Every Tornado Siren In Dallas Hacked

Someone had some fun with the Dallas early warning tornado siren system on Friday, April 8th. All 156 tornado sirens were hacked to go off just before midnight until they were manually turned off individually, reports The Washington Post. Thousands of residents flooded 911 call centers asking if they were under attack, if there was a tornado or if the zombie apocalypse had begun. The sirens were blaring for at least an hour and was originally put down as a malfunction, however it was later revealed that it was a hack and the “hacker” must have had physical access to the siren control center.

This isn’t the first time Dallas has had problems with “hackers” breaking into their infrastructure, Only last year some unknown person/persons hacked electronic road signs (a prank we’ve seen before) in and around Dallas claiming “Work is Canceled — Go Back Home” and “Donald Trump Is A Shape-shifting Lizard!!”. Mayor Mike Rawlings claims the perpetrators will be found and prosecuted although we don’t share his confidence since last year’s attackers are still at large.

The video below is one of many on YouTube filmed by bemused Dallas residents.

UPDATE: This hack seems to have been accomplished via DTMF signals broadcast on radio frequency in the clear. Recognizing the vulnerability after the fact, the system is now using some form of encryption for the control messages. Thanks [Dan J.] for posting this in the comments below.

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Building a wooden air raid siren

siren

A while back, [Matthias] was working on a dust collector for his shop. Being the master woodsmith he is, he decided to build a dust collection system out of wood. Everything worked out in the end, but in creating wooden impellers and blowers, he discovered his creations made a lot of noise. For this project, instead of trying to quiet his blower, he decided to make one as loud as possible in the form of an air raid siren.

The basic idea behind [Matthias]’ air raid siren is to make two impellers that force air through two stators along the perimeter of the rotor. As the siren spins, the air coming from the impellers is either blocked or passes through the stators, creating an alternating high and low pressure; to be more accurate, it creates a ton of noise. Stack two of these impellers together and you’ve got a two-tone air raid siren made out of wood.

For something that’s spinning very fast, we’re surprised [Matthias] didn’t have more problems with balancing his siren than he did. There are a few useful tricks to be picked up from his tutorial, though: balancing everything on a marble really seemed to help with the build.

As for how loud the siren is, [Matthias] can’t give us a decibel volume. From the video after the break, though, we can tell you it’s really, really loud.

Thanks [Dimitar] for sending this in. [Matthias], it’s alright if you send projects in yourself. You’ve earned the right to say, “I am so cool!”

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