Low Head Fog Alarm | The Low Head Fog Horn | Hear the Alarm

The Sound is Found:-     Writer: Dace Shugg     Photographer: Alan Moyle     Published in: 40°SOUTH Tasmania, issue 24     Website: www.fortysouth.com.au

The dangerous Hebe Reef lies at the mouth of the Tamar River (at 40° South), the gateway to northern Tasmania. Navigating the narrow entrance to the river presents a real navigational challenge.
    Shortly after the first European settlement at George Town in 1804, a fire beacon lit by whale oil was erected at Low Head on the eastern side of the Tamar Heads. The present lighthouse was built in 1888 and remains operational.
    The area is prone to heavy sea and river fogs. Accordingly a fog alarm was installed at the Light Station in 1929. The type "G" Diaphone Fog Alarm with its unique signal, manufactured by Chance Bros in Birmingham, UK, was shipped to Tasmania, installed and operated continually from 1929 until 1973. Tamar Heads have been a popular holiday area for many years and the "groan-grunt" of the fog alarm, which could be heard at distances of up to 30 kilometres from Low Head, was part of holiday life in the region.
    It was not the absence of the fog warning, however, that caused the grounding in July 1995 of the Iron
Baron on Hebe Reef. The ensuing oil spill was a potential ecological disaster and the massive clean-up effort mobilised the entire local community.
In gratitude, corporate giant (the then) BHP provided some of the funds needed to carry out renovations to the old Low Head Pilot Station.
    This collective activity stimulated a renewal of interest in another historical maritime installation in the area, the silent fog alarm locked away in its shed for 28 years. Early in 2000, a couple of locals from the Low Head Progress & Heritage Association and a ranger from the Parks & Wildlife Service inspected the installation through a murky window of the padlocked shed and decided to refurbish the fog alarm.
    This sounds simple, but the story of what it took to reawaken it is a tale of amazing tenacity. To start with, no one knew where the key was held, so after weeks of fruitless phone calls, the 'universal key' -bolt cutters -was used to gain entry. The first revelation was that the entire installation had been lavishly coated with green paint to preserve it from the elements. The installation in fact consisted of machinery designed to provide compressed air and a timing mechanism to operate the sounding valves.


    The equipment certainly looked well preserved, but since the condition of the internal parts was unknown, it was thought essential to obtain operating manuals and engineering drawings before attempting to test the alarm.
    After months of unrewarding enquiries, contact was made through the Internet with the senior maintenance engineer at the British Lighthouse Service in Penzance. The engineer eventually found the necessary manuals in a disused shed at the Portland Bill Light Station on England's south coast. He e-mailed back: " It is imperative that no attempt is made to put air into the unit until it is clear that the piston is free in the cylinder!" The local team was immensely relieved that they had restrained themselves, considering the potential danger. They were also thrilled to learn that the Low Head Diaphone was the only one of its kind in the world that, potentially, could be made operational.
    The equipment was taken apart and all components thoroughly inspected. It looked very promising; the system had been beautifully designed and precision-engineered and the internal parts appeared to be in perfect order. However; there were minor corrosion problems caused by rainwater. A local George Town engineer, who had considerable experience with pressure vessels, advised that it would be possible to carry out small repairs which he believed would satisfy the inspection authorities and allow the pressure vessels to be fully certified.
    With support from the Parks & Wildlife Service, a specialist welder was engaged to undertake these repairs. The pressure vessels were then tested and certified. During this period all the components of the compressors, timing equipment, operating and sounding valves and the Diaphone were cleaned and reassembled in accordance with the instructions received from the UK. All was ready for the final test.
    The electric compressor was started up, pressure vessels brought to operating pressure, control valves opened and the timing motor started. Seconds later the magnificent roar of a thousand elephants echoed through the area.
    The sound was found!

Low Head Fog Alarm | The Low Head Fog Horn | Hear the Alarm