Installation of the steelwork platform provides access to the inner surface of the eastern semi-dome.
A new phase is beginning in the restoration of Hagia Sophia Grand Mosque, with a steel platform to be installed to strengthen the eastern semi-dome, identified as the structure’s most vulnerable section.
The building is undergoing the most comprehensive restoration project in the history of the republic, with structural strengthening to be followed by extensive restoration and conservation of mosaics, decorative paintings and marble surfaces.
Architect Hasan Fırat Diker, a member of the Scientific Committee overseeing the project, said the eastern semi-dome was the most vulnerable part of Hagia Sophia and the point where a potential collapse could first begin in the event of an earthquake.
Diker said scaffolding would be installed inside the building for the work on the eastern semi-dome without preventing worship or visits.
“The exterior of the main dome has been completely covered. We will continue this process at the eastern semi-dome and observe the necessary interventions. We will strengthen the connection between the eastern semi-dome and the main dome,” Diker said.
He described the work as one of the most important stages of the restoration.
“The main dome is supported by four large arches and the most delicate of these arches is the one connecting the eastern semi-dome to the main dome. Therefore, we had to give priority to this area. For this reason, the restoration process will continue both from above, together with the main dome and the protective covering to be installed, and from inside, enclosing the dome from the interior,” he said.
Diker said no restoration project on such a scale had previously been carried out as a comprehensive whole at Hagia Sophia during the Republican period, adding that previous repairs had mostly involved localized interventions.
The current restoration covers both structural strengthening and the conservation of the building’s original decorative elements. Diker said the aim was to complete the work without unnecessarily prolonging the process.
He said many stages of the restoration were expected to be completed next year and asked those using Hagia Sophia for worship and visits to be patient during the works.
The Culture and Tourism Ministry said members of the Scientific Committee had assessed the strengthening, restoration and conservation works being carried out at the monument.
Civil engineer Mehmet Selim Ökten, a member of the committee, said numerical modeling and structural analyses had shown that the main dome needed to be strengthened together with the semi-domes.
“To carry out these procedures and restoration interventions safely and in accordance with regulations, the scaffolding system was planned and a protective dome system with a membrane covering was installed,” Ökten said.
Art historian Asnü Bilban Yalçın said Hagia Sophia had undergone repairs throughout its 1,500-year history due to structural problems.
She said the current project aimed to strengthen the structure using modern knowledge and technology, with the dome, semi-domes and exedrae all planned to be reinforced.
Structural safety and conservation
Materials scientist and chemist Ahmet Güleç said the platform and scaffolding system would also help protect the mosaics and central inscription inside the dome.
He said an additional scaffolding system installed on the platform had provided access to the entire inner surface of the dome, allowing experts to begin inspections, cleaning and conservation work on the mosaic surfaces.
When the lead covering of the main dome is removed, samples of mortar, plaster and similar building materials will be taken and analyzed, he said. The results will be used to determine the materials for conservation work.
Architect Can Şakir Binan, a member of the Scientific Committee, stressed that all interventions should follow fundamental conservation principles.
He said ensuring structural safety was a priority but stressed that this should be carried out alongside the preservation of the building’s mosaics, decorative paintings, marble coverings and traces of historical repairs.
He added that interventions should be based on scientific research and detailed documentation, carried out with the least possible intervention and with original materials preserved in place wherever possible
Mosaic conservation is continuing on the steel platform installed for work on the main dome. Experts are carrying out dust cleaning and “facing,” a procedure in which mosaic surfaces are temporarily supported with fabric to protect them.
The temporary steel roof over the main dome has been completed.
