|■Tokyo National Research Institute for Cultural Properties
||■Center for Conservation Science
|■Department of Art Research, Archives and Information Systems
||■Japan Center for International Cooperation in Conservation
|■Department of Intangible Cultural Heritage
A glimpse of the online international training course
The Japan Center for International Cooperation in Conservation provided an online international training course, “Documentation of Cultural Heritage by Three-dimensional Photogrammetry,” on November 12th and 25th, 2020, jointly with the Japanese Centre for South Asian Cultural Heritage (JCSACH), a non-profit organization. It was aimed at promoting active incorporation of digital data as a method of international cooperation in the field of cultural heritage post COVID-19. Three-dimensional photogrammetry is a technique to create a 3D model of the exact shape of an object on a computer from photographs of the object taken from various angles by a digital camera. Since 3D models can be created using familiar equipment, such as compact digital cameras and smartphones, it is becoming popular in cultural heritage sites as a highly practical recording method. For this training course, researchers and practitioners who are responsible for the conservation of cultural heritage in four countries were invited. These included Cambodia, Nepal, and Iran, where Tokyo National Research Institute for Cultural Properties is carrying out international cooperation programs, and Pakistan, with which JCSACH enjoys close ties.
Mr. NOGUCHI Atsushi, the Director-cum-Secretary General of JCSACH, who is a leading expert in 3D photogrammetry technique in the field of archaeology, served as lecturer. In the first lecture, the trainees learned the principles of 3D photogrammetry, how to take photographs to be used for photogrammetry, and basic operation of the software. They worked on creating their own 3D models during a week of independent practice after the first lecture. In the second lecture, the trainees presented the models they had created and learned more advanced techniques, such as how to create cross-sectional views from the models.
A total of 24 researchers and practitioners from Cambodia, Nepal, and Pakistan participated in the online training course. It was unfortunate that the Iranian participants were not able to take part due to a problem with the Zoom connection, but they were provided with the course materials. Most of the trainees had never had any prior experience with 3D photogrammetry. However, they were eager to ask questions. Further, in the post-participation survey, they shared their own ideas on how to use 3D photogrammetry data, such as for recording remains at restoration sites, or for museum exhibitions.
Once 3D photogrammetry becomes a common documentation method in every country and sharing 3D information on cultural heritage becomes possible remotely, we will be able to see new developments in international cooperation projects in the future.
Study on the reinforcement measures for the foundation structure of the East Gate
The ICC Secretariat visited the restoration work site of the East Gate (courtesy of APSARA)
Tokyo National Research Institute for Cultural Properties provides continuous technical support to the Authority for the Protection and Management of Angkor and the Region of Siem Reap (APSARA) for the conservation and sustainable development of the ruins of Ta Nei Temple in Angkor, Cambodia. Last year, the restoration of the East Gate began under the Conservation and Sustainable Development Plan jointly developed by APSARA and the Institute. APSARA is responsible for securing the budget for materials and labors, as well as implementing the work. The Institute provides technical assistance on restoration methodologies and procedures, as well as cooperation in architectural and archaeological surveys before and during the work.
The possibility of our visiting Cambodia has all but disappeared after March this year, due to the global travel bans implemented to fight the COVID-19 pandemic. However, we cannot suspend the restoration work for our convenience, given that COVID-19 has not spread widely in Cambodia and the Cambodian counterpart has been continued regular site duties. From April, we have been benefiting from the advantages of Information & Communication Technology (ICT), actively utilizing interactive networking services with smartphones, besides normal e-mail messaging, to grasp real-time conditions at the site and hold online meetings as needed.
On the 21st of April, an online meeting was conducted with the East Gate restoration team of APSARA to share the result of the foundation’s geological testing during February and March and discuss restoration methods and structural reinforcement measures, based on the test result. Two of our collaborators, Professor KOSHIHARA Mikio (Structural Engineering) and Professor KUWANO Reiko (Geo-technical Engineering) from the Institute of Industrial Science, the University of Tokyo, joined the meeting. After an in-depth discussion from a scientific perspective, the participants finally agreed on a basic scheme for the restoration and reinforcement with an aim to balance heritage authenticity and structural safety. Under this basic scheme, online meetings were held in May and July to study about treating the foundation and superstructure, respectively. We had interactive discussions and shared ideas, plans, and other useful information, as well as the site’s latest condition, and decided that, at this stage, the concrete restoration/reinforcement method be considered the most appropriate one.
