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|  MIL-G-24477(SHIPS)
APPENDIX
If setpoints are obtained in this manner, however, the contractor shall
document the pre-test status of all adjustments, dimensions, and character-
istics that could possibly cause change of setpoints as a result of shock
test damage. If the contractor desires that certain aliqnments, clearances,
or setpoints be established by the shock testing facility as the equipment
is erected for shock tests (necessary, for instance, if equipment is dis-
assembled for shipment) , the cognizant shock testing facility shall be so
informed at least 2 months before the equipment is to be delivered to the
shock testing facility. Due to facility limitations, the contractor may
be required to provide personnel or equipment, or both, necessary to
accomplish such work.
40.3 Equipment mounting during test
40.1 Heavy weight equipment. Shock tests shall be conducted on the floating shock
test platform specified in MIL-S-901.
40.3.1.1 Where equipment is expected to be used in various shipboard applications
involving different locations, the generator set package shall be mounted on a typical ships
foundation welded to the inner dock of the test barge. Equipment intended for one particular
application only may be mounted on a foundation simulating that involved in the installation.
Deck mounted detached accessories, if tested with the generator set package shall be mounted
on a fixture designed to accommodate the accessory and welded to the inner deck.
40.4 Test procedures. Shock tests shall be conducted in accordance with MIL-S-901 and
as specified hereinafter.
40.4.1 Equipment need not be operated or energized durinq each blow or shot except for
the last blow or shot required by MIL-S-901. Prior to each blow or shot, however, the
generator set shall be run at rated speed and voltage, no load, for a period of time necessary
to determine that all components are functioning normally. In addition the generator set
shall be operated at rated speed and voltage, no load during the last blow or shot. com-
ponents and accessories, attached or detached, which contain a fluid during normal operation,
(such as coolers, and so forth) shall contain a fluid of comparable weight during all blows.
The equipment shall be examined for damage after each blow. Correction of minor damage during
the progress of tests will be permitted and the test may proceed to the next level of shock
after the minor damage is corrected. Major damage shall be cause for rejection and suspension
of tests until such time as the suppliers proposed corrective action is approved by the
command or agency concerned. In such cases, after corrective action is completed, re-test
will be required starting at the test level which caused the damage. The decision as to
whether damage is minor or major shall be made by the representative(s) of the command or
In case of disaqreement, the matter shall be referred to
agency concerned at the test site.
the command or agency concerned for final decision.
40.4.2
Instrumentation and measurements durinq the tests shall be as follows:
Velocity pickups, high speed movies, instrumentation for monitoring set
(a)
operation, and provision for remote shutdown shall be installed.
Initial start-up and check-out shall be conducted under guidance of the
(b)
manufacturer .
During the last blow or shot an oscillograph recording shall be made showing
(c)
generator output voltage and frequency characteristics from a time beginning
with 5 seconds before the blow until 30 seconds after the blow.
Scribe lines or punch marks shall be used to indicate exact location of all
(d)
major attached accessories and components (such as blowers, pumps, generator
feet, end covers and so forth) prior to shock tests so that any relative
motion during shock blows can be measured and recorded.
Generator shaft run-out shall be measured before starting test and after
(e)
each blow.
Air-gap measurements shall be taken before start of tests and after each blow.
(f)
Crankshaft deflection shall be checked prior to start of test and after each
(g)
blow , if feasible (measurement to be made by the vendor's representative).
With the set operatinq at rated speed, first order vibration levels shall be
(h)
measured with a vibration pick-up in the X, Y and Z directions before and
after each shot.
Insulation resistance and dielectric strength shall be measured prior to
(i)
start of testing and after final blow.
A thorough visual examination shall be made after each blow and any indica-
(j)
tions of movement or distortion recorded.
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