HOIST TO BOOM ALIGNMENT
Draw a line between the hoist drum
flanges, passing through both points as
located above and determine the midpoint.
Lower the boom to the level position.
Find the midpoint of the lines drawn across the
Find a line on top of the hoist drum which is
top of the base boom section, perpendicular to its
parallel to the drum axis as follows.
length, at both ends of the boom section. (Figure
points A and B).
Use a Miracle Point Gauge and find a
zero degree dial point next to each flange on
Check as follows to see if the hoist is aligned
top of the drum.
perpendicularly to the boom.
String a chalk line from point A, (outer
boom centerline) across the base section
If this special equipment is not available,
centerline and the hoist drum midpoint.
sufficient accuracy in locating a center-
line may be obtained by using a steel
Pull the line taunt, aligning it directly over
square against the machined inner
the top of point B.
surfaces of both flanges. It is advisable
to avoid using any cast surfaces in this
With a protractor, measure the angle be-
procedure unless a check from both
tween the chalk line and the cross line drawn
flanges indicates that the resultant line is
on the hoist. If the measurement of the angle
exceeds 90 degrees degree, realignment
will be necessary.
Figure 2-11-4. Hoist to Boom Alignment