Major ordnance works operated as security-conscious engineering organizations rather than open mass-production factories. Access to ordinary production and experimental development required different levels of trust, and the most sensitive workers were closely watched and well paid. Commercial rivals posed an industrial-espionage threat even when governments did not expect an immediate naval war. The secrecy around the 15-inch gun and the later public appearance of the 18-inch weapon on HMS Furious show how a visible programme could conceal earlier design paths.
Notable Point · 2:11:53-2:14:10
How ordnance factories protected secret gun work
British gunmaking firms compartmented sensitive work because rifling, metallurgy, and new weapons were valuable industrial secrets even when another navy was not an expected wartime enemy.