What are snatch blocks?

Snatch blocks are specifically designed pulleys that are essential for rigging and lifting applications. They serve two primary functions: they help reduce the tension on a winch line, allowing for smoother operation, and they can change the direction of the pulling force. By utilizing a snatch block, the effective pulling capacity of the winch can be increased, and loads can be maneuvered more easily around obstacles or in tight spaces. This capability makes snatch blocks indispensable in various scenarios, such as towing, recovery operations, or any situation where heavy loads need to be moved efficiently.

The other options do not accurately describe snatch blocks. Instead of referring to a physical block for securing tires, which is unrelated to the lifting and rigging context, or listing a vague term like '4x4' that refers more to vehicle types than rigging equipment, the correct understanding lies in the functionality and application of pulleys. Additionally, scotch blocks refer to a type of pulley used in sailing and have different characteristics and uses compared to snatch blocks, highlighting the distinction between the terms.