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Willemstan I-SHAT System

Infrastructure for Severe Harm Alert Technology

This article was last updated on: Semptember 26th 2022

Image at the top of the screen.

Charlie Nolan's dog just chilling as the SHART-1 goes off.

"I don't know I just like building big powerful things that are borderline illegal."

- Charlie Nolan in the Willemstan documentary on the SHART series.


The Willemstan I-SHAT system (Infrastructure for Severe Harm Alert Technology) is a concept that has been used in many countries- a centralized way to send important messages to civilians. This includes things like civil defense sirens, radio broadcasts, and phone notifications. This can notify citizens about emergencies or other important news. The I-SHAT system currently includes Willemstan Government Alerts and the SHART sirens. It used to be integrated with the Live Camera Feed livestreams. The I-SHAT system is now partially automated, and is integrated with the SuS Bot and a local weather station. When it detects severe weather (such as high winds) a notification is sent to the operator of the SHART siren who can decide if the weather is worthy of sounding a signal indicating danger.

The SHART Series

The SHART series is a series of electronic civil defense sirens. Development on the SHART sirens began in early June, with building and tests of an early model, the SHART-1. The SHART (Severe Harm Alert Repeater Tower) series are electronic civil defense sirens, capable of battery backup, solar power, and their own tone generation, and are able to drive up to 160 watts of speaker output. The current version uses an 80 watt output. The SHART series generate their tones and provide an interface to the operator with an Arduino Uno, and drive speaker output through digital-logic H-bridge motor controllers. They get power from a 12 volt car battery. The SHART sirens are able to effectively double their output power by outputting an AC square wave signal to the speaker. Recent iterations of the SHART are weatherproof. Since early August, the unit has not been running daily tests due to fear of noise complaint, but will still be activated for monthly tests, around the same time as the county (1 PM on the first Saturday of each month). The most recent long-distance test confirmed that the siren is clearly audible at over 1,100 feet. The current SHART siren is capable of 17 signals in total, with customizable tone pitches and it is the only digital siren controller that mimics analog/electromechanical siren characteristics. If it were produced commercially, it would technically be the most versatile outdoor warning siren tone generator on the market, as no current siren controllers have 17 signals, support dual-tone, or analog-type windup sounds. The controller is also extremely efficient, by using digital-logic amplifiers, with no ambient power leakage, and very low standby power usage for the whole unit. The design and function of the SHART series was inspired by the analog Whelen sirens of the 1980s and Federal Signal's EOWS series, and the sounds were inspired by analog and digital Whelen siren controllers (such as the ESC-864), and electro-mechanical Federal Signal sirens of the 1960s to 1990s (such as the 3T22). The naming scheme is decided by the number of the major version, followed by the letter of the minor revision, followed by the maximum wattage delivered to the speakers.

SHART-1 Series

Prototypes, not meant for prolonged outdoor use. In videos, the output speaker is mounted on a few garden stakes. The SHART-1 used a 60 watt car speaker for its output, outputting about 45 watts.

The SHART-1, in the flesh.

SHART-2 Series

The SHART-2 series used a new naming scheme. The 2 means it is a member of the SHART-2 series and the letter means the revision. The following numbers are maximum output wattage. The 2 series was more than an early prototype. The 2 series stayed outside exposed to the weather, as a test of reliability. The notable issues include dysfunctional daily testing until revision E, and the PA function failing to work throughout the entire lineup of prototypes.

The SHART-2D56.

SHART 3 Series

The 3 series used new speaker drivers, with an increased theoretical maximum output of 110.8 dB at 100 feet, and a calculated typical output of 109.4 dB at 100 feet, similar to that of some real civil defense sirens. Although this is output assumed in a best acse scenario weather-wise and scene-wise. It has been tested to be above ambient noise level at over 700 feet (originally incorrectly reported as 1000 feet).

The SHART 3A56. The speakers are visible but the control housing is not.

SHART 4 Series

The 3B56 died an unfortunate death after filling with water some time between September 7th and September 9th of 2020. The audio amplifier and battery regulator were ruined and it was clear the SHART 3B56 was not waterproof. It was also horrifyingly filthy inside, and a large number of dead bugs and even a dead earthworm were found in the control housing. It can be determined that this was quite the bacteria brewery. Some electronics also had terrible corrosion. These and previous versions of the SHART also had problems such as low serviceability and very limited controls, which the 4th major increment of the SHART hoped to solve. It was also decided that a mount, increased and regulated speaker output, and smarter power usage would be some goals for the project. So it was decided that major overhauls had to be made for the SHART 4 Series.

The SHART 4B80. Notice the separated battery housing (below) and circuit housing (on wooden beam) containers. It is also apparent that the wood used in construction of the unit became extremely warped.

S5 Series

Planning of the SHART 5 began in December of 2020, after the SHART 4 proved unreliable in cold weather, and the output could not even travel half a mile.

The Death of SHART

In the summer of 2022, after several months of storage, the siren fell over and the speaker mounts broke. A few days later, it was officially decomissioned and deconstructed. However, plans are in the works for a whole new generation, one which would be feasible to sell to municipalities...

Severe Harm Alert Repeater Tower Testing

Here is a list of all of the videotaped tests for each SHART model, as well as the result. You can find all of the tests in a playlist on the Silly Goose YouTube channel. The testing procedure is not very constant, but usually the siren will run on the first Saturday of the month, between the hours of 12 and 3 PM, for 1 minute. This procedure may change, as FEMA guidelines suggest testing all outdoor warning sirens that exceed 123 dB at least once per month in a 1 minute steady signal, and a 1 minute wail signal.









SHART 4 prototypes



S5 Prototype