This paper presents the equations needed for design engineers to check the
stability of precast concrete beams when simply supported, during transport
ation, when being lifted and while sitting on flexible bearings. It shows h
ow the critical loads can be determined and how estimates can be made of th
e effect of imperfections both in the beam itself and in the degree of leve
lness of its supports. It shows how the stresses induced by second-order ef
fects in imperfect beams can be determined. Various examples are given of t
he method in use.