Man & Machine : St Albans Cathedral Martyrs

Rory Young working on one of the new Caen stone statues at St Albans Cathedral.

StoneGenie robotics have helped sculptor Rory Young create the seven medieval style Caen stone figures that now fill the niches of the rood screen in St Albans Cathedral.

Seven statues carved in French Caen limestone have been installed in the medieval niches of the rood screen that heads the nave of St Albans Cathedral. Not that you would instantly know they are stone because they have been painted in a return to a medieval tradition almost entirely eschewed since the Reformation.

Five years in planning and execution, the statues are the work of artist Rory Young, with a bit of help from the computerised 3m long robot arm at Stoneworld in Oxfordshire, with its Alphacam software, that the company has trademarked as StoneGenie.

It is estimated that carving each of the seven statues from the block by hand would have taken about eight months. Each was on the robot, which was working 24 hours a day, for about a week, following three days of preparing the programs to run the robot.

Rory Young and his assistant then spent 13 months finishing the carvings in order to achieve precisely the works that Rory and the Cathedral wanted.

The process began with drawings then 1:6 scale clay maquettes. These were scanned by Stoneworld using its £45,000 Konica Minolta photographic scanner and scaled up to be produced first in polystyrene by Stoneworld’s StoneGenie.

Rob Parker, the CEO of Stoneworld, says sculptures are quite often produced in polystyrene before being carved in stone so artists can see their work full scale before committing it to stone. The robot is charged for by the hour and polystyrene is a lot quicker to carve than stone.

At full size, Rory could see where changes needed to be made. “In the three weeks running up to the presentation of the full scale models in situ I was working 80 hours a week using plaster on the polystyrene on the hands and faces of the statues to get them right,” he told NSS.

After colouring to an agreed scheme the polystyrene statues were positioned in their niches to ensure they would fit and that they looked right.

When Rory was finally happy with them, the polystyrene statues had to be painted off-white so they could be scanned by Stoneworld to incorporate the changes and the robot could start to work on the Caen limestone.

There were too many changes to be able to use the original computer programs for the amended designs and Rob Parker says it took his brother-in-law, Steve Newbury, who programs the robot, three days to create the 40 or so new programs he needed for each of the seven statues. “We all bought these robots thinking all you had to do was scan something and let the robot get on with the carving. But they are nothing like that at all. You have to write the programs then make sure the program that runs the robot can understand it so it does not try to move from one point to another by going straight through the workpiece.”

Steve Newbury adds: “I did enough programs to get the first statue going, then when it started cutting I continued programming. It was a steep learning curve to begin with but by the time I got to the seventh statue I had it down to a fine art.”

“Each program drives the toolpaths for one tool, so I create as many programs as are necessary to ensure that each area is covered by each tool.

“The APT file is transferred into Eureka software to control the automatic turntable and approach of the robot, including speed and exit. Then everything is converted into DAT code which I load directly into the robot from my PC and it’s ready to go.”

The 36-tool autochanger selects and fits the selected tools to the spindle, so the machine never stops from the time it starts to cut the stone to the finish of the job.

Steven Newbury says artists and sculptors are beginning to see the benefits of CNC technology driven by state-of-the-art CAD/CAM software to help them with their work. And he does not believe it reduces the level of traditional skills needed for such work. “All the old traditional skills are still needed – that sense of touch and the human eye – for high quality artistic pieces.”

Once the programming was satisfactorily completed for the St Alban martyrs it took the robot five 24-hour days to produce each of the statues. The work began with an 85mm milling wheel, then continued using a 25mm router and finally an 8mm bullnose carbide bit to finish off. “When they left here they were fully identifiable as the finished sculptures,” says Rob.

Rory had covered some of the features of the polystyrene carvings, such as ears and hands, with padding under masking tape before they were scanned so the robot would leave blocks of stone where they would be, which would leave Rory the freedom to make the final decisions on these features as he finished the stone by hand.

