Unsupported length versus fill weight
X axis: Unsupported length in m FLB/FLG
Y axis: Fill weight in kg/m
Lower scale: Travel S in m
FLB = Unsupported with permissible sag
FLG = Unsupported with straight upper run
Reference example A:
Fill weight = 1,5 [kg/m]
Unsupported length FLB = 1,3 m
Travel = 2,6 m