Rhadamanthus was a fast, fragile step toward Renown

What was the Rhadamanthus-class battlecruiser?

It was a lightly protected, high-speed Fisher paper study whose ideas helped feed into the eventual Renown design.

Rhadamanthus was one of Fisher's theoretical design studies and contributed to the ideas that became Renown. It proposed still higher speed at the expense of armour. The panel describes that protection as a paper jaw, making the vulnerability part of the design assessment. The study also predates Courageous, Glorious, and Furious and helps explain Fisher's later enthusiasm for their lightly protected designs.