A modern version of a World War II air raid siren has been promoted by a Wellington engineering company as offering the real answer to Tauranga's tsunami warning problem.
Tactical Tooling has raised doubts about the efficiency of electronic hooter sirens that are on the council's shortlist for Tauranga's vulnerable low-lying suburbs.
The criticism follows uncertainty around the recent test of an electronic alarm in Papamoa, with Tauranga City councillor Bill Grainger saying he was still a supporter of the distinctive sirens of WWII.
Tactical Tooling design engineer Gary Lewis said the company originally designed electronic hooter systems but quickly discovered that, due to simple laws of physics, they were doomed to failure as they could never be entirely successful at long distances.
The company put in an unsuccessful tender for the council's contract but Mr Lewis said he did not want his comments to sound like sour grapes.
After striking difficulties with electronic sirens, Tactical Tooling looked at the physics of a traditional war siren and discovered that it had a unique ability to generate a shock wave that had the same shape as thunder or a boom from a supersonic aircraft. The company redesigned the air raid siren and increased its reach in still weather from 8km to 32km.
It meant they could achieve total coverage of Tauranga using six sirens at $10,000 each and an estimated total system cost of $100,000 with installation. He said that would bring down costs astronomically.
Mr Lewis said he was told at a council tendering presentation that their knowledge of the Resource Management Act was poor.
"By demanding RMA expertise and installation requirements, the Tauranga City Council had effectively locked out suppliers of better equipment."
He said the spirit of the RMA was surely not to kill people by preventing the installation of life-saving emergency equipment.
Mr Lewis' comments followed the test of one of the two shortlisted sirens which Papamoa Progressive Association chairman Steve Morris failed to hear, even although he was listening out for it.
Mr Morris was in the Papamoa Library during the test on June 1 and said that neither he nor the library staff heard anything.
His wife also did not hear the siren and she was just outside the area of loudest noise.
City councillor Bill Grainger shared Mr Lewis' enthusiasm for siren technologies that dated back more than 70 years.
"You can hear them. When a tsunami is coming in, what do people want? They want to hear something, no matter how loud it is. They have proved themselves."
Council planning engineer Barry Somers said the council worked with an acoustic engineer in the evaluation of the tenders and the claims of Tactical Tooling were not ignored by the engineer.
He could not comment further because the council was in a competitive tendering process.
Mr Somers said the council had gone to the market asking people to tender on a total design, consent and build process.
He said Tactical Tooling's tender had been for a siren in a box and it would have been up to the council to design the network of sirens, work on the communication protocols, consent the sirens and mount them.
"It was a very minimal proposal ... we were looking for a total package."
The bulk of the tenderers included everything that the council asked for, he said.
A report on the Papamoa siren test including an acoustic engineer's assessment and public feedback will be reported back to the council.