We have previously reported on the benefits of composite backstays: to reduce weight aloft and increase performance. An effective control system to finely tune backstay load is equally important, particularly for a race yacht. In this blog we look at 3 popular configurations for backstay purchase systems using block and tackle.
Image Credits: Ronstan
Well known around the world, Ronstan is a great choice for blocks and sheaves for a variety of sailors. They have developed a number of ranges from the basic Utility range to the advanced precision Orbit range.
When it comes to the Ino-block range, the manufacturer firmly believes that simplicity is key, and we tend to agree with them.
Based on the same concept as the innovative Ino-block, the Ino-ending block has been stripped of many of the shortcomings of a traditional block. No central metal axle that could warp or crack, no pins or shackles that could shatter, no ball bearings or other complex moving parts. Instead the block has been reduced to three simple pieces.
Deck blocks are evolving. Bearings are constantly improving, as manufacturers endeavour to minimize friction in different load cases.
Types of bearings
Apart from number of sheaves, blocks can also be categorised by their bearings.
• Plain bearings: Although the name itself sounds quite vague, these are smooth, solid surfaces that
move across each other. The sheave rotates across the central hub.
