Enter the component of the force on the lifting lug/trunnion tangent to the wall of the vessel. This load will cause a major axis bending stress on a perpendicular lug and a minor axis bending stress on a flat lug.
CodeCalc assumes that the magnitude of the applied loads is acting on one lug or one trunnion. Typically vessels are lifted with 2 (or more) lifting lugs/trunnion, thus the load is divided between them. An option is to analyze the lug/trunnion with the maximum load, acting on that lug/trunnion, during the whole lift.
The program multiplies this lifting load by the importance factor specified by the user.