also: なまずごう
noun
earthquake simulator
A device or vehicle that simulates earthquake shaking, named after the catfish (ナマズ) which is associated with earthquakes in Japanese folklore.
防災訓練でナマズ号に乗って震度7の揺れを体験した。
During the disaster drill, I rode the earthquake simulator and experienced shaking of intensity 7.
From ナマズ (catfish) + 号 (suffix for named vehicles/devices). The catfish is a traditional symbol of earthquakes in Japan, hence the name for an earthquake simulator.