Mueller Pre-Fab - Manual (Page 26)

877-2-MUELLER C-6
RaIsInG RIGID fRaMes (conTInUeD)
lifting cables and spreader bars
In all instances the length of the lifting cables should be such that the angle between the rafter and
the lifting cables is no less than 45 degrees . To reduce the severe compression stresses at the
ridge of the rafters that are created by the angle of lifting cables, a spreader bar is recommended,
which allows the lifting cables to be parallel to each other .
noTe: Drawing above is intended as a general rigging method.
actual rigging method will vary with member configuration.
noTe: stay well in the clear of loads being moved by any lifting device.
Hands and feet should be kept clear of moving loads and never stand
under a load being lifted. Remember, safeTY fIRsT!
Rafters
Spreader bar
45 degree
minimum