- Complete Bundle with Solutions & Graded A
Answers
A 200-ft hammer-head tower crane is being climbed to a new 180 ft height. The climber
frame is fully engaged and the climbing ladder is 12 ft long. Before releasing the
tower-top pins to begin the climb, you must verify that:
1. A) The pin shear rating equals the maximum climber load shown on the load
chart
B) The pins are removed completely so the tower can slide freely
C) The load-moment indicator is recalibrated for the new height while climbing
D) The climbing ladder rungs are lubricated to reduce friction
Answer: A
Rationale: OSHA 1926.1435(b)(3) requires that all pin connections used during climbing
have a shear capacity at least equal to the maximum forces developed during the
climbing operation. Calibrating the LMI mid-climb (C) is unsafe; pins must remain
captive (B wrong); lubrication (D) is not a code requirement and can create slip hazards.
While operating a saddle-jib tower crane, you notice the load-moment indicator (LMI)
alarm sounds at 85 % of chart but the load is still 3 t below the charted capacity for that
radius. Wind is 12 mph. Your first action is to:
2. A) Continue the lift slowly because the chart still allows the load
B) Swing the load in toward the tower to reduce radius and silence the alarm
C) Stop all hoist and travel functions and determine why the LMI is pre-alarming
D) Reset the LMI system and resume hoisting
Answer: C
Rationale: ASME B30.3-2024 para. 3-2.2.1 requires the operator to cease operations
when an overload warning occurs and investigate the cause. The LMI may be correctly
sensing hook/load weight plus dynamic effects not shown on the static chart.
,Continuing (A) or swinging in (B) overrides safety; resetting (D) violates OSHA
1926.1416(d).
A tower crane is to be erected on a new parking-deck slab with a design compressive
strength of 4 000 psi. The crane manufacturer’s manual requires 3 000 psi minimum for
the specific base-plate loading. The slab is 14 days old and field-cured cylinders
averaged 3 200 psi this morning. The appointed person’s plan says “proceed.” You
should:
3. A) Refuse to erect until 28-day strength is verified
B) Accept the plan because the current strength exceeds the manual minimum
C) Demand additional blocking under the base to spread the load
D) Request a written professional-engineer confirmation of the in-place strength
for the specific loads
Answer: D
Rationale: OSHA 1926.1402(a)(2) requires the foundation/supporting surface be firm,
graded, drained, and sized to support the crane per a qualified person. A PE letter
documenting that 3 200 psi is adequate for the specific base reactions satisfies the
standard. Simply exceeding 3 000 psi (B) ignores safety factors; waiting 28 days (A) is
unnecessary if PE confirms.
During a pre-climb inspection you find one anti-two-block (A2B) limit switch on the main
hoist has been bypassed with a jumper wire. The crane is otherwise ready to climb 40 ft.
You must:
4. A) Remove the jumper, test the switch, and document the repair before climbing
B) Tag the switch “out of order” and climb only with reduced load
C) Leave the jumper in place until the climb is finished, then repair
D) Use the auxiliary hoist for the climb and fix the main hoist later
Answer: A
Rationale: OSHA 1926.1415(d)(3)(ii) mandates that A2B devices be operative; a bypass
(jumper) is a citable violation. The device must be restored and tested before
, operations—including climbing—commence. Climbing with reduced load (B) or using
another hoist (D) does not correct the violation.
A 2-leg chain sling (grade 100, ⅜ in. dia.) is reeved around a 14-in. square concrete
column and hooked back to the master link at a 60° included angle. The hitch is:
5. A) A choker hitch with 100 % of sling capacity
B) A basket hitch whose capacity is derated by the angle to 86 %
C) A choker hitch whose capacity is reduced 25 % due to pinching
D) A basket hitch with full 100 % capacity because angle < 90°
Answer: C
Rationale: ASME B30.9-2021 Table 9-2.1 shows a choker hitch loses 25 % capacity due
to pinching regardless of angle. The configuration described is choker, not basket,
because the legs are hooked back into the master link, not terminated at separate
points.
A tower crane operator is signaled to “boom up” during a 40 mph gust. The load chart
states “reduce to 70 % capacity when wind > 32 mph.” The current load is at 65 % of
chart. You should:
6. A) Boom up slowly while keeping the load in view
B) Stop the hoist, lower the load to the ground, and cease operations
C) Swing the load to the lee side of the tower and continue
D) Boom down to reduce sail area and finish the lift
Answer: B
Rationale: OSHA 1926.1435(a)(5) prohibits hoisting when wind exceeds manufacturer
limits; the chart’s 32 mph cut-off is mandatory. The operator must land the load and
cease operations. Attempting to boom up/down (A, D) or swinging (C) prolongs
exposure.
A hammer-head tower crane’s jib is fitted with a 2-line runner (whip line) on the main
trolley. The operator feels “slack” in the runner when the hook is at low radius. The most
probable cause is: