When are chock blocks for a cargo tank vehicle required to be used?

Chock blocks are essential for cargo tank vehicles to ensure safety and stability during various operations. Their use is mandated whenever a cargo tank is loaded, unloaded, or parked. This requirement is primarily to prevent the tank from rolling or shifting unexpectedly, which could lead to dangerous spills or accidents associated with liquefied petroleum gas (LPG) transportation.

In the context of loading, chock blocks provide stability while the tank is being filled or emptied, minimizing the risk of movement. When parked, especially in areas where there might be an inclination, applying chock blocks further secures the vehicle against unintended rolling. Thus, it's crucial that they are utilized at all times when the vehicle is not in motion to enhance safety during these critical operations.