‘Big Boy’ passes early pressure test

‘Big Boy’ passes early pressure test

By Angela Cotey | February 6, 2019

| Last updated on January 26, 2021


Hyrdostatic test means Union Pacific crews can continue readying the 4-8-8-4 steam locomotive for service

CHEYENNE, Wyo. — Union Pacific’s Big Boy is another step closer to running this year after it passed a Federally required hydrostatic test.

Union Pacific posted a video on YouTube Wednesday showing workers knocking on the locomotive with hammers while pressurized water filled the boiler.

One scene shows a pressure gauge at 300 pounds per square inch.

In a separate video, Union Pacific Senior Manager of Heritage Operations Ed Dickens speaks on camera about the test. A hydrostatic test is required by Federal Railroad Administration rules to confirm that a steam locomotive’s boiler will be able to handle the heat and pressure of steam.

News of the test was distributed by the Union Pacific Steam Club.

Share this article