Every Soldier knows that the weapons and munitions
he uses have been tested thoroughly and are subject to strict
quality control. The reason for this care is obvious: Weapons
and munitions must work properly and safely every time. But
probably few Soldiers know that the containers used to transport
munitions receive the same high level of testing and must comply
with standards just as exacting as their contents.
The OD (“olive drab”) metal container—the one that can work
as a tool box as well as an ammunition box—has an entire team of engineers
behind it that has designed, tested, redesigned, and retested it to meet the
warfighter’s needs. Every container currently being fielded is designed
to protect its contents for at least 20 years through the worst conditions possible.
The people who test these containers are packaging engineers. In the hands of
these dedicated professionals, the “ammo can” has matured from wooden
crates to high-tech, Soldier-proof, insensitive ammunition containers. [Insensitive
containers will resist explosion when engulfed by fire or hit by small arms fire
or fragments from larger ordnance.] The process is intensive, but the result
is a container that provides full life-cycle protection of ammunition.
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| Containers
of 25-millimeter linked ammunition are transported
through the desert during an exercise at the National
Training Center at Fort Irwin, California. |
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Design
The first step in the container design process
is to configure the basic overall envelope. When ammunition
is small
enough to fit many rounds in a box, the container
used is usually rectangular. Missiles or larger shells generally are packaged
in big metal tubes with square brackets welded in the middle and on the ends
to permit stacking.
The next step is to determine the internal configuration of the container.
An internal support system is usually placed inside the outer package. For
some
rounds, this can be simple foam padding; for others, a complicated plastic
support is required.
Testing
Generally, the first series of tests for a newly designed container is outlined
in Military Standard (MIL–STD)–1904, Design and Test Requirements
for Level A Ammunition Packaging. The tests are designed to see if the round
will be protected during transportation and that it will arrive at the firing
line intact and functional. Dropping is the most common abuse of an ammunition
container, so the testers drop them—over and over again.
The first drop test simulates a Soldier accidentally dropping the container.
The height depends on how large and heavy the round is. For most packaged
rounds that weigh less than 150 pounds, the first drop is 3 feet. The second
drop
is from 7 feet, which simulates a package falling from a truck or hovering
helicopter.
During these drop tests, containers of dummy rounds are dropped in every
way possible, hitting every edge. Three feet may seem like a short distance,
but
a 100-pound container dropped only a few feet lands with a great deal of
force. Through these tests, each container must be able to maintain an internal
overpressure
of 3 pounds per square inch to ensure that moisture is kept out. This overpressure
must not be released during drops (except for a few exceptions during the
7-foot drop), and the container must be usable afterward.
These drop tests demonstrate what happens when containers are dropped shorter
distances, but what happens if a crane drops a pallet of containers while
loading a ship? Those containers are likely to fall much farther than 7 feet,
so the
next test is a 40-foot drop. Although few containers come through unaffected
and still sealed when dropped that distance, they pass the test as long as
the rounds inside remain safe to handle.
The next series of tests involves vibration. The first, a “loose cargo
test,” simulates a loose container rattling around in the back of a truck.
The second vibration test simulates a situation in which the container is tied
down. The third simulates transport of the container in the storage rack of its
intended tactical vehicle during typical operations. For all of these tests,
the item must be protected and the container still must function as intended.
Containers also must be tested in different environmental conditions. There
is a big difference between dropping a container from 40 feet in Iraq in
the middle
of summer and from 40 feet in Alaska in the middle of winter. In addition,
when an Air Force cargo aircraft is at cruising altitude, the temperature
in the cargo
area routinely drops far below zero. So, to make sure ammunition stays safe
no matter its location, every one of these tests is done at three different
temperatures: –65
degrees Fahrenheit, +73 degrees Fahrenheit, and +160 degrees Fahrenheit.
The container also must stand up to corrosion tests, 20-year accelerated
aging tests, electricity conductivity tests, water transmissibility tests,
and burning
tests.
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A container
is subjected to a heat-conditioned 7-foot drop test
at Picatinny Arsenal, New Jersey. |
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Ensuring Insensitivity
All of the tests are designed to ensure that packaged ammunition is protected
from the rigors and hazards of transportation and the environment. But how
is the Soldier protected from the ammunition? The answer is to make the
containers
insensitive. Another series of tests—outlined in MIL–STD–2105C,
Hazard Assessment Tests for Non-Nuclear Munitions—is
used to examine this aspect of packaging. This series of tests includes fragment
impact, bullet impact, fast cook-off, slow cook-off, shape-charge jet impact,
and sympathetic detonation.
Ongoing Testing
Testing does not end at production. Every year or two, depending on the container
configuration, performance-oriented packaging (POP) testing must be conducted.
These tests are designed to ensure that nothing has changed. To make sure that
containers in a palletized configuration will stay together, the MIL–STD–1660,
Design Criteria for Ammunition Unit Loads, test is conducted. Transportability
Testing Procedures, TP–94–01, are used to ensure that palletized
loads will survive transportation.
The Logistics Research and Engineering Directorate at Picatinny Arsenal, New
Jersey, tests ammunition containers to ensure that the ammunition shipped in
them will reach Soldiers intact. The various tests conducted on the containers
are designed to simulate any damage or hazard that the containers may encounter
during shipment and delivery. The ultimate goal of these tests is to ensure Soldier
safety.
ALOG
Robert M. Forrester is an engineer with the
Armament Research, Development and Engineering Center’s Armament
Systems Integration Center, Logistics Research and Engineering
Directorate, at Picatinny arsenal, New Jersey. He has a bachelor’s
degree in mechanical engineering from Virginia Polytechnic
Institute and State University and is pursuing a master’s
degree in mechanical engineering through Stevens Institute
of Technology in New Jersey.