This design used a split backstay and a combination of blocks that, when tensioned, pinched the two sides of the split backstay together. By doing so, the backstay was tightened.

It is an inexpensive method of creating an adjustable backstay, but not the most effective one. The farther down the backstay is pinched together, the less mechanical advantage you have. Finally, just when you need the most, you have the least. A more effective system is the "cascade" design pictured below. The cascade design provides a constant mechanical advantage throughout its range of travel.