The Technical Session of the International Coordinating Committee for the Safeguarding and Development of the Historic Site of Angkor (ICC), organized at APSARA headquarters in June every year, was also postponed, and only the site visit by the ICC co-chairs and the secretariat was done this year. APSARA and the Institute jointly made the progress report and work plan of the project, including the activities mentioned above, and submitted it to the ICC secretariat prior to their site visit. We also held an online meeting with Professor MASUI Masaya of Kyoto University Graduate School, a member of the Ad Hoc Expert Group of the ICC, who supervised and advised us on our recent issues and the project’s work plan and exchanged information about latest information concerning international cooperation on Angkor.
In this way, we accidentally realized a potential of ICT in heritage conservation. Indeed, there is a natural limit to conservation efforts based on telecommunication and remote information sharing because the universal value of cultural heritage is in its object itself. We hope that the world returns to normal, after overcoming the COVID-19 pandemic, and the days of unrestricted international travel are back soon.
Dismantlement of the base platform.
Tokyo National Research Institute for Cultural Properties (TNRICP) has been providing technical support to the Authority for the Protection and Management of Angkor and the Region of Siem Reap (APSARA) for the conservation and sustainable development of Ta Nei Temple in Angkor, Cambodia. As a part of this project, TNRICP dispatched a total of four members, including an outside expert, to Cambodia between February 26 and March 18, 2020 for 3D documentation of the base structure and an investigation of the foundation’s strength of the East Gate under restoration.
Directed by Associate Professor Dr. OISHI Takeshi, from the Institute of Industrial Science, the University of Tokyo, a 3D laser scanning survey was conducted between February 27 and 28, 2020 to accurately record the state of the base platform including that in the excavation pits at the external corners of it, which were revealed after the superstructure was dismantled. After that, it was originally planned to conduct a flat-plate loading test and uniaxial compression test of the laterite substrate material. However, because of the spread of COVID-19, the experts in charge were unable to join the mission and only a simple dynamic cone penetration test (DCPT) was performed at the site, which was also conducted in December 2019.
DCPT was conducted at 11 points to check the bearing capacity of the soil infill inside the platform and the foundation layer at the outer edge of the platform. The outcomes of the test indicated that test points below the wall structure have generally larger values than that of the central area (under the pavement). Although the factors such as the difference in the climatic conditions at the time the tests were performed (wet and dry season) might affect the test results, the long-term structural weight causing the rammed earth beneath the walls to get compacted could have caused this distinction. It could be interpreted as the soil infill inside the platform has developed a certain degree of strength enough to support the upper weight of the structure at present. In addition to DCPT, a core sampling was also conducted with a hand auger to check the cross-sectional structure, including the lowest layer of the foundation.
Further, indoor material tests were performed by Professor Dr. KUWANO Reiko and Assistant Professor Dr. OTSUBO Masahide, from the Institute of Industrial Science, the University of Tokyo. Three kinds of specimens (original laterite stone, new laterite stone used for replacing deteriorated parts, and lime mortar used for the level adjustment) were tested in the laboratory through uniaxial compression test, etc. The test results indicated that there was no significant difference in the strength of the old and new laterite materials.
The recent global pandemic has also affected our international cooperation project severely due to the difficulty of reaching to the site yet still the request of completion of the project as scheduled. However, we are trying to adapt to this situation by trying to find a way to communicate remotely with the counterparts through effective utilization of online meeting tools and the digital data of the structure that we have created thus far.
Panel discussion at the third Mayors’ Forum
As part of the above-mentioned project commissioned by the Agency for Cultural Affairs, Tokyo National Research Institute for Cultural Properties (TNRICP) continues to support the building of an administrative network to conserve historic settlements in Nepal. On September 23rd and December 1st, 2019, workshops were organized in Kirtipur municipality with participation of engineers in charge of conservation of historic settlements from relevant municipalities. In response to their outcomes, “the third Mayors’ Forum on Conservation of Historic Settlements in Kathmandu and Kavre Valley” was held on January 5th, 2020, under the joint auspices of Kirtipur municipality and TNRICP.
