Union Pacific “Big Boy” Number 4014

Interactive Backhead Photo

What does that button, valve, lever, gauge, light, knob, etc. actually do???

Back on our website by popular demand!

The backhead of a steam locomotive is the end of its firebox facing inside the cab. Most of the locomotive’s controls used by the locomotive’s engineer and fireman are mounted on the backhead. All the gadgets needed to control the firebox’s fuel intake, boiler’s steam pressure, the locomotive’s acceleration on the track, and a whole lot more are within easy reach of its crew.

Just hover your computer mouse over any item shown on the Big Boy #4014 backhead photo, and a description appears under the photo. If only operating a steam locomotive was this easy.

This photo illustrates the controls of a coal burning firebox used in Big Boy #4014’s 18 year operational history. This photo was taken while in RailGiants Train Museum before Union Pacific required it. Now that its restoration is complete with an active oil burning firebox, it looks much different today as many controls have been replaced and repositioned.

Ash Pan Sprinkler Main Valve Firebox Door Left Rear Ash Pan Sprinkler Valve Left Front Ash Pan Sprinkler Valve Right Rear Ash Pan Sprinkler Valve Right Front Ash Pan Sprinkler Valve Boiler Feedwater Adjustment Valve Spill Light Squirt Hose Valve Firebox Jet Valves Stoker Operating Valve Respirator Air Valve Stoker Booster Valve Injector Lever Steam Supply for Firebox Jets Firebox Door Air Valve Blower Steam Valve Stoker/Firebox Steam Jets Gauge Feedwater Pump Pressure Gauge Boiler Pressure Gauge Steam Heat Pressure Gauge Stoker Engine Lubricator Steam Heat Valve Lubricator Drain Valve Lubricator Steam Valve Dynamo Steam Valve Boiler Water Sight Glass Assmbly Firebox Door Pedal Grate Shaker Access Points Auger Access Door Grate Shaker Access Points Air Brake Feed Valve Live Steam Injector Lever Bell Valve Sander Valve Train Control Acknowledge Lever Train Brake Lever Firebox Door Air Supply Valve Front Cylinder Cocks Valve Rear Cylinder Cocks Valve Emergency Steam Valve Locomotive Brake Lever Reverse Gear Lever Blowdown Lever Boiler Steam Pressure Gauge Brake Gauges Headlight Control Train Control Lights Back Pressure Gauge Throttle Throttle Whistle Lever Tri-cock Valve Tri-cock Valve Tri-cock Valve Blowdown Cock Shutoff Valve Boiler Water Sight Glass Assembly Air Compressor Steam Supply Roof Access Door