“Everything is in the work we did by hand,” he says. “And in the design. And because we saved so much time by having the robot rough it out we could put that time into the final carving, which is all part of the finesse of the design. For instance, in the drapery I made further refinements as we were carving it; the folds were perfected with every cut.”

The robot had allowed an extra 3mm of stone all round as well as leaving stone where Rory had masked the polystyrene. It allowed plenty of scope to make the finishing touches.

Rory: “Caen stone is very fine, allowing deep undercutting, which I wanted to push to the limits. I soon developed a surfacing technique involving the use of drags to create textures such as the woven clothes. We made a range of cockscombs out of old saw blades.”

During the carving, the stone was wrapped in plastic when not being worked to stop it drying out and becoming harder to carve.

At that stage, each statue, at 80% lifesize, weighed nearly a tonne. They were hollowed out using a 50mm core drill to remove stock from the back of them, reducing the weight – 90kg was removed from the largest of them – and helping the stone to dry. The nun’s habit is hollowed out underneath and even the palm fronds, symbols of victory over death, had the stalks hollowed out and are separated from the garments behind.

Rory hand painted the sculptures with the help of several assistants. That alone took more than five months. The stone was dried over 10 days using blowers then sealed with Lascaux Hydro-Sealer, a solvent free, water-based impregnator. Next, a thin coat of Lascaux Uni-Primer was applied to act as a grip coat. The colours are Lascaux Acrylic paints.

Rory worked closely on the design of the martyrs with the Dean of the Cathedral, the Very Reverend Dr Jeffrey John, who is delighted with the result now that this long-awaited project has reached fruition.

Dr John: “Rory Young’s research has been meticulous and his workmanship of tremendous quality. The statues are a fine contemporary reworking of a medieval tradition. The installation was completed on 24 April but the statues fit and blend in so well – it feels as if they have been here for centuries.”

Rory Young said: “It was a huge privilege to win this commission and to actually work on the fabric of the building in preparation for installing the statues. It has been incredibly humbling to attempt to portray these Christian heroes.”

And for Rob Parker: “It makes us feel like it’s worth being on the planet. St Albans Cathedral is celebrating its 900th anniversary this year and these statues will be there for the next 900 years.”

There was even a nice touch of mysticism to round off the project. Just as Rory had finished carving the eyes of Elisabeth of Russia late one night a Large Emerald moth flew into the workshop and settled on the statue, like a lapel broach. It refused to move. Rory later found photographs of Elisabeth wearing a jewelled butterfly shaped pin.

The seven martyrs of St Albans Cathedral are:

  1. Oscar Romero – Roman Catholic Archbishop of El Salvador, who spoke out against poverty, social injustice and torture of the totalitarian regime in his country. He was assassinated in 1980 while celebrating Mass. The beatification for Oscar Romero was held in San Salvador on 23 May this year.
  2. St Alban Roe – a Roman Catholic, imprisoned for a time in St Albans Abbey Gatehouse and hanged for treason in London in 1642 for being a Roman Catholic priest
  3. St Amphibalus – a Christian priest given shelter by Alban in the third century AD when Christianity was still proscribed
  4. St Alban – Britain’s first saint, a citizen of Roman Verulamium, martyred by the Romans on the site of the present day Cathedral
  5. George Tankerfield – a Protestant, burnt to death in Romeland, overlooking St Alban’s Abbey, in 1555 because he refused to accept the doctrine of transubstantiation
  6. St Elisabeth Romanova – granddaughter of Queen Victoria who married into the Russian Royal Family and converted to the Russian Orthodox Church. In her widowhood she became a nun and Abbess before being killed by the Bolsheviks in 1918
  7. Dietrich Bonhoeffer – Lutheran pastor and theologian imprisoned in a concentration camp for his opposition to the Nazis, tried without witnesses or defence and hanged in April 1945

The statues are a gift from Richard and Susan Walduck, long-time friends of the Cathedral.