Procedure 9-1 Design of Davits

Cy = vertical impact factor, 1.5-1.8 Ch = horizontal impact factor, 0.2-0.5 fa = axial stress, psi fb = bending stress, psi fh = horizontal force, lb fy = vertical force, lb Fa = allowable axial stress, psi Fb = allowable bending stress, psi Fj. = radial load, lb Fj-e = equivalent radial load, lb Fy = minimum specified yield stress, psi Ml = bending moment in mast at top guide or support, in.-lb 

M3 = bending moment in boom, in.-lb Mx = longitudinal moment, in.-lb M(A = circumferential moment, in.-lb 

Type 1 Ml = 2fvLi + O.SWiLi + fhL2 Type 2 Mi = fyLi + O.SWiLi + fhL2 

is maximum when davit rotation tj) is at 0°, for other rotations  

Note Fre may be substituted for and F as an equivalent radial load for any rotation of davit other than 0° or 90°. 

---