What precautions are required before coupling into cars or engines?

• A. Make coupling at speed not exceeding 10 mph.
• B. Only after signals.
• C. Proceed without any speed limit.
• D. Make coupling at speed not exceeding 4mph. After coupling, stretch the slack to ensure coupling was made.

Answer: (D)

Before coupling into cars or engines, the key safety step is to approach very slowly and verify the connection. Moving at a crawl—specifically not more than four miles per hour—keeps the risk of damage or injury minimal if the alignment isn’t perfect. This slow speed gives crews time to observe the coupler, ensure it’s lining up correctly, and prevent a hard impact if the lock isn’t fully engaged. After the connection is made, you stretch the slack to confirm the coupler is truly seated; if you can’t stretch the slack or if there’s little to no movement, the coupling may not be fully engaged and needs to be rechecked before motion. This combination of careful, low-speed coupling and a slack check helps ensure a safe, secure hookup.