Japan Railway Firm Tests Out Drones to Clean High-Rise Windows

The Yomiuri Shimbun

20:00 JST, March 29, 2026

Drones cleaned the windows of a high-rise hotel in Hiroshima recently as part of a test that explored how well the technology can be used.

Japan Railway West Trading Co., a JR West Group company, tested out the drones on March 23 at Hotel Granvia Hiroshima South Gate in the city’s Minami Ward.

The company, based in Suita, Osaka Prefecture, is exploring the possibility of employing drones to address a decline in the working population and ensure the safety of window cleaners.

Cleaning bird droppings

TRIPLE7, a company based in Shibuya Ward, Tokyo, which works in various business including operating a drone school, provided the equipment and handled the drone operation.

The main drone used was 98 centimeters long, 76 centimeters wide and 48 centimeters tall and came equipped with a high-pressure nozzle. It took off from the 8th floor of the hotel and sprayed water at bird droppings on the windows of a guest room on the 15th floor, approximately 70 meters above ground.

It continued to remove dirt by spraying water on the windows for about 20 minutes. The drone also cleaned guest room windows on the 21st floor, approximately 90 meters high.

The hotel opened in March last year as part of a multiple-use complex developed directly above JR Hiroshima Station. Guest rooms are located on the 9th to 21st floors.

This latest test checked the quality of cleaning done by a drone and its impact on hotel guests.

The drone operators also simultaneously flew a smaller drone equipped with a camera to closely confirm the location of dirt on the windows and the results of the cleaning.

Work cut down from 5 days

The test was made possible following a request made by the hotel.

“When bird droppings stick to the windows, they spoil the view from the guest room, making it no longer usable,” said Koichi Nagata, an assistant manager of the hotel. “We were troubled by the fact that the room would remain unavailable until the cleaning was done.”

According to the hotel, high-rise window cleaning had been done once before. At that time, a pair of workers boarded a window-cleaning gondola attached to the rooftop. The window cleaning work took a total of five days for the two.

Meanwhile, Japan Railway West Trading created an in-house drone team in 2024 and has been exploring ways to utilize drones for business purposes.

Last December, the company tried out drones to deliver supplies along the Hokuriku Shinkansen line in Fukui Prefecture in preparation for such situations where delivering goods via people or vehicles would be difficult due to such circumstances as disasters.

Challenges remain for practical use

Makoto Kitayama, a team leader for the test at the hotel, said: “High-rise cleaning work on buildings in urban areas, for instance, presents many challenges in terms of ensuring workers’ safety and costs. We think this could be an area where we can put the drone’s technology to good use.”

During the test, the drones were able to wash away conspicuous lumps of dirt from the windows. But stains remained slightly in some areas, highlighting challenges that must be dealt with before the drones are put to practical use.

“We were able to fly the drones safely. But there is still much we have to learn when it comes to removing the dirt,” said Takuya Ishihara, a managing director of Japan Railway West Trading.