Blocks Review

Summary

Many kinds of blocks are used in sailing. Acting as a pulley or a set of pulleys, boat blocks can be used to change the direction of a line or to supply mechanical advantage when you need to move something. Having more mechanical advantage means that you expend less effort to move heavier objects. The outer parts of a block are called the cheeks; the inner parts are the sheaves. A rope or cable is threaded through the sheaves to form a block and tackle. Blocks may be installed at fixed points or may be movable. Ratcheting blocks are set for the line to move in only one direction. For temporary rigging, snatch blocks may be useful, especially when wind conditions require changing the headsail fairlead blocks. Snatch blocks do not require threading of the line, but open up so that the line can be inserted quickly. They also usually have a snap shackle so that they can be quickly placed almost anywhere on the boat. Snatch blocks are not recommended for permanent use or for use as turning blocks.

Deck organizers can also help sailors with halyards and control lines that need quick adjustments. These organizers make the best use of your space on the deck and allow you to operate the lines with more safety.

When replacing blocks, be aware of the safe working load of your parts and bases. Look at the load total and the total size of your assembly, as well as the friction that will be encountered. Higher quality materials in blocks will last longer and be less prone to failure. Routine maintenance is also important in keeping blocks in working order. Determine the correct lubrication for your blocks and inspect them regularly, looking for cracks or stresses from friction. Many types of blocks need a heavy lubricant such as Lanocote for the best functioning, but other brands recommend washing with water and a light lubricant.

Pros

• Blocks provide mechanical advantage in lifting loads.
• Blocks enable changing the direction of lines.
• Deck organizers make efficient use of deck space.

Cons

• Blocks require regular inspection and maintenance for proper functioning.

Featured Manufacturers

Navtec, Harken, Ronstan, and Wichard

Conclusion

Blocks and block and tackle assemblies create pulley systems for the many needs of boaters and sailors. Correctly installed blocks allow heavy loads to be moved much more easily and permit the many adjustments of lines necessary in sailing. Marine suppliers have many varieties of blocks and parts for different types of loads. Deck organizers can be helpful in keeping up with halyards and control lines. Snatch blocks are recommended for temporary assemblies that need to be put together quickly. Proper maintenance and lubrication of blocks is necessary to ensure the efficient functioning of these moving parts.