Launch Pad Water Deluge System - The System That Keeps You And Rockets Safe.

The sound suppression system in action. [Interesting Engineering]

Have you ever noticed the white cloud which rises upwards when the rocket engines fire. No, its not smoke or the exhaust of the rocket but water vapor. What! Why! How! I know it sounds faulty but its true. The water vapor is due to the pad deluge system used in almost every launchpad. This system is used to protect the rocket and the surroundings from the intense noise and vibrations produced just before liftoff to attend maximum thrust at the pad. Water stored in a 290-foot-high, 300,000 gallon tank on the northeast side of the pad is released just prior to the main engine ignition and flows by gravity to special outlets on the platform, including six 12-foot-high quench nozzles, or "rainbirds." Nine seconds after liftoff, peak flow rate is 900,000 gallons per minute. The system reduces acoustical levels within the orbiter payload bay to about 142 decibels, below the design requirement of 145 decibels. Wow , that's loud. 150 decibels is usually considered enough to burst your eardrums, but the threshold for death is usually pegged at around 185-200 dB. A passenger car driving by at 25 feet is about 60 dB, being next to a jackhammer or lawn mower is around 100 dB, a nearby chainsaw is 120 dB. If this system fails during engine ignition , the extremely loud sound starts to vibrate the rocket , bouncing off the pad. This will cause fuel leaks as super-cooled propellants are very hard to contain especially liquid hydrogen. This will make the expensive rocket blow up , putting up a spectacular fireworks show. Not only this can obliterate the payload or the stuff the rocket needs to carry to space [Satellites,etc] it will also destroy the launchpad which won't come in action until serous refurbishment. Remember that I told that ALMOST all rocket launchpads use this technology? The Soviets designed launchpad in a different way: the launchpad is above a large hole. So there is much more space for exhaust from rocket, and they are mostly deflected outside. In such manner, the acoustic pressure is a lot lower on the rocket (and the rocket will leave launchpad soon, so really not a huge problem). Soyuz may not be so large, but N1, Proton, and Energia were/are a lot larger, comparable to Saturn V and Space Shuttle.Launchpad in Florida cannot have such huge hole (they are at sea level, a lot of rain, and soil structure cannot support big holes. So NASA used water system to reduce the acoustic pressure. Even ESA's [European Space Agency] Ariane 5 rocket's launchpad uses this hole for sound suppression.So the next time you hear " Firing chain is armed , sound suppression water system activated " and you happened to see the launch up close, be thankful to this system and without them you would be dead before you know it.

Don't forget to subscribe to my blog and you can visit my YouTube channel and the link's in my homepage.

The 300,000 gallon Sound Suppression Tank. [Lazy Toad Ranch]