Sentence:  "It took me about a month to <WSD>pass out</WSD> on this box," he adds. "It's easy to be daunted by all the levers and bell codes and Absolute Block, but it's all the usual rules of anywhere else. You can't just come up here from the street though, and I thought I'd never be able to work this SB <small>[signal box]</small>, but you just get on with it until it becomes second nature." 
Meaning of the word marked with <WSD> tags:  (by extension) To become proficient in a particular job or task