Using a little ingenuity, workers with Hawaii County Civil Defense and Hawaii Police Department managed to avoid a technical problem that might have resulted in the failure of multiple tsunami sirens during Monday’s monthly test.
Before each test is conducted, explained Civil Defense Director Darryl Oliveira, workers do a test run of the radio signals which are used to relay commands to Hawaii Island’s 71 sirens. During that test, the police radio crew discovered that the Kulani Cone repeater site, one of 13 on the island, was malfunctioning. Located southeast of the Kulani Prison, the repeater relays messages to farflung sirens including ones in Hilo, Keaukaha and Puna.
“We use a microwave network to relay signals to the sirens, and for some reason the equipment at Kulani Cone wasn’t working,” Oliveira said. “It’s a pretty remote site, and the radio crew knew they wouldn’t be able to get out to it before the (11:45 a.m.) test.”
Instead, the crew worked to create a new route for the radio signals using portable radio equipment.
“It’s a method we think we’ll be able to use in the future if this happens again,” he added. “At least, until we’ve completed our upgrades.”
Hawaii Civil Defense is in the midst of a $25.6 million siren modernization program that would make the sirens more reliable. Each siren on the island would be upgraded to receive a new activation system that relies on cellular and satellite networks rather than radio transmissions. The siren upgrade project would also increase the number of sirens on island from 71 to 124.
The upgrades are badly needed, as siren failures have become a regular event during activations. During Monday’s test, a total of four sirens failed, including one in Kona, one in Upchurch, one in Nanawale and one in Paukaa. Each of the failures were unrelated to the radio transmission problems experienced at Kulani Cone, Oliveira said.
During a test in July, as many as 18 sirens failed. Those failures were linked to a malfunction of the Kulani Cone repeater site, with sirens failing throughout Hilo and Puna.
Before that, a total of 13 sirens failed on the evening of Oct. 27, 2012, when a tsunami warning was issued following a magnitude-7.7 earthquake off of Canada’s Pacific Coast. The warning was issued at 7:09 p.m., but sirens in some areas of East Hawaii didn’t sound until two hours later.
Email Colin M. Stewart at cstewart@hawaiitribune-herald.com.