Why published warship performance needs industrial context

Published specifications reveal how a navy wants its strength to be perceived, not necessarily the full capability available in service. Conservative British figures for Queen Mary and Tiger are compared with higher trial outputs under forced draft. Some German battlecruiser performance assumptions also depended on high-quality Welsh coal and British-built Parsons turbine support. War against Britain removed access to both inputs, making nominal machinery figures less useful as a guide to wartime performance. An intelligence profile therefore has to connect speed and power claims with fuel quality, imported components, maintenance, and the conditions under which trials were run.