Jim Shaw, EVP of Engineering at Crystal Group, discusses the importance of MIL-S-901 testing.
MIL-S-901D Shock Testing
Hi, Jim Shaw here again at Crystal Group. I wanted to talk a little bit about MIL S 901 testing, that’s a shock test. It’s kind of specific to the Navy. This particular test is one that is invoked on us and we actually outsource the testing. But it’s kind of a neat test that we do. And there is essentially three categories of MIL S 901D testing. There’s a light hammer blow, there’s a medium hammer blow and then there’s the barge test or the heavy.
Light is a 400 lbs. hammer, the medium is a 3,000 lbs. hammer and the heavy test is just crazy. Essentially of the classes in that testing, there’s three different classes. There’s Class I, Class II and Class III. Class I is essentially hard mounted to the deck. And that’s in essence you have an entire system that comes in and is mounted into the deck and tested. Then there is isolated, that’s Class II. And isolated is where you have rope isolators or whatever you need to on the bottom of the racks so that you can than isolate the system.
And Class III is essentially both, so it qualifies as being both hard mounted and isolated. Within those tests there is a Grade A and there’s a Grade B type of test. Grade A’s are mission critical tests, where Grade B is don’t fly out and hurt someone. So essentially they are making sure the equipment is attached. There are three different types within the testing, there’s type A, B and C. Type A is essentially the actual structure that you’re testing that’s going to be put on the ship.
Type B is a component of that structure that you are going to put on the ship. Type C is essentially components of components. So this is a very difficult test for anyone to pass and in essence it emulates the ship getting hit by a torpedo, or a destroyer being hit by some sort of underwater armament or explosive device. That is a little bit about MIL-S-901D testing.