Narrow gauge train in Bulgaria (narow gauge: 760mm, standard gauge: 1,460 mm, broad gauge (e.g., in Ukraine): 1,524mm). I placed my phone there for reference.
It was mostly used on branch lines for cost reasons. not only is the hardware less expensive since you can use much lighter rails and sleepers and smaller rolling stock, but you can take sharper turns so you can avoid topographical obstructions instead of having to go through them.
UnitConversionBot
760mm ≈ 2 feet, 5 7/8 inches
UnitConversionBot
1,460 mm ≈ 57.48 thousandths of an inch
UnitConversionBot
1,524mm ≈ 60 thousandths of an inch
cosinewave
Some countries used narrow gauge rail to prevent invasion forces from using their rail infrastructure against them.
CakeShapedPie
Like the Iberian gauge.
LitterBoxKing
TIL
MrFancyPanzer
It was mostly used on branch lines for cost reasons. not only is the hardware less expensive since you can use much lighter rails and sleepers and smaller rolling stock, but you can take sharper turns so you can avoid topographical obstructions instead of having to go through them.
CakeShapedPie
Also common for mining cars and the like