noun
flatcar
A railway freight car with a flat, open deck and no sides or roof, used for carrying containers, vehicles, or heavy loads.
工場から出荷されたトラックは、平台型貨車で運ばれた。
The trucks shipped from the factory were transported on flatcars.
この駅では、平台型貨車にコンテナを積み込む作業が見られる。
At this station, you can see the work of loading containers onto flatcars.
Compound of 平台 (flat platform) + 型 (type) + 貨車 (freight car). The exact historical derivation is uncertain, but the term transparently describes a flat-deck freight car.