Etymonline also offers two distinct derivations for the term “gauntlet”
“glove,” early 15c., gantelet, from O.Fr. gantelet (13c.) “gauntlet worn by a knight in armor,” also a token of one’s personality or person, and symbolizing a challenge, e.g. tendre son gantelet “throw down the gauntlet” (a sense found in English by 1540s)…
military punishment in which offender runs between rows of men who beat him in passing, 1660s, earlier gantlope (1640s), from Swed. gatlopp “passageway,” from O.Swed. gata “lane” (see gate) + lopp “course,” related to löpa “to run” (see leap). Probably borrowed by English soldiers during Thirty Years’ War. Modern spelling, influenced by gauntlet (1), not fixed until mid-19c.
At etymonline, “gantlet” redirects to “gauntlet.”
Due to its Old French ("glove" gantelet) derivation, I wonder if areas culturally influenced by French language such as New Orleans would be more apt to use the “gantlet” spelling? User BlackGrey suggests above, “...Gantlet would indeed have been closer to the old Germanic pronunciation of its predecessor as prounounced in the dialects of Northern England and Scotland at least,...”
I don’t use “gantlet” and I do not recall having seen it used in print. I suppose I may have heard it used but I would have likely taken it for “gauntlet” if so. (Northeast, Midwest, Southwest, and Northwest US)
For the “application in a technical railroad sense” Wikipedia offers this for the railroad term, “gantlet” and notes that it may also be spelled “gauntlet.”
I do know what a “gandy dancer” is—wikipedia link here—slang for railroad ‘maintenance of the way’ workers, basically laborers, usually workers on the tracks, or “way.” This railroad term “gantlet” may have something to do with the etymology of “gandy dancer.” In my travels, I heard by word-of-mouth that the term “gandy dancer” was used mainly by Irish immigrants.
Edited to add:
Note: The image above is a link.
Relevant text from the image:
BY THE WAY
What is a “gandy dancer”? The words were on a blackboard outside a store on the Bowery. In old times they might have suggested the proximity of a cheap dance house. But the Bowery has changed. Within the space of a few blocks there are now more than a score of “labor bureaus” where formerly were low dives and “suicide halls.” Inquiry of an Italian employee of the bureau elicited the information that a “gandy dancer” is a railway worker who tamps down the earth between the ties or otherwise “dances” on the track. The announcement read:
Men wanted for track work cinder ballast no rock straight time rain or shine paid weekly accomodation very good. Board furnished $5 per week. It is a good job particularly for veteran gandy dancers. It’s a few miles out and requires no weeks toil to get back to this burg.
Another bureau’s sign called for “gandy danzers,” a variation of the spelling....
[Edited to add missing punctuation in text quotes...]