Space Pioneers 3M.zip is a release file of the Minecraft resource pack Space Pioneers 3-Meter Gauge - Immersive Railroading, made for Minecraft 1.12.2. It was published on September 17, 2023 and is 13.8 MB in size. For the full description, screenshots and every other version, visit the Space Pioneers 3-Meter Gauge - Immersive Railroading resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.