Re: 190,000lb of thrust?
"The reason for the width has something to do with horse's arses:
It's a lovely explanation which feels like it ought to be true, but alas Snopes says it's not exactly right.
https://www.snopes.com/fact-check/horses-pass/ has a lot to say, including these points:
'This item is one that, although wrong in many of its details, isn’t completely false in an overall sense and is perhaps more fairly labeled as “Partly true, but for trivial and unremarkable reasons.'
'Over and above our love of odd facts, this tale about railroad gauges succeeds because of the imagery of its play on words: space shuttle technology was designed not by a horse’s ass (figuratively, some overpaid government know-it-all) but because of a horse’s ass (literally, the width of that particular portion of equine anatomy). People find this notion amusing, feeding the story’s popularity as charmed readers continue to pass it along to others in a cascade of forwards.
“Very interesting, educational, historical, completely true, and hysterical”? One out of five, maybe.'