5.5 Load Test
1. Raise and lower the hook through the
full-working distance of hook travel.
2. Run the hoist block into the limit switch or
switches, if installed, at slow speed.
3. Run the hoist block beyond the limit switch or
switches by using the bypass switch.
1. Raise and lower the boom through the
2. Raise the boom into the upper limit switch
(when installed). Raise the boom past the boom
upper limit switch using the bypass switch.
3. Test the lower limit switch (when installed) by
the same proecdure prescribed for testing the upper
4. Extend and retract telescoping boom sections
their full distance of travel.
5. Check the radius indicator by measuring the
radius at the minimum and maximum boom angle.
Other motions, including swing, shall be operated
through one cycle (one-full revolution of major
The load test consists of basically two parts: a
maximum load test and a stability test. The following
test sequence is time and cost cffcctivc. The sequence
may be varied by the activity.
5.5.1 Maximum Test Load for the Crane on Main
1. Static Test. Raise the test load to clear the
ground with the boom at minimum radius and hold for
10 minutes without boom and load hoist pawls (dog)
engaged. Rotate the load and hook to check bearing
operation. Observe any lowering that may occur that
may indicate a malfunction of the boom or hoisting
components, brakes, or outriggers. For hydraulic
cranes, tests are performed with the boom fully
retracted and fully extended.
2. Dynamic Test. Raise and lower the test load at
normal operating speeds. Lower the test load to the
ground until the hoist lines are slack. Wait 5 minutes,
hoist test load, and continue on with the test.
3. Hoist Brake. Test the ability of the brake to
control and stop the load (fig. 3-18). Test the ability
of the brake to hold and lower the test load with the
friction clutch disengaged, if applicable.
Figure 3-17.Marking hydraulic rams.
Figure 3-18.-Hoist brake.