Façade of St. Peter’s Basilica in the Vatican is getting a face-lift with the help of infrared thermography.
Infrared thermography is being used to control the physical
characteristics and to determine the state of preservation of the Façade
of the St. Peter’s Basilica in Rome. This Basilica is widely recognised
as the centrepiece of Christianity and the Vatican City.
In the year 323, a sanctuary, built in the form of a cross, was
constructed to commemorate the crucifixion of the Apostle Peter. By the
fifteenth century, the decay of this monument had progressed to such an
alarming extent that plans were made to construct a Basilica. In 1548,
the control of this project was given to Michelangelo. He built it in
accordance with the plans created by Bramante of Florence, but
strengthened the central piers to bear a dome measuring 123.5 metres
high with an internal diameter of 42 metres.
Great emperors and most
Popes are buried in the tomb of St. Peter. In 1606, Carlo Maderno,
architect of St. Peter’s Fabbrica, won the competition to build the
extension to the Basilica. In September 1607, Pope Paul V approved the model of
Maderno’s Façade and, the following November, work began on the
foundations. Construction continued until 1615 with the stucco covering
of the vaults of the nave side aisles. The small domes of the side
aisles were finished in 1616, the same year that the new choir was
Today, the Façade of St. Peter is maintained by
‘Fabbrica di San Pietro’, an organisation of the Catholic Church. This
organisation permanently employs an elite group of architects, artisans
and workmen. Only on rare occasions has the management of St. Peter’s
agreed to seek assistance from specialists who do not belong to this
The sole scientific partner of Fabbrica di San
Pietro during the restoration of the façade of the Basilica of Saint
Peter is EniTecnologie. This customer of FLIR Systems is headquartered
in Rome. The appointment of EniTecnologie to develop and apply
innovative techniques to this restoration project was quite an honour.
Thermal images show a reccurent critical situation detected on the Façade, concerning fractures and water stagnation in stucco works (darker area)
State-of-the-art infrared technology to restore historic monuments…
In November 1997, Mr. Giunta of EniTecnologie used a
FLIR ThermaCAM™ SC 1000 on site. After seeing the enormous potential
for use of infrared cameras for building restoration, he convinced
EniTecnologie to purchase a camera. Since acquiring this ThermaCAM,
Giuseppe Giunta has been focusing intensively on the restoration and
conservation of artistic monuments.
Thermographic techniques proved to be extremely
effective in diagnosing the state of the Façade of St. Peter’s Basilica
before the restoration commenced and in verifying the quality of the
actual effort. The team from EniTecnologie was able to identify cracks,
detachments of stucco from the stone surface and deposits of humidity
that would otherwise have remained hidden.
The most significant use of thermography was in the
evaluation of the stuccos where temperature differences of 0.5 °C were
determined to be critical. Thanks to the high thermal sensitivity of the
FLIR Systems ThermaCAM, the team was able to take IR images and to
control the condition of approximately 50,000 stuccoes on the façade of
the Basilica. Infrared thermal imaging also helped the experts to
fine-tune a biocide treatment to remove the micro-organisms
that plagued a large portion of the stone surface and to verify the
effectiveness of this procedure.
… to everyone’s satisfaction
His Eminence Cardinal Virgilio Noè, president of
Fabbrica di San Pietro, is very pleased with the result and expressed
gratitude to the EniTecnologie team. “Due to the harmonic and proficient
co-operation between the technicians of Fabbrica di San Pietro and
those of the EniTecnologie group, the façade is about to be unveiled.”
He stated that the operation was delicate and complex, extremely
demanding, and that it was an important occasion to verify and confront
many different restoration methods and techniques.
The project has been categorised as a success. Mr.
Giunta recently told FLIR Systems, “Our thermographic work has been
considered very innovative and of high quality. The result of our work
has been presented to the management of the Louvre Museum in Paris and
has caught the interest of the international press.”
The project team at Eni has met its commitments
within a very challenging time frame. They concluded that: “infrared
thermography, and in particular the FLIR Systems ThermaCAM, proved to be
a virtually irreplaceable instrument in the various phases of the
project,” and that their discoveries will prove, “invaluable for
restoration work on historic monuments in the future.”
Eni is an integrated energy company, operating in
the oil, natural gas, and petrochemicals industries as well as oilfield
services and engineering, with a market presence in over 80 countries.
EniTecnologie carries out scientific and technological research,
concentrating its skills on the definition of innovative and
environmentally friendly technologies.