Driving blind: NYC subways steered by 1930s tech, paper maps and a lot of hope - Gothamist

The safe movement of subway trains on and off the Manhattan Bridge in downtown Brooklyn relies on what was once one of the most state-of-the-art, sophisticated systems in the world.

But that was the 1930s.

Nearly a century later, the technology that direct trains through the array of tracks known as the DeKalb interlocking looks like it belongs in a museum.

Each day, around 350,000 people ride the B, D, N, Q and R lines that pass through the interlocking. Regular commuters in Brooklyn are likely familiar with the area — it’s where trains frequently pause for seconds or minutes near the DeKalb Avenue station so others can pass. That delicate dance is managed by MTA staff behind a locked door, operating equipment invented when Franklin Delano Roosevelt was in the White House.