Thursday, September 26, 2013

Restoration in Longford: raising St Mel’s cathedral from the ashes

http://www.irishtimes.com/polopoly_fs/1.1539803.1380122719!/image/image.jpg_gen/derivatives/box_620_330/image.jpgOn Christmas Day 2009, Kevin Fay stood at the entrance to St Mel’s Cathedral in Longford and watched in horror as snow fell on the still smouldering shell of the burnt-out building which has dominated the local skyline since the 1850s. 

The cathedral roof was gone, the floor had collapsed into the crypt, and so intense was the heat that marble fittings had melted.

“The stone was still so hot that the snow made a crackling noise when it fell,” recalled structural engineer Fay, who had been an altar boy in the cathedral.

He is now director of the €30 million St Mel’s conservation project, described as the largest of its kind in western Europe.

A few hours before the fire hundreds of local people had attended Midnight Mass in St Mel’s which was celebrated by Bishop of Ardagh and Clonmacnoise Dr Colm O’Reilly, a driving force behind the restoration initiative.

Sparked by an electrical fault in a boiler, one of the reasons the inferno was so unforgiving was that the copper roof expanded, creating a furnace beneath it where the temperature climbed to 1,100 degrees Celsius. 

It later emerged that a painting of the Holy Family survived the blaze, although the canvas was just a few feet from a marble altar which “sugared” in the heat .

“Normally the roof would collapse, letting the heat out,” explained Fay, a director of local construction company Gem Group.

It has teamed up with Purcell Construction from Galway for this massive restoration job which is showcasing the skills of over 125 craftsmen, many from the diocese.

St Mel’s is a protected structure which luckily was fully insured. The foundation stone was laid in 1840, work stalled for 10 years during the Great Famine, and it would be decades before its distinctive Italianate bell tower, which survived the blaze, and the imposing portico were finished.

The deadline for Gem Purcell is somewhat tighter as the diocese has announced that Midnight Mass will be celebrated in St Mel’s on Christmas Eve 2014.

The restoration and conservation challenge was entrusted, in February 2011, to the architect Dr Richard Hurley, who has since passed away, and Colm Redmond, of Fitzgerald, Kavanagh & Partners, is now the lead architect.

The challenge for Gem Purcell, who came on board in September 2012, has also been immense, and on Sunday next, as part of St Mel’s Festival, the professionals will allow the public to view this work in progress during a cathedral open day.

With the Christmas 2014 deadline focusing minds, Gem Purcell came up with a number of ingenuous ways of meeting the massive logistical challenges.

Given that there was no floor, no roof and that the 28 hand-carved limestone columns which supported the structure were effectively destroyed, they devised a system which allowed the delicate restoration work to proceed on three levels at the same time.

“We effectively had three building sites, one above the other,” explained Martin Healy, managing director of Gem, which has previously worked on projects at Dublin Castle and Government Buildings.

With no floor to support scaffolding a suspended steel support “bridge” was constructed which allowed one team to work on the roof while below the delicate task of replacing the columns continued alongside the “ defrassing” of the fire-damaged internal masonry walls. 

This process involved removing and replacing by hand any blemished stones .

Meanwhile a concrete floor was laid while an army of skilled plasterers set about recreating traditional cornices in the basement where local clergy were once laid to rest in vaults. 

The hand-crafted decorative plaster being created on-site will be used for niches, architraves for the Diocletian windows and side aisles, and for the cathedral’s distinctive barrel vaulted and flat ceilings .

“I think the term tradesmen does not do justice to these people,” said Michael Bane, head of Purcell Construction which has worked on a number of landmark public buildings, including Sligo and Tullamore courthouses. 

“They are artists – they take so much pride in their work.”

It’s hard to get across the scale of the task of replacing the 28 blue limestone columns which measure eight metres high, each one consisting of a decorative capital, a fillet stone, four intermediate drums and a base.

“The individual drums weigh over three ton each,” explained Fay. Quarrying pieces that size was one problem. Getting them into the building was another mammoth task, especially given that a temporary roof had to be erected to protect the ongoing delicate work below.

The sections, protected by safety harnesses, had to be hoisted by crane through a “sliding door” in the temporary roof without damaging the stone. 

Many anxious hours were spent devising a way to manoeuvre out the damaged columns while manipulating in the replicas.

The figures are illuminating. 

At this stage 675 tons of native blue limestone from Leighlin, Co Carlow, has been installed – for the columns, the hand-carved window surrounds, pilasters, and for replacement corbels for the bell tower which did sustain some damage.

To get this amount of limestone in the section sizes required, a staggering 10,400 tons had to be quarried. 

Those replacing the columns discovered that some of their predecessors from the 1800s had left their names on their work. 

“It reminds us that what we are doing today will be the history of tomorrow,” said Fay.

Approximately 70 tons of lead will be used to form roof valleys, parapets, copings, gable walls and rainwater outlets.

For the barrel vaulted ceiling traditionally designed timber queen trusses measuring over 14m are being used instead of steel beneath the plaster. 

The trusses were made using traditional mortice and tenon jointing techniques, as stipulated by An Bord Pleanála, and special trolleys manoeuvred them into position along the reinstated nave limestone copings.

While there was a copper roof on the cathedral at the time of the fire, the design team discovered that the original roof was made of blue Bangor slates from Wales. 

Amazingly the receipt for these slates was found and replacement slates sourced from the same quarry which did business with the diocese in the 1800s.

When St Mel’s reopens its door on Christmas Eve next year there will be new features such as a central altar (one seven-ton slab of Carrara marble) underground heating and a glass lift.

St Mel’s crozier, reputed to be 1,000 years old, may have perished in the blaze, but the congregation will be relieved to see the return of familiar features like the Harry Clarke stained glass windows and the imposing columns, complete with 28 faithfully restored hand-carved angels each with a different face.

“We expect 3,000 people to come on Sunday to see what has been done so far,” said Fay. “We hope what they see will give them hope and encouragement.”