What term refers to a car designed to hold containers for transport, allowing double stacking?

The term that refers to a car designed specifically to hold containers for transport, allowing for double stacking, is indeed double stack car. This type of rail car is engineered with a structure that accommodates two layers of containers on top of each other, maximizing the efficiency of cargo transportation by utilizing vertical space.

Double stack cars are typically equipped with features like well decks that secure the containers in place and are designed to support the weight and dimensions of the stacked containers. This innovation plays a significant role in enhancing the capacity of rail transport, enabling transportation networks to move larger volumes of goods more efficiently.

Container cars, while designed to carry containers, may not specifically endorse the double stacking capability. Flatcars are versatile but are not exclusively tailored for containers stacked in this manner, and boxcars are enclosed cars usually used for carrying bulk goods and do not stack containers. Thus, double stack car is the precise term that captures the functionality and design intended for this method of container transport.