Turnstile Entry File

Subways use turnstiles to count passengers and collect fares. In many cities, these turnstiles are networked to provide live data on station congestion.

This is likely a reference to the cryptographic from the video game Bioshock . turnstile entry

Different environments demand different levels of security and aesthetic appeal. Turnstiles generally fall into four primary categories: Waist-High Tripod Turnstiles Subways use turnstiles to count passengers and collect fares

Turnstile entry systems are the frontline of modern physical security. From subway stations and sports stadiums to corporate headquarters and manufacturing plants, these mechanical and electronic gates regulate the flow of people every day. Implementing a turnstile system requires careful planning

Implementing a turnstile system requires careful planning.

If you are looking for the solution to the puzzle in the game:

Tripod turnstiles use three rotating metal bars positioned at waist height. The mechanism unlocks via an access control signal, allowing a single person to push through the barrier.