The most common and most likely answer to this crossword clue is the 10 letter word COWCATCHER
I've seen this crossword clue in The Guardian
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More clues leading to the result COWCATCHER
- Crouch down, about to pick up frame on US train
- Part of a US locomotive that’s for rolling stock?
- Lasso part of train?
- Old loco‘s gaucho
- Contract secured by quail for device used on American rails
- In retreat, notice US train line clearer?
- Clear tracks are provided in the US by this singer to intimidate jazz fan at the start
Buddy explains!

The straight part
We know that "device used on American rails" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case device used on american rails = cowcatcher.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does COWCATCHER mean?
COWCATCHER noun- The V-shaped device on the front of a locomotive (or other large vehicle) shaped so as to push objects on the tracks out of the way, to prevent major damage to the train.
- An advertisement at the start of a programme.