Yamada Shokai Holding Co.
Liberaware Inc.
Ninna-ji Temple, head temple of the Omuro school of Shingon Buddhism

(Head Office: Nagoya City, Aichi Prefecture; Representative: Toyohisa Yamada), in cooperation with Liberaware Corporation, conducted a drone inspection of the underfloor and ceiling at Ninna-ji Temple, the head temple of the Omuroha sect of the Shingon Sect, a World Heritage Site, on December 4, 2024.

As a country that is prone to natural disasters, Japan needs to be resilient in the face of earthquakes and other disasters. In particular, for buildings such as temples, which are required to "stay in use for a long time," regular inspections and maintenance are essential, including under floors and ceilings.

At Ninna-ji Temple, which has cooperated in the demonstration of under-floor inspections using a small drone, government subsidies are being used for temple inspections and repairs, with a design engineer for each building checking the site and formulating specifications and rough estimates for repair plans, and a qualified palace carpentry company checking the site while repairs are being made. A qualified shrine carpentry company carries out the repairs while checking the site. We conducted a drone inspection in the presence of the shrine carpenter who is actually repairing the Ninna-ji Hakushoin and verified the feasibility of such an inspection.

Summary of the Demonstration

Objective: To verify feasibility of underfloor/attic inspection by small drone
Demonstration site: Under the floor of the White Drawing Room of Ninna-ji Temple
Estimated floor space: 196 m2 (building area of Ninna-ji Temple's Shiroshoin)
Aircraft used: Liberaware IBIS2
Inspection points: Under the floor and ceiling
Inspection time required: 1 hour each under the floor and ceiling

[Demonstration Results Key Points

• Small drone inspections can be used for both specification by designers and inspection/repair work by palace carpenters.
• In underfloor inspections, it can increase the efficiency of pre-confirmation work when formulating specifications.
• In addition to preliminary attic inspections, the system can be used to improve efficiency in checking, recording, and measuring the condition of the attic.
• In attic inspections, the initial confirmation work, which previously took four people three days, can be reduced to about half a day through the use of drones.

Comments from Fat companies
World Heritage Site Ninna-ji Temple, head temple of the Omuro school of Shingon Buddhism
In the past, Ninna-ji Temple has created the "Omuro Digital Museum Online," a special online website that allows visitors to view the cultural assets of Ninna-ji Temple, and has also been involved in a project to use the Shorin-an historical building on the temple grounds as a lodging facility. We are working to transmit new added value through initiatives that respond to the needs of the times. The maintenance and management of temples that have been carefully protected for centuries in each region has been built up day by day with the cooperation of various stakeholders of that era, seeking effective methods. We believe that the streamlining of temple inspection work through the use of small drones is an initiative that will not only maintain existing cultural properties, but will also lead to the creation of new cultural properties and the passing on of skills.

Liberaware Inc.
The IBIS2, a small drone developed and provided by Liberaware, has been used mainly for inspecting "cramped, dark, and dangerous" infrastructures and facilities, but in the course of this project, we have found that it is also effective in inspecting historical buildings and surveying the current conditions during renovation work, in terms of "avoiding human intrusion into dangerous sites" and "significantly reducing the time required for inspections and surveys. In particular, the system has proven to be effective in the frequent inspection of historical buildings and in the surveying of existing conditions during renovation work. In particular, with regard to renovation work, there is often no past data because it is not done frequently, and in many cases, the information necessary for technological succession is considered insufficient. We believe that the continuous acquisition of video and point cloud data that can be easily shared among technicians through the use of small drones will be of great value in efficiently maintaining important historical cultural properties.

Yamada Shokai Holding Co.
For 120 years since its establishment, Yamada Shokai has been working to improve the resilience of towns and buildings through gas construction. Through this demonstration with Liberaware, we were able to confirm that the system can improve both workability and safety compared to conventional inspection methods. By preserving cultural assets that have been cherished since ancient times as digital data, we felt the possibility of improving resilience against disasters and communicating their value beyond time and space.

＜Inquiries regarding this matter
Yamada Shokai Holding Corporation (Attn: Toshiyuki Kimura)
Phone: 052-871-9811 Email: yamada-hd@ymax.co.jp