What is a defining feature of the MC 338 cryogenic liquid tank car?

The defining feature of the MC 338 cryogenic liquid tank car is that it includes insulation for low temperature operation. This type of tank car is specifically designed to transport cryogenic liquids, which are substances that exist in a liquid state at very low temperatures, such as liquefied natural gas or liquid oxygen. The insulation is vital as it minimizes heat transfer, keeping the cryogenic liquids at the necessary low temperatures during transport, thus preventing evaporation and maintaining the integrity of the cargo.

Additionally, the construction of the MC 338 is tailored to handle these lower temperatures safely, which distinguishes it from other types of tank cars that may be designed for different substances or conditions. This insulation is crucial in maintaining the safety and efficiency of transporting cryogenic materials, making it a key characteristic of the MC 338 cryogenic liquid tank car.