Minimum root safety factor

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 will be 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 drive 1.80
Dual main drive 1.60
Yacht main drive 1.50
Yacht dual main drive 1.45
Auxiliary drives 1.40

To get the tooth root stress limit σFG the permissible tooth root bending stress σFP has to be multiplied by the minimum safety factor for root bending stress SFmin. The tooth root stress limit σFG divided by the root bending stress σF is resulting in the root bending safety factor SF.

Source: American Bureau of Shipping (ABS): Rules for Building and Classing Steel Vessels, Paramus, New Jersey - edition 2011 and 2019