Crane center
of rotation
Boom
heel pin
Boom
angle sensor
Luffing jib
angle sensor
SLEW OFFSET
BOOM TOP LENGTH
BOOM TOP OFFSET
ANGLE
MAIN BOOM
TIP HEIGHT TOLERANCE
BOOM TOP LENGTH
& OFFSET ANGLE
FIXED JIB LENGTH
& OFFSET ANGLE
LUFFING JIB LENGTH
(CENTRE SHEAVE TO
CENTRE SHEAVE)
LATTICE EXTENSION
LENGTH & OFFSET ANGLE
JIB MOUNTING POINT
PARALLEL & PERPENDICULAR
BOOM LENGTH
includes boom top
LATTICE EXTENSION LENGTH
LATTICE EXTENSION OFFSET
ANGLE
Extensions, two possibilities:
1) MANUAL LENGTH: the offset is
always zero degrees.
2) LATTICE EXTENSION LENGTH: the
offset angle must be adjusted.
Typical sheave heads:
• SHEAVE HEAD LENGTH PERPENDICULAR = D1
• SHEAVE HEAD LENGTH PARALLEL = 0 (typical)
Special top sheaves
(example: rooster):
• SHEAVE HEAD LENGTH
PERPENDICULAR = D2
• SHEAVE HEAD LENGTH
PARALLEL = D3
D2
D1
D3
BOOM FOOT
HEIGHT OFFSET