Enhanced Fujita scale damage indicators and degrees of damage, chapter 30
C-5 Farm Silos or Grain Bins (C-FSGB)
Typical Construction:
Farm silos
- Cylindrical structures typically 4-10 m in diameter and 20-50 m in height
- Construction is wood staves, concrete staves, cast concrete, poured concrete or steel panels
- With cast/poured concrete and Harvestore steel silos, increase toward upper-bound wind speed
Grain bins
- Cylindrical structures typically 5-20 m in diameter and 5-30 m in height
- Construction is galvanized steel panels and purlins
| DOD | Damage Description | EXP* | LB* | UB* |
|---|---|---|---|---|
| 1 | Empty unanchored grain bin toppled; anchored grain bin damaged; silo cap damaged | 90 | 70 | 110 |
| 2 | Empty unanchored grain bin rolled or carried through air less than 10 m; anchored grain bin toppled; silo cap removed | 135 | 110 | 160 |
| 3 | Anchored grain bin rolled or carried less than 10 m; empty portions of silo destroyed | 180 | 150 | 210 |
| 4 | Grain bin carried 10-100 m or more; silo destroyed | 225 | 190 | 260 |
*All wind speeds in km/h