The purpose-built list shows a fleet investing at speed even as the design category was about to be overtaken. Only about 21 years separate the 1839 launch of the last sail-built line-of-battle ship from Warrior’s 1860 commissioning. In that interval navies converted or built 112 steam rates, an extraordinary output for a technology still being learned. Several late wooden hulls were suspended, broken up, or redirected into ironclad conversions before completion. Technological transition produced overlapping programmes and sunk costs rather than a clean replacement.
Chapter · 39:56-43:08
A 21-year steam-rate era before the ironclads arrived
New screw ships proliferated between the last sail-built line ship and HMS Warrior, while unfinished wooden hulls were already being redirected into ironclads.