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When is a chunk of concrete more than just a chunk of concrete?

Updated: Mar 22

You probably rarely think about the testing everyday products go through to ensure they can withstand the shake, rattle, and roll of transportation and use. How does your favorite vineyard package bottles of wine for safe transportation to your store shelves? How does a car manufacturer know their pickup trucks will survive bumpy roads and potholes?

Chances are, these and most of the other products you use every day were tested on a vibration or slip table system consisting of that chunk of concrete, called a reaction mass, attached to a steel table.  During testing, the table shakes the test item to simulate real-world conditions.

More technical, complex, and even explosive items like satellites, missiles, and ordinance also undergo testing on vibration shakers. This vital testing can answer actual life-or-death questions, such as

  • How will a satellite react to being launched into space or a missile react to being strapped under the wing of a fighter jet?

  • Can a piece of equipment in a submarine survive the “push-pull” impact of a depth charge exploding nearby?

  • Can a space capsule withstand the sound pressure and dynamic forces it would be subject to if the Launch Escape System needs to pull it to safety during a catastrophic launch failure? 

Ross Group has a long history of involvement with these types of projects. Our engineering division and its team members have worked on vibration testing and acoustic testing projects of various sizes in North America, South Korea, the United Kingdom, Israel, and Germany, including the world’s highest capacity and most powerful spacecraft shaker system! NASA’s Reverberant Acoustic Test Facility (RATF) and Mechanical Vibration Facility (MVF) is a spacecraft acoustic test chamber with a concrete base measuring 50’x50’ around and 19’ thick. With the capacity to simulate the noise of a spacecraft launch up to 163 decibels (as loud as the thrust of 20 jet engines), the RATF in conjunction with the MVF subjects test articles to the rigorous conditions of launch. Check out the full system at this video from the NASA Plum Brook (now Neil A Armstrong) Test Facility.

In addition to designing reaction masses for vibration testing equipment, Ross Group has completed turnkey projects such as a Progressive Wave Tube now being installed for the US Navy at China Lake Naval Weapons Station in CA.  This once-in-a-generation piece of equipment will generate 174 dB of sound pressure for testing components. How loud is this? Well, consider that decibel levels ranging from 120 to 140 dB can rupture eardrums, lead to instant hearing loss, and cause pain. Sounds in this range include aircraft taking off, jackhammers and chainsaws, and gunshots from high-caliber firearms. While 174dB doesn’t seem that much higher, remember that the decibel scale is logarithmic - the sound pressure doubles about every three decibels! 

As you can see, vibration testing systems play an important behind-the-scenes role in many areas of our lives, from wine packaging to spacecraft launches. Ross Group is proud to have been part of designing and installing some of these very special “chunks of concrete.” Next time you sit down to sip some wine and watch the latest Space-X launch, consider that the folks at Ross Group may well have played a part in the success of both the wine and the launch.

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