A 37-year-old man hurt his right knee on a roller coaster when part of a plastic cover came off the ride at the Fujikyu Highland amusement park near Mount Fuji in Fujiyoshida, Yamanashi Prefecture, the park's operator said Tuesday.
The man was in the last car of the four-car Dodonpa ride Monday when the cover, which was on the connecting part between the second and third cars, came off and slid backward, hitting his knee, the operator said.
The sit-down roller coaster has four connected cars, with two seats in each car. The plastic cover, which is 60 cm tall and 30 cm wide, weighs 3 kg, the operator said.
The man suffered a minor injury probably because the accident occurred when the coaster was slowing down as the ride was coming to an end, it said. During the course of the ride each coaster goes as fast as 172 kph.
The cover, which was secured by four bolts, appears to have come off due to cracks made from vibrations, the operator said. Staff found no problems in the coaster when they inspected it Monday before opening the park, it said.
On May 5, Yoshino Kogawara, 19, was killed and 19 other people were injured when a stand-up roller coaster derailed and hit an emergency walkway handrail alongside the course at the Expoland amusement park in Suita, Osaka Prefecture.
Investigators found that the axle that locks the left unit of five wheels on the second car was broken. Kogawara was in the second car. When the axle broke, the wheel unit dislodged, allowing the car to tilt and hit the handrail.
Since that accident, amusement parks nationwide have been conducting checks on their roller coasters.