Re: gauge railway workshop to yard

Gauges of mine railways - I've found - with a tape-measure:
18inch
22inch / 1ft 10inch
24inch / 2ft

Didn't know of 22inch gauge before - find that is/was also the gauge of
the railway around the Guinness brewery in Dublin, Ireland

Metric equivalent gauges which seem to exist elsewhere
18inch <=> 460mm
22inch <=> 560mm
24inch <=> 600mm

So, yes, didn't know of those.
A mine I am "volunteered to" has 18inch.
Friend I was thinking of when asking here - it did come down to what
he's managed to blag, and that is the 22inch gauge.

Okay - well, that's a more complex picture than I knew about.

Sorry if asked this already - if you wanted to lay line cheaply - you'd
go with flat-bar on its thin edge, welded to any steel you could find as
ties, set to gauge and with curvature, in-situ?  Bend the more
"restricted" - by clearance to things around, etc.? - first, and use a
gauging guide to set the other rail relative to it and weld-off to the
ties ("sleepers" in UK-speak) ?
Not sure how going to get a welding machine (electric) powered-up down
the mine, though.  No compressed-air-powered welding machine as I know
of... (?!).
(*
 90 ;; Amps
 20 ;; Volts
) ;; 1800
With 2.5mm 7018 you'd need 1.8kW - call it 2kW.

I commented as a question - down a mine you wouldn't need expansion
joints due to the near constancy of temperature?
Something like 100m of track might benefit from being re-laid anew.

Regards,
Rich S