CDL Tanker Endorsement Practice Exam

What does a baffle in a liquid cargo tank primarily do?

1. Prevent motion from front to back

2. Eliminate surge completely

3. Prevent movement of surge from side to side

4. Increase cargo capacity

The correct answer is: Prevent movement of surge from side to side

A baffle in a liquid cargo tank primarily functions to prevent the movement of surge from side to side. When liquid is transported in a tank, it can shift and create sloshing movements, particularly during acceleration, deceleration, or turning. Baffles are installed as vertical barriers within the tank, which help to mitigate this side-to-side motion by breaking up the flow of liquid. This design feature is crucial for maintaining stability and control of the vehicle while driving, as excessive sideways movement can lead to difficulty in steering and increase the risk of tipping over. While baffles can help reduce the surge effects, they do not eliminate surge completely, nor do they prevent forward and backward movement of liquid. The design and purpose of a baffle is primarily focused on controlling lateral motion, not increasing cargo capacity. Thus, understanding the role of baffles is essential for safe transport of liquid loads in tanker vehicles.