Investigation of Modern Cultural Heritage in Minamikyushu City
Tokyo National Research Institute for Cultural Properties (TOBUNKEN) worked with Minamikyushu City for “memorandum concerning the conservation and restoration of cultural properties designated by Minamiyusyu City”, and recently started joint research in July, 2022.
（https://www.tobunken.go.jp/materials/ekatudo/996061.html）
The following surveys and investigation were conducted in Minamikyushu City in February, 2023.
Investigation and advice on preservation and restoration of the former Japanese Army Type 4 fighter “Hayate”
The “Hayate” (designated cultural property of Minamikyushu City), which is stored and exhibited at the Chiran Peace Museum, was captured by the US military in the Philippines during the Asia-Pacific War and is the only surviving aircraft.
After a test flight by the US military, it was sold and passed through multiple owners before it was returned to Japan in 1973. When the town of Chiran (now Minamikyusyu City) was established in 1995, the aircraft was transported there and has been on display at the Chiran Peace Museum since 1997.
Since 2017, Minamikyushu City has been conducting a conservation survey, and TOBUNKEN has participated in the survey from 2018. Our findings suggest that overall, the fuselage is in good condition, but some parts have worn out or been replaced because of the post-war test and demonstration flights. We will continue to check the status of the remaining original parts and consider the restoration policies. In this investigation, we mainly targeted the engine, checked the original parts, and the condition inside the engine and oil tank, among other things. Some parts removed from the aircraft were entrusted to TOBUNKEN for cleaning and component analyses.
The research was conducted in the exhibition room. Since the exhibition room was not closed during the research period; visitors were able to observe it at that time. Additionally, a report on the state of preservation was published in March, 2022.
Air quality investigation of exhibition rooms and storage in the Chiran Peace Museum
In this study, we conducted an air quality investigation (inspection of organic acids, aldehydes, and volatile organic compounds [VOC]) in the exhibition room and storage room along with a survey of ” Hayate.” In the future, we plan to consider a more stable exhibition and storage environment based on the results of this investigation.
Records of the current state of concrete structures during the Asia-Pacific War in Minamikyushu City
Minamikyushu City has there are cultural assets related to numerous wars and the former Chiran Airfield. They have remained in the city since the Asia-Pacific War period. Many of them are concrete structures, but nearly 80 years have passed since the end of the war, and they are deteriorating and falling debris. In this study, we recorded the current situation by obtaining actual measurements and photogrammetry (three-dimensional models were created from multiple photographs) of the former Chiran Airfield water tower (a city-designated cultural property) and two pillboxes (defensive positions) of the former Aoto Airfield as concrete structures in the city during the relevant period. In the future, we will analyze the progress of deterioration based on regular records and consider measuring concrete strength.