Wind tunnels offer an early way to identify island turbulence

Early Hermes and Eagle concepts considered twin island structures alongside a full-length flight deck. Trials on Furious later demonstrated how severely superstructure could disturb airflow over the deck, but wind-tunnel work had already identified part of the problem. A carrier ordered before the war might still have received twin islands, although that outcome is judged unlikely if further testing exposed the interference. Wind tunnels were established tools by this period. Manchester had undertaken relevant work in the late nineteenth century, the Wright brothers used a wind tunnel in 1901, and Gustave Eiffel built an open-return tunnel in France in 1909. A navy already conducting extensive hull experiments could reasonably commission more aerodynamic testing for carrier designs. That provides a plausible route to similar design conclusions without first experiencing the landing difficulties aboard Furious.