The first Mayors’ Forum was held in 2018 in Panauti municipality for sharing the initiatives and issues related to preservation of historic settlements among the municipalities, followed by Lalitpur Metropolitan City in 2019.
Kirtipur municipality, whose old city area known as “a medieval settlement in Kirtipur” was listed as a UNESCO tentative list for World Heritage site, has been working on establishing its own rules for conservation. Therefore, the theme of this Forum was set as “regulatory framework for conservation of historic settlements,” and through two engineer workshops, the current issues pertaining to the systems were clarified and discussed while sharing information. As a result, the following were spotlighted as issues of administrative organizations and such systems: the existing framework for preservation of historic settlements is not effective since the policy for protection of cultural heritage of monumental nature is not linked with that for urban planning under national administration; some pioneering municipalities preserve their streetscapes under their original regulations, while others are formulating their regulations or criteria by focusing on completely different issues in municipal administration.
Accordingly, at the Forum, an officer in charge of national policy to protect cultural heritage and the one for urban planning reported about their respective conservation systems, and engineers from five municipalities delivered presentations on their legislation and issues to mutually share the tasks under national and municipal administration. Professor NISHIMURA Yukio of Kobe Design University gave a keynote speech titled “Effective Integration between Methods of Urban Planning and Preservation of Historic Settlements” while KANAI Ken, Head of the Conservation Design Section of the Institute, introduced some case studies on the Japanese system for important preservation districts of historic buildings. The Forum was attended by around 120 people, including State Minister of Urban Planning, five mayors and four deputy mayors, as well as engineers and researchers, who proactively exchanged opinions at the end.
Each municipality has several issues on conservation of historic settlements due to lack of financial and human resources, without sufficient support from the national government. Another reason for the ineffective functioning of the existing systems is insufficient basic research on historic settlements or lack of cooperative systems involving researchers and experts.
Consideration to lay the foundation to operate the network for conservation of historic settlements involving research institutions has just begun. It is anticipated that the autonomous and continuous cooperation among the persons concerned is strengthened to achieve a better environment around the historic settlements as well as its preservation.
Dismantling work with a crane truck
Head of a statue found inside the East Gate
Tokyo National Research Institute for Cultural Properties provides technical support to the Authority for the Protection and Management of Angkor and the Region of Siem Reap (APSARA) for the conservation and sustainable development of the ruins of Ta Nei Temple in Angkor, Cambodia. During the period from September 7th to November 5th, 2019, the Institute dispatched a total of six members, including outside experts, to Angkor.
In this restoration project of the East Gate of Ta Nei Temple, APSARA is responsible for implementing the dismantling work, while the Institute provides technical assistance, mainly on restoration methodologies, in addition to cooperation indocumentation and other scientific surveys .
The team began dismantling the roof of the gate by using a crane truck after praying for the safety of all persons involved in the work at the ground-breaking ceremony on September 12th. The numbered stone blocks were removed one by one from the top during which each block was measured, photographed, and assessed with its damage condition.
After dismantling the roof part, the tree roots and anthills invading the structure were removed, and the collapsed stones inside the building were taken out. Most of the collected stones, almost 70 in total,were revealed to fell down from the roof or pediment. They seemed to collapse naturally due to aging. Beneath the collapsed stones, broken head (measuring approximately 56 cm in height) of a statue, which could be identified as Lokesvara, was found leaning against the western wall of the south wing. This statue must be significant in that it is expected to shed light on the history of Ta Nei Temple, much of which is still unknown. After the find was documented with photography and 3D scanning to be described, it was moved to store at a APSARA’s facility for further study.
In cooperation with the OISHI Laboratory at the Institute of Industrial Science, the University of Tokyo, the walls and the interior of the gate were documented with a 3D laser scanner, while the Structure from Motion (SfM) technique was used to record the walls in conjunction with surveying the structure in detail. Dismantlement of the walls started on October 16th and ended safely on November 5th with the completion of the required recording.
