Union Pacific’s Big Boy No. 4014: Waving the ‘Blue Flag’ for Safety

“What is it?” they ask, as crew members riding in a support car behind Big Boy walk up and toss their safety tags to the locomotive engineer in the cab.

It’s called a “blue flag” and is a critical safety tool that holds the custom made, individualized safety tag of each crew member and is plainly visible to the locomotive engineer, indicating crew members are “on, under or in-between” train cars servicing the steam engine.

“Like the flag says, safety is our first priority,” said Ed Dickens, senior manager-Heritage Operations, who has a unique role on Big Boy, serving as both the locomotive engineer and the person in charge of the servicing crew. “The blue flag is a critical part of how we keep watch over each other, making sure everyone is accounted for before the locomotive moves.”

Here’s how it works: whenever the locomotive comes to a service stop while on tour, the employee in charge – who is the locomotive engineer in the case of Big Boy - puts out the flag when the engine is stopped. This signals to the crew in the tool car – several cars behind Big Boy – that it’s safe to exit and service the locomotive. Big Boy needs to be serviced with grease and oil lubricants approximately every 80 miles, which is often done during whistle-stops.

Crew members then walk up to the locomotive and toss their safety tags – each one holds their photograph and name – up to the employee in charge, who hangs them on the blue flag. They may now service the locomotive.

When they are done, they report back to the employee in charge for their tag before walking back to the tool car that accompanies Big Boy wherever it goes. Just like the name says, it holds the tools, oils and lubricants needed to service the steam locomotive.