The controls for a steam locomotive are complex. This engineer, standing in the cab of the Central Pacific’s 4-4-0, Jupitor, at Promontory Summit, Utah, on May 10, 2014, must manipulate numerous levers and monitor many gauges. Two men operate a steam locomotive: the engineer who drives it and the fireman who feeds fuel into the firebox to heat the water to produce the steam to drive the pistons. It took several years of training and experience before a railroad in the mid-1860s would qualify a man to serve as engineer. It was a job reserved for men in those days, because railroading was considered too dangerous for women.
My post of May 18, 2015, provided a YouTube video on how the steam locomotive operated mechanically. You may want to go back to that post to familiarize yourself with the operating process before studying the details of the controls that make it all work.
A nearby diagram presented by the Nevada State Railroad Museum allows a side-by-side comparison for identifying the controls facing the engineer in the Inyo. I apologize for the glare from my camera’s flash, but if you click on the photo a couple of times it will expand so that you can more easily read the legend.
During the 2014 annual convention of the Railway & Locomotive Historical Society in Ely, Nevada, I climbed into the cab of Nevada Northern’s #40, a 4-6-0, built around the turn of the century, to survey the engine’s controls and talk with the engineer. This locomotive possesses many safety improvements from what was available on the 4-4-0s that Will Braddock encounters in Eagle Talons, Bear Claws, and Golden Spike in The Iron Horse Chronicles, but the operating principles remain the same.
In this photo, the NNV engineer has his hand on the Johnson control of #40 in preparation for putting the engine into forward motion.
This link to the WikiHow website provides a six-step sequence of what the engineer does to operate the locomotive: http://www.wikihow.com/Drive-a-Steam-Locomotive . You have to put up with some advertising on this site, but it provides a good explanation of the process of getting underway with an “iron horse.” Scroll down the page to view the six steps.