PLEASANTON -- A long lost siren song of the city's past called out Friday for the first time in nearly three decades.

The 1923 volunteer firefighter siren had been misplaced, hiding in plain sight, left unused and neglected on a pole on a private downtown lot, but Pleasanton has restored the relic for a new life.

Faded and choked with wasps until a month ago, the rediscovered siren will soon be on display in a fire station or other public building and trucked out for occasional short trips to sound off at public events.

The 82-year-old son of the siren maker was on hand Friday to reactivate the siren in a short noon ceremony to re-christen and test the refurbished relic.

Harry W. Heath, center, the son of Harry C. Heath, the original maker of the old civil defense siren, with his nephew Marvin Schmidt, right, look over the
Harry W. Heath, center, the son of Harry C. Heath, the original maker of the old civil defense siren, with his nephew Marvin Schmidt, right, look over the newly restored siren at the city of Pleasanton's corporation yard on Dec. 6, 2013. Chris Rizzoli, city support services supervisor, who headed the restoration, invited Heath and his family to hear the siren after it was restored. (Laura A. Oda/Staff)

"It's exciting to be here as Pleasanton re-connects with this part of its past," said Harry W. Heath, a Tiburon resident. "There were many small towns across America that used sirens like this."

A similar Heath siren used at San Francisco's Ferry Building for decades is on display at the San Francisco Maritime Museum.

"There aren't many still around," Heath said. "I was very surprised when I got a call that Pleasanton had one."

In 1923, Pleasanton replaced its fire bells with the louder, shriller and stronger Heath siren to call in the grain growers, dairy farmers, auto mechanics and other volunteers to fight fires.

The siren also blared for air raid drills during World War II and duck-and-cover civil defense drills during the Cold War, said Chris Rizzoli, support services supervisor with Pleasanton's public works department.

Pleasanton's switch to full-time firefighters in the 1970s made the siren obsolete, and it was moved in the 1980s to a less prominent location on land owned by an assistant fire chief, Rizzoli said.

Then it was forgotten until a business owner complained he was worried the 300-pound monster might topple down on someone's head.

"We took it down, but didn't really know what we had at first," Rizzoli said.

It took some sleuthing by Rizzoli and the city clerk to unearth the device's history.

Maintenance crews cleaned out the wasps, repainted the siren, and did other work to get it in shape.

On Friday, city workers looked on as Heath flipped the switch and the siren screeched its best for a few seconds.

"We're big on history in Pleasanton," Rizzoli said Friday, "and this is a relic we want to preserve."

The city had considered sounding the siren to begin a holiday parade Saturday afternoon, but decided against it because of limited time to alert neighbors.

Rizzoli said a search of city records also found another surprise -- that in 1918 the city received a six-pound howitzer from a Benicia arsenal -- apparently to fire off blanks in ceremonies.

"I wonder where that six-pound howitzer is ...," he said.

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff.