The LMI is an operational aid only.
The device is not, and shall not be, a substitute
for good operator judgement, experience and
The responsibility for the safe operation of the
crane shall remain with the crane operator who
shall ensure that all warnings and instructions
supplied are fully understood and observed.
Prior to operating the crane, the operator must
carefully and thoroughly read and understand
information in this manual to ensure that he
knows the operation and limitations of the
indicator and crane.
The PAT/LMI (Load Moment Indicator) System is an
electro-mechanical sensing and alarm system that
provides vital lift data to the operator. The system
senses current boom length, boom angle, and degree of
rotation as well as load boom weight. This data is
displayed on a control panel mounted above the
instrument panel in the cab. When an impending
overload condition is sensed, the system provides the
operator with visual and audible warnings. It locks out
the control levers to prevent lowering the boom,
extending the boom or raising the main/auxiliary hoist
cables. Antitwo-block devices prevent the hook block
from coming into contact with the boom nose. This
condition will also cause a lockout of the above
mentioned control functions.