Basic Mechanisms In Fire Control Computers (1953) [video]

Original Article ↗ Hacker News Discussion ↗

Analog & Mechanical Computing

  • Commenters are fascinated by how fire-control computers implemented math mechanically (cams, gears, differentials) and how intuitive this makes abstract concepts like algebra feel.
  • Analog systems are described as “almost instantaneous” and continuous, but others note real delays from backlash, inertia, friction, heating, and mechanical limits.
  • Precision tradeoffs: analog/ mechanical systems suffer from machining tolerances, temperature changes, and accumulated error; digital systems avoid these but introduce quantization error.
  • Some tasks are easier and more “natural” on analog machines (e.g., certain continuous functions), even if digital wins overall on speed and flexibility.

Historical Context & Naval Applications

  • Fire-control and navigation are framed as major historical drivers of computing and mathematical innovation, especially in naval and artillery contexts.
  • Tide-predicting machines and marine chronometers are cited as early “computers,” with tide machines being militarily significant in WWII amphibious operations.
  • WWII and Cold War-era mechanical and analog computers appear in battleship fire-control systems, submarine torpedo targeting, and early torpedo programming.
  • There’s discussion of torpedo guidance: some call gyro-based control “inertial guidance,” others argue true inertial systems must integrate motion to estimate position.
  • Dangerous failure modes (e.g., torpedoes running in circles and sinking their own submarines) are noted, as well as lasting cultural effects on officer trust in new tech.

Educational Films & Pedagogy

  • Many praise the 1950s Navy training film’s clarity, pacing, and lack of modern “clickbait” tropes.
  • Older industrial and government training films (differentials, wave behavior, punch card machines, hand tools) are widely recommended and often judged superior in substance to contemporary educational videos.
  • The difficulty of pre-digital editing likely forced better planning and scripting.
  • Several argue that teaching quality and instructional design matter far more than production tech; ideal content pairs domain experts with instructional designers in tight feedback loops.

Related Technologies, Media, and Experiences

  • Other analog/ mechanical technologies mentioned: magnetic amplifiers, hydraulic automatic transmissions, mechanical engines and valve trains as “computers.”
  • Numerous links to additional videos, manuals, and pamphlets on fire control, electronics training, and WWII weapons systems.
  • Personal anecdotes from visitors and veterans underscore how impressive, power-hungry, and maintenance-intensive these mechanical computers were, and how rare the expertise to operate and repair them has become.