High speed on water required machinery with a strong power-to-weight ratio and a hull capable of planing. Thornycroft's 1876 torpedo boat HMS Lightning paired a narrow, easily driven hull with reciprocating machinery and became a forerunner of the destroyer. Its 81-foot waterline length and two-cylinder compound engine of just 390 ihp allowed it to reach 18.5 knots. Parsons's turbine-powered Turbinia demonstrated 35 knots at the 1897 Fleet Review. Nineteenth-century patents also described stepped hydroplanes intended to lift the hull and reduce its draft at speed. An 1877 patent proposed injecting air under pressure beneath the step. These examples place the motor torpedo boat within a longer line of technical development.
Notable Point · 16:00-17:24
Planing hulls and light machinery unlock high speed
HMS Lightning, Turbinia, and patented hydroplanes trace the two essentials of fast coastal craft: light powerful machinery and a hull that can plane.