|■Tokyo National Research
Institute for Cultural Properties
|■Center for Conservation
|■Department of Art Research,
Archives and Information Systems
|■Japan Center for
International Cooperation in Conservation
|■Department of Intangible
“Humidity-controlled high-temperature treatment for the bell tower of Chuzen-ji Temple in Nikko (branch temple of Rinno-ji Temple) and on-site inspection”
On September 10th, 2018, we visited Chuzen-ji Temple to inspect the “Humidity-controlled warm air treatment ” for its bell tower. This treatment method aims to expel noxious insects harming pillars and beams of wooden structures under a high temperature (around 60°C). Usually, as the temperature increases, wooden building materials crack or strain. However, it is possible to increase the temperature inside the wood almost without affecting its physical property, since the temperature rises while the humidity in the treated space is controlled with the wood water content maintained at a certain level. The conventional yet sole insecticidal method for historical wooden structures is fumigation treatment, where a structure sealed with covering is filled with vaporized pesticide to exterminate noxious insects inside the wood. However, vaporized gas also affects human health, thus, requiring safety measures against greater risks. Accordingly, it was hard to implement such large-scale treatment for wooden structures continually. This Humidity-controlled warm air treatment is expected as a new approach to overcome such a challenge.
So far, a research team comprising the Association for the Preservation of the Nikko World Heritage Site Shrines and Temples, Kyoto University, Kyushu National Museum, Total System Laboratory Co., the Japanese Association for Conservation of Architectural Monuments, National Museum of Ethnology, Natural History Museum and Institute, Chiba, and Tokyo National Research Institute for Cultural Properties has been proceeding with the studies from basic research for application to old wooden buildings to establishment of application technique. In the basic research, we verified the humidity distribution in the treated space during the test with a chamber, as well as the temperature distribution inside the wood, measured surface strain, and effects on wooden materials. Then, following the treatment testing with a model structure by using a pilot unit manufactured to control the temperature and humidity of actual structures, we finally realized on-site treatment testing of a historical wooden structure for the second time in Japan after Aizendo Hall of Chuzen-ji Temple. We would like to move ahead with this research toward the dissemination as one of new insecticidal methods while organizing these two treatment test results obtained from two buildings of Chuzen-ji Temple.
The symposium in session
On-site survey: Steam hammer Taipei Factory No. 141 still remains at the smithery in the vehicle factory of Taipei railway workshop (manufactured by Toyo Iron Works and purchased in 1934).
The Modern Cultural Heritage Section has been interacting with Taiwanese officials and researchers working on cultural properties since FY 2017 so as to share mutual experiences and issues on conservation and utilization of modern cultural heritage for their smooth resolution through research.
As part of this activity, we participated in the “International Symposium on the Conservation of Modernization Heritage and Its Promotional Planning” held under the auspices of the Bureau of Cultural Heritage, the Ministry of Culture and Chung Yuan Christian University in Taiwan on August 17th, 2018. At the symposium, Japanese experts representing the industrial heritage, railway and machinery areas delivered lectures. Mr. Kitagawa, the Head of the Modern Cultural Heritage Section at Tokyo National Research Institute for Cultural Properties, lectured on the administration of cultural properties related to modernization heritage. The symposium attracted a large Taiwanese audience, including administrative officials, owners of cultural properties, university researchers, and citizen groups, resulting in engaging discussions ranging from the principles of conservation and utilization of modernization heritage to their approaches.
In conjunction with the symposium, we discussed with Taiwanese researchers how hydraulic structures, factories, and railway facilities constructed during the period of Japanese rule have been conserved and utilized, along with various approaches and issues. Among them was a very interesting case in which a motorcycle manufacturer who had developed an electric-assist railbike made use of the dead track of a now-defunct railway. The railway is now protected as a cultural property for the operation of the facility.
We also visited Director-general Gwo-Long Shy and other officials at the Bureau of Cultural Heritage, the Ministry of Culture in Taichung. There, we exchanged ideas on Japanese and Taiwanese histories, and on concepts concerning systems for the protection of cultural properties associated with modernization heritage, as well as their conservation and utilization.
Jet engine components displayed in the venue
The Institute of Asian Cultural Studies and the Peace Research Institute of International Christian University, and Tokyo National Research Institute for Cultural Properties held a symposium titled “Towards a History of “HERE”: Learning from the Phantom Jet Engine” at the University on June 2nd, 2018. This symposium focused on looking back at the history of International Christian University (hereafter called “ICU”) founded on the premises of the research institute of the Nakajima Aircraft Company, which developed three jet engine components discovered on the campus in 2015, while widely sharing their values as cultural properties.
For the first half of the symposium, Mr. Masahisa TAKAYANAGI, a teacher at ICU High School, talked about how the components were discovered, and their significance. Then, Mr. Hiroyuki NAGASHIMA, former visiting researcher at this Institute, introduced the outcomes of the survey on cultural properties conducted jointly by Tokyo National Research Institute for Cultural Properties and the Japan Aeronautic Association in 2017; and Mr. Shigeyoshi KANDA, a visiting researcher at this Institute, presented reference information contributing to their publication and utilization in the future. For the last half of the symposium, following the screening of a video work produced by students, Mr. Hikaru OKUIZUMI, a writer, Dr. Yoko KATO, a professor at the University of Tokyo, and Dr. Masakatsu OKADO, a professor at Yokohama National University, gave their perspectives from their own points of view in a bid to evoke speculation about the jet engines, and the histories of the Tama area and World War II. At the end of the symposium, a comprehensive discussion was created based on questions from the audience.
ICU is expected to continually consider conservation and utilization approaches that are unique to education and research institutions by clarifying the histories of the university and the surrounding area and using cultural properties to convey their values to many people while reviewing the issues presented by them.