A series of surveys following the dismantlement process disclosed the fact that the structure was deformed, partly because of the invasion of tree roots and anthills into the stone joints. Uneven subcidence of the foundation and floor surface suggests that the base structure might have some defects. The recovery of structural soundness requires the improvement of the base structure after clarifying the deterioration mechanism. Therefore, we will dispatch the staff again in December to excavate part of the foundation and investigate the ground.
Besides, we attended the meeting of the International Coordination Committee for the Safeguarding and the Development of Preah Vihear Temple (ICC-Preah Vihear) at the APSARA headquarters office on September 18th to collect the latest information. While exchanging opinions with and collecting information from international experts, we will try to find the most appropriate way to conserve the Angkor ruins in cooperation with APSARA.
Examining utilization strategies with local experts
Yuwakha village in Punakha, one of the surveyed settlements
Since 2012, Tokyo National Research Institute for Cultural Properties (TNRICP) has been conducting joint architectural research on rammed earth buildings in Bhutan with the Division for Conservation of Heritage Sites (DCHS), Department of Culture, Ministry of Home and Cultural Affairs, the Royal Government of Bhutan. From this fiscal year, TNRICP has started the Networking Core Centers for International Cooperation in the Conservation of Cultural Heritage Project, which was commissioned by the Agency for Cultural Affairs, with the objective of providing technical support and capacity building for the conservation and utilization of historic buildings in Bhutan. As a part of this project, a team of 11 experts, including TNRICP staff and outside experts, conducted on-site fieldwork from 20th to 28th August, 2019.
The field survey was jointly conducted with DCHS staff and covered traditional houses in the dzongkhags (districts) of Thimphu, Punakha, and Haa. The three main objectives were establishing a methodology for their conservation and repair, studying alternatives for their sustainable utilization, and clarifying the criteria for their evaluation as cultural heritage. Regarding the methodology for conservation and utilization, three traditional houses, which had been previously identified on the basis of features that indicated an early construction date, were selected as case studies. The potential methodologies for the seismic retrofitting of their rammed earth walls and the repair of their wooden members were studied. Furthermore, their potential use, compatible both with the owner’s demands and with the conservation of their value as cultural heritage, was examined during a discussion that involved DCHS staff, local architects, and owners. Regarding the evaluation of traditional houses as cultural heritage, comprehensive surveys were conducted in several settlements, and a potential method for the classification of traditional houses as well as a set of criteria for their designation as cultural properties was studied.
In addition, a Memorandum of Understanding referring to this project was signed at the Department of Culture, and a meeting was organized with the DCHS to discuss the results of this survey as well as the future prospects and needs of the Bhutanese counterparts.
In the future, we expect to continue cooperating with Bhutanese experts through on-site surveys and workshops to establish a methodology for the conservation and utilization of historic buildings suited to the Bhutanese reality.
Classroom lecture at Tokyo National Research Institute for Cultural Properties
Tour of restoration conditions at the Shinmachi-Furumachi District in Kumamoto City
A civil war broke out in Syria eight years ago in March 2011, and it seems there is no end in sight. Apart from the human cost of war, the much precious cultural heritage was also lost.
The Japanese government and the United Nations Development Programme (UNDP) began providing cultural heritage aid to Syria in 2017. From February 2018, the Archaeological Institute of Kashihara, Nara Prefecture, in association with academic organizations such as the University of Tsukuba, Teikyo University, Waseda University, Chubu University, and the Ancient Orient Museum, has been accepting Syrian specialists and providing them training in the fields of archeology and restoration. Tokyo National Research Institute for Cultural Properties is also participating in this project.
Following training seminars on conservation and restoration of paper cultural properties held in May 2018, this year, two Syrian specialists were invited to undergo training in “Research Planning Methods to Restore Historical Cities and Buildings” conducted from July 24th to August 6th.
