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|  MIL-T-740G
4.4.14.11 Braking ability test. To determine conformance to 3.4.9, through 3.4.9.2, the
vehicle shall be operated as specified and observed for distance to stop and hold vehicle. Brake
stopping distance shall not exceed that specified.
4.4.14.12 Cramping angle test. To determine conformance to 3.4.10, each vehicle shall be
cramped as specified, and observed for performance requirements.
4.4.14.13 Crane lifting capacity tests. To determine conformance to 3.4.11.1 through
3.4.11.1.5, all tests see (4.4.14.13.1 through 4.4.14.13.3) shall be performed with transmission in
specified gear and engine operating at specified speed. Oil temperature for hoist mechanisms
shall be no less than 100F. All tests shall be performed so as to demonstrate performance
requirements when operating on level ground and on slopes fore and aft to either side up to
5 degrees.
4.4.14.13.1 Outriggers (not in use) test. Test shall be conducted without using outriggers
with 3000 pound test weight for the M543A1, M543A2, and M816 trucks, and with 1700 pounds
for the M246A1, M246A2, and M819 trucks and with boom extended to maximum radius.
Elevate and lower load using lifting cylinder(s). Swing boom to right and lower load using hoist
winch. With load partially raised, swing boom right to left 180 degrees with stops in place, and
360 degrees without stops in place, for determination of 3 or 4 rpm traversing rate. Repeat for
three cycles for each condition. Using a 3000 pound load with boom fully extended and
elevated, raise and lower the load, using the hoist winch to determine a line speed of not less than
54 feet per minute for the M543A1 models, all series, and not less than 60 feet per minute for the
M246A1 models, all series. Repeat for three cycles. Perform tests extending and retracting
boom simultaneously lowering and raising a load using the hoist winch. The other tests, without
the determination of traveling rate and line speed, shall be repeated until a total time of
40 minutes has elapsed.
4.4.14.13.2 Outriggers (in use) test. To determine conformance to 3.4.11.1.2 and 3.4.11.1.4,
test shall be conducted as specified in 4.4.14.13.1, except that the test weight shall be
10,000 pounds with the outriggers in position, and the load radius limited to minimum boom
length on either side of the wrecker and increased only sufficiently for the load to clear the
outriggers and the rear of the vehicle. The rate of traversing or line speed tests are not required.
The payload shall be raised 20 inches above the ground and the vertical drift (rate of descent)
observed after stabilization of system with power shut off. The rate of descent shall not exceed a
total of 3 inches for a six minute period. Test shall be repeated three times with the crane in each
of the three positions; center, 90 degrees to right of center, and 90 degrees to left of center.
4.4.14.13.3 Three part line test. Test shall be conducted using a 20,000 pound test weight, a
three part line, the boom extended to a 15 foot radius supported by boom jacks, and front
outriggers in place. Raise and lower test weight approximately 4 1/2 feet for three cycles.
Repeat the same test, except that the load radius shall be limted to minimum boom length, the
boom supported from vehicle, and the outriggers in place. Test shall be performed for three
cycles.
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