The most common size cribbing is:

The most common size for cribbing is often recognized as 4" X 4" X 18". This size is favored in vehicle rescue operations due to its versatility and strength. Cribbing is used to stabilize vehicles or other structures safely during rescue operations, allowing for safe handling and access to victims. The dimensions of 4" by 4" provide enough surface area to distribute weight effectively and ensure stability, while the length of 18 inches allows for various configurations and stacking to suit the needs of specific rescue scenarios.

Furthermore, larger cribbing, like the 4" X 4" X 18", can help in creating a robust support system, which is necessary for safely lifting or stabilizing a vehicle without compromising the safety of rescue personnel or victims. Other sizes mentioned may not provide the same stability or may not be as commonly used in practice for this specific purpose.