| Symbol | SFmin |
|---|---|
| Unit | - |
| Attribute-ID | abs_minimum_safety_factor_root |
| Numeric ID | 5354 |
| Value Type | PMDouble |
The required minimum safety factor for root bending stress SFmin is used to calculate the permissible tooth root bending stress σFP.
The following options are available acc. to ABS 2011 and ABS 2019:
| System type | SFmin |
| Main propulsion gears | 1.80 |
| Duplicated (or more) independent main propulsion gears | 1.60 |
| Main propulsion gears for yachts, single screw | 1.50 |
| Main propulsion gears for yachts, multiple screw | 1.45 |
| Auxiliary gears | 1.40 |
To obtain the tooth root stress limit σFG, the permissible tooth root bending stress σFP is multiplied by the minimum safety factor for root bending stress SFmin. The tooth root stress limit σFG divided by the root bending stress σF results in the root bending safety factor SF.
Source: American Bureau of Shipping (ABS): Rules for Building and Classing Steel Vessels, Paramus, New Jersey - 2011 and 2019 editions