With two-way communication, technicians can more efficiently track and address maintenance issues as they arise. The sirens are solar powered and each use four deep-cycle batteries. Technicians can now be miles away and check items such as battery voltage, whether the charger is working and even receive notifications from the siren if someone tries to break into it.
“I would say our sirens are in much better condition now based on the information we’ve been able to get through the system and the [technicians] having time to go out and fix them,” Simon said.
The satellite-cellular connection also lets the state test the system without disturbing residents. Simon said “quiet tests” can be conducted during which the siren is given instructions to activate at a frequency that’s too high for anyone to hear, but give the state a reading on the amplifiers’ output. Once complete, the results can be reviewed to determine if the sirens are working properly.
“In the few months we’ve had this working on Oahu, we’ve found this additional information has really helped the technicians go out and get more of the sirens fixed more quickly,” Simon said. “They’re working almost immediately after we find a problem, instead of not knowing.”
While the installation process went fairly well on Oahu, there were some expected bumps along the way. Since the control system was completely new, there was a bit of a learning curve as technicians became familiar with operating it. Federal Signal also had to tweak the system to address minor connectivity issues.
Since the sirens use satellite signals as their primary source of communication, the area around the sirens must be clear of vegetation. That can be a problem in Hawaii. Simon explained that because there’s a lot of rain throughout the islands, certain locations can experience rapid overgrowth.
Although that typically doesn’t affect cellular communications, it can interfere with satellite coverage. So existing siren sites had to be evaluated, and when looking into new locations, officials had to factor vegetation into consideration.
In addition, using satellite communication causes a delay from the time the siren is activated by state personnel until it actually goes off. The state synchronizes its monthly test of the siren system with a radio broadcast. But once the siren is activated, it takes 30 to 45 seconds before it sounds, which could be confusing to the average resident.
The delay shouldn’t matter during an actual emergency, however. Since disasters are usually unexpected, people wouldn’t know when the button was pushed, so an extra 30 to 45 seconds before the siren starts would likely have a negligible impact on safety.
The U.S. military has also taken note of Hawaii’s siren upgrade. The Army, Navy, Air Force and Marines all have bases in Hawaii and depending on the branch, either work in conjunction with the state to issue emergency warnings or use their own system.
Simon said Joint Base Pearl Harbor-Hickam has its own radio control system, but one of the siren sites activates automatically off the state’s signal. The Army, he said, is in the process of doing something similar.
Photo courtesy of Adam DuBrowa/FEMA. This story was originally published by Emergency Management magazine.