What is the MIL-DTL-901E?
MIL-DTL-901E is a detail specification defining the high-impact shock testing requirements for machinery, equipment, systems, and structures aboard surface ships and submarines. Adopted 20 June 2017, MIL-DTL-910E supersedes MIL-S-910D as the standard for verifying the ability of shipboard installations to withstand the shock of nuclear and conventional weapons, as well as environmental mechanical shock during operation.
What is the difference between MIL-DTL-901E and MIL-S-901D?
MIL-DTL-901E, like its MIL-S-901D predecessor, is designed to help ensure the survivability and availability of critical shipboard systems under normal operating conditions, as well as when in combat or while under attack.
MIL-S-901D had been the de facto standard for shock testing and qualification of maritime systems, including mission- and safety-critical computer systems and electronic equipment, for nearly 30 years. The 82-page MIL-S-901D document, composed on a typewriter and published on 17 March 1989, described the functional requirements for a system, including its capabilities and the environment in which it must operate, and the criteria for verifying compliance, but it provided flexibility in how required results were achieved.
MIL-DTL-901E goes beyond MIL-S-901D with the addition of detailed production and testing procedures, extensive diagrams and examples, and provisions for testing on land to help field needed equipment faster and more cost-effectively.
What do I need to know about MIL-DTL-901E?
Mission- and safety-critical systems should be built, tested, and proven to work reliably, especially in harsh or combat environments. To help ensure the survivability and reliability of shipboard systems, MIL-S-901D has been updated, expanded, and revised into a detail specification, which are intended to limit ambiguity or uncertainty.
MIL-DTL-901E standard shock test methods include: lightweight and medium weight shock machine tests, the heavyweight shock test performed on a floating shock platform, and medium weight deck simulating shock test on deck-mounted equipment or deck simulating shock machine (DSSM).
The detail specification classifies items under test into one of two shock grade categories. Grade A is applicable to items that are essential to the safety and continued combat capability of the ship. Grade B applies to items that are not essential to the safety and combat capability of the ship, but which could become a hazard to personnel or to the ship as a whole as a result of exposure to shock.
MIL-DTL-910E further categorize items to be tested by type – as a principal unit, subsidiary component, or subassembly – and equipment class. Tests are then classified according to the item type: a Type A test applies to a principal unit, Type B test to a subsidiary component, and Type C test to a subassembly.
How do I ensure equipment is compliant to MIL-S-901D or MIL-DTL-901E?
When evaluating solutions for mission- and safety-critical applications, look for products that are specifically designed to be rugged and reliable. Crystal Group products are meticulously engineered, manufactured, and assembled specifically to withstand challenging applications, harsh elements, and extreme environments. (Take a closer look at how Crystal Group builds rugged products, from material selection through parts stabilization during assembly, thermal management, and more.)
It is always advisable to confirm that a particular solution complies with MIL-S-901D or, preferably, the more detailed MIL-DTL-901E before investing in and fielding it. Verify the test methods and test parameters used, and whether an internal or independent test facility was employed. (Read more about common standards and requirements, which Crystal Group products are designed to meet or exceed.)