Train Alarm Chain: How it Stops a Train & What Happens if You Pull it Wrongly

• Train brakes operate on 'Air Pressure'; pulling the chain opens an 'Air Valve', releasing pressure and automatically engaging brake shoes.
• Loco pilot detects a chain pull by a drop in the 'Air Pressure Gauge' needle, a loud 'shooosh' sound, and modern engine alarms.
• Railway staff identify the exact coach via an 'Alarm Check Valve' on the exterior, which shows a red lever or emits a continuous sound.
• Pulling the chain without valid reason is an offense under Section 141 of the Indian Railways Act, 1989, punishable by fine or imprisonment.
• Valid reasons for pulling the chain include fire, critical health emergency, a child/elderly person left behind, or theft/robbery.

Why It Matters: Train alarm chains use pneumatic engineering to stop trains, but misuse carries legal penalties.