Many historical cities such as the ancient city of Aleppo were engulfed in war, and many historical buildings were devastated. In the first half of this year’s training, seven specialists gave classroom lectures on surveying damage to historical buildings and making emergency repairs, structural safety diagnosis method, documentation and database creation method, restoration plan creation method, and restoration and preservation system creation method. For the practical aspect that comprised the second half of the training, participants inspected the restoration status of historical buildings and townscapes devastated by the 2016 Kumamoto Earthquakes, including Kumamoto Castle, the Shinmachi-Furumachi District, Kumamoto University, and the Eto-yashiki (Eto estate), which is registered as an important cultural property.
The participants also heard stories told by the people in charge. They visited Preservation Districts for Groups of Traditional Buildings in Kyoto and Nara and saw examples of repairs and applications of historical Japanese buildings.
We would once again like to thank the specialists, related organizations, and personnel-in-charge for their support.
Tokyo National Research Institute for Cultural Properties plans to continue support activities for Syrian cultural heritage in the future.
Participants at the expert meeting
Case study of the utilization of traditional houses (Fukusumi)
Tokyo National Research Institute for Cultural Properties (TNRICP) provides the Royal Government of Bhutan with technical support and human resource development for heritage conservation and sustainable utilization of historic buildings, including traditional houses, under the scheme of International Cooperation Project for Cultural Heritage by the Agency for Cultural Affairs in Fiscal Year 2019. TNRICP invited two staff members of the Division for Conservation of Heritage Sites (DCHS) from June 23rd to 28th to Japan to hold the first expert meeting and a case study tour in western Japan.
At the meeting, Mr. Yeshi Samdrup of DCHS presented a report on the progress of the development of the legal system concerning cultural heritage, and Mr. Pema Wangchuk of DCHS made a presentation on the prospects for the protection of traditional houses and settlements. Participants shared the recent challenges and dilemmas concerning the protection of cultural heritage in Bhutan through their presentations and the subsequent discussion. The subject of the field survey scheduled for this August was also discussed, and the specific survey method has been almost fixed.
In the case study tour, we visited the Ozaki family residence (Yurihama, Tottori), which is undergoing conservation work, and the Open Air Museum of Old Farm Houses (Toyonaka, Osaka) where typical traditional houses from all over Japan have been collected to study basic concepts of the protection of traditional houses as cultural property in Japan. We also visited historic towns and villages where historic townscapes have been rehabilitated, namely Shikano (Tottori), Oyacho-Osugi, Sasayama, Fukusumi (all above, Hyogo), and Miyamacho-Kita (Kyoto), to spread knowledge about community involvement and heritage tourism where traditional houses can be utilized as accommodation. The invitees were particularly interested in the nongovernmental management of cultural heritage that should be treated under the new law in Bhutan, and there was a lively exchange of views and opinions with the local presenters at each site.
We would like to extend our deep appreciation to all the people involved in the tour for providing this opportunity.
Site visit by members of the Ad Hoc Experts Group of ICC
Removal of scattered stone blocks with the mobile crane
Tokyo National Research Institute for Cultural Properties (TNRICP) provides technical support to the Authority for the Protection and Management of Angkor and the Region of Siem Reap (APSARA) for the conservation and sustainable development of the ruins of Ta Nei Temple in Angkor, Cambodia. TNRICP dispatched a total of five staff members to Cambodia from May 19th to June 29th, 2019 in order to carry out preparatory work before the examination of the restoration plan for the East Gate by the International Coordinating Committee (ICC) and the start of the restoration work.
APSARA and TNRICP submitted the plan for dismantling the structures to the ICC technical session, which was held on June 11th and 12th. As a result of careful deliberation including a site visit by the three members of the Ad Hoc Experts Group, the plan was adopted as proposed with minor corrections. As necessary preparation for the restoration work, we cleaned out and organized scattered stone blocks around the East Gate, and also carried out excavations for drainage route examination.
We recorded and numbered scattered stone blocks and moved them out of the way of the restoration work. Thanks to the mobile crane provided by Nara National Research Institute for Cultural Properties (NNRICP), which is restoring the Western Prasat Top Site, we were able to move the stone blocks in a short time.
