Which of the following is a feature of the DOT 412 cargo tank?

• A. 12 evenly spaced ribs
• B. Single work platform
• C. Tank will fit between the wheels
• D. Rear painted white

Answer: (A)

Recognizing the design that identifies DOT 412 tanks is key here. DOT 412 cargo tanks are built with external stiffening ribs along the length of the shell to strengthen the tank and control bending and buckling under load. Having a dozen evenly spaced ribs provides uniform rigidity, helping the shell handle internal liquid pressure and dynamic stresses during transport. This feature is a defining characteristic that inspectors and operators use to recognize this class of tanker.

The presence of twelve evenly spaced ribs is the best answer because it directly reflects this structural design aspect. Other options describe attributes that aren’t defining features of the DOT 412 design—such as a work platform, fit between the wheels, or the tank’s color—which can vary and aren’t the distinguishing structural identifier for this tank type.