieces that will then be removed by an 80m-high crane."

Delicate work of removing melted scaffolding from Notre-Dame cathedral in Paris gets under way https://t.co/gOanxLbOwA

— BBC News (World) (@BBCWorld) June 8, 2020

The scaffolding was heated to temperatures of 800 degrees Celsius during the blaze, some 40m up, and has been melded to the cathedral's limestone walls, which have been weakened.

"Every precaution has been taken and it has been minutely prepared for months, but we cannot rule out difficulties in such a complex operation," Rousselot said.

To avoid further damage, nets have been erected to protect the north and south gables in case chunks of stone fall when the scaffolding is cut.

The operation is due to last at least three months, but Rousselot said that, given the complexity, "we cannot rule out further delays". Until this giant "spider's web" is removed, other major repair work cannot commence.

"We will know whether the cathedral is in a sufficiently good state to have a new roof and frame at the end of 2020 when this first operation is deemed a success," he added.

Workers began to dismantle the 200 tons of metal scaffolding on the Notre Dame cathedral in Paris after the fire that destroyed parts of the iconic landmark in April 2019, resuming renovations since pausing due to COVID-19. https://t.co/kdgnzMtmYh pic.twitter.com/DQL3ps11g0

— ABC News (@ABC) June 8, 2020

Millions around the world watched in horror as the blaze tore through the cathedral's roof last year, causing its steeple to collapse.

Firemen narrowly averted total collapse of the building after battling the flames throughout the night, but the structure remains at risk. Since then, the cathedral immortalised by Victor Hugo has received around a billion euros in donations.

Emmanuel Macron, the French President, has controversially pledged to complete the restoration of Notre Dame by 2024, in time for the Paris Olympics. However, work has already suffered delays due to lead pollution from the blaze, bad weather and now the coronavirus pandemic.

While optimistic that the cathedral would be partially reopened for the occasional service well before 2024, Rousselot said its full restoration could take a decade.

"Other cathedrals have sadly burned. When the one in Nantes was cut into two, the nave and transept continued to be restored for more than 10 years and just one part of the cathedral was open to the public. That may also be the case for Notre Dame," he said.