Thistlebase
Cunningham Rings: What They Are and Why
Comprehensive technical article explaining Cunningham Rings (also called Coker Rings), their purpose, advantages, disadvantages, and how they function in adjusting mainsail tension on Thistle sailboats.
View original on Google Drive · page 17
The scanned issue opens in Google Drive; turn to page 17.
This is a summary. The full article text is © the Thistle Class Association — read the original scan via the link above.