CDL Tanker Endorsement Practice Exam

What is one consequence of filling a tank completely?

1. It may cause spillage during transit

2. It ensures maximum cargo capacity

3. It could lead to a lighter load

4. It minimizes costs

The correct answer is: It may cause spillage during transit

Filling a tank completely can indeed lead to spillage during transit, especially when the vehicle is in motion and subjected to various forces. When a tank is filled to the brim, there isn’t enough space for the liquid to expand due to temperature changes or movement, which can result in overfilling. If these factors cause liquid to slosh around, it can spill out of the tank, creating safety hazards, environmental concerns, and potential legal repercussions. Proper management of tank loads typically requires leaving some space in the tank—often referred to as "ullage"—to account for these dynamics and to prevent spills. While ensuring maximum cargo capacity might seem advantageous, it does not account for the safe transportation practices that are essential for tanker operations. A full tank does not guarantee safety and could lead to potentially disastrous situations during transport.