During the excavation we tried to clarify the difference in the old ground surface level between the northeast end of the Cruciform Terrace and around the East Gate, in order to examine the natural drainage route from the East Gate area. The elevation around the East Gate is lower than the surrounding area, and it is feared that rainwater may stagnate there, which is why we plan to set up a drainage channel to the North Moat for future maintenance. In addition, we found laterite stone paving which is presumed to be a part of the approach that connects the Cruciform Terrace and the East Gate. It is expected that further excavations will provide clearer information.
The 2nd Mayors’ Forum
As part of the above-mentioned project commissioned by the Agency for Cultural Affairs, Tokyo National Research Institute for Cultural Properties (TNRICP) continues to support the building of an administrative network to preserve historic settlements in Nepal. The “2nd Mayors’ Forum on Conservation of Historic Settlements in Kathmandu and Kavre Valley” was held in Lalitpur Metropolitan City on March 12th, 2019, under the joint auspices of Lalitpur municipality and TNRICP, which dispatched eight researchers.
At the 1st Mayors’ Forum held in Panauti in 2017, the state of preserving historic settlements and related issues were shared and discussed. The theme of the second forum was “conservation of tangible and intangible cultural heritage in historic settlements.” Presentations were given by experts from Nepal and Japan and a discussion was held with the attendees. On the day in question, around 80 people, including 11 mayors, 8 deputy mayors, and several government-affiliated engineers, participated from 14municipalities.
From the Nepal side, presentations were given on festivals and intangible cultural heritage such as festivals and craftworks in four municipalities and initiatives to pass them on to future generations as well as historic settlement surveys and conservation initiatives after the 2015 Gorkha Earthquake. From the Japan side, Tomoko MORI, Associate Professor at Sapporo City University, presented the survey results from Khokana village, while Hiromichi KUBOTA, Head of the Intangible Folk Cultural Properties Section of TNRICP, presented the survey results of intangible cultural heritage in Khokana and the state of conserving intangible cultural heritage in Japan.
Both countries have common issues in conserving local cultural heritage, such as lack of personnel and funding. In Nepal, as changes in traditional local communities accelerate, a sustainable framework for conserving cultural heritage in local communities and appropriate support from the local government under the leadership of mayors are essential.
We will continue to provide technical assistance while sharing information and deepening dialogue between the two countries.
Investigating a sample from target building
Sample with the finishing layer from each period carved out in tiers
As part of this project commissioned by the Agency for Cultural Affairs of the Japanese Government, a compositional analysis of the finishing layer of a group of buildings adjacent to Aganchen Temple at Hanumandhoka Palace, Kathmandu, was performed using an X-ray fluorescence spectrometer, etc., from February 22nd to 28th, 2019, with permission from the Department of Archaeology, Government of Nepal.
On-site surveys conducted so far have revealed that a number of extensions and structural alterations had been made to these buildings. In particular, the wall finish recoating history and the remaining finishing layers at hidden areas of retrofitted support members are important clue in learning about the changes to the buildings. Study on the specifications and coloring of each recoated layer has continued.
This time, the composing materials of the finishing layers were identified in order to understand how specifications changed according to the times, and a scientific analysis was performed using an X-ray fluorescence spectrometer and a Raman spectrometry system to examine the history of extensions and structural alterations.
A fragment of the finishing layers investigated comprised a maximum of 10 different sets of layers. Surface and undercoat layers from each period were carved out in tiers and analyzed.
Red iron oxide and minute amounts of gold were confirmed in red-colored areas of the old mural painting layer, and a spectrum quite similar to lapis lazuli was derived from the sky-blue finishing layer recoated in later years. While a detailed analysis of the derived data has yet to be performed, it can be inferred from the use of such precious materials that these buildings had continued to be used as important ritual or residential spaces for a royal family since their initial construction in the 17th century.
In the process of surveying the remains, a mural painting was discovered behind the extended wall section, and it is possible that this mural dates back to a period just after the original construction of the building. Further surveys, including through scientific methods, such as the one used this time, and studies of appropriate preservation measures are still needed.
Hereafter, we will continue to elucidate the history concealed in the buildings themselves, and while preserving such significant material evidence, we will consider how to go about restoring these buildings in association with the Nepalese counterpart.