The red line indicates the optimal top of the salt pile. In a Monolithic Dome, the red line is naturally so high, it would be difficult for a front end loader to push the pile past the red line.
Image by South Industries
Sourced from Monolithic Commons
Salt Storage Dome Satisfies Madison Heights
CC BY-SA 4.0
Image by South Industries via Monolithic Dome Institute (CC BY-SA 4.0)