Diaphone
Encyclopedia
For Diaphone, the Noctuid moth species see Diaphone (moth)
The diaphone was a noisemaking device best known for its use as a foghorn
: it could produce deep, powerful tones able to carry a long distance. Diaphones were also used at some fire station
s and in other situations where a loud audible signal was required.
of the same name invented by Robert Hope-Jones
, creator of the Wurlitzer
organ. Hope-Jones' design, based on the vibrations in air created by a slotted piston
moving within a correspondingly slotted cylinder, was adapted and patented by Professor John Pell Northey of the University of Toronto
, who added a secondary compressed air
supply to the piston to power it on both forward and reverse strokes and create an even more powerful sound. The entire horn apparatus was driven by a compressor
.
To manufacture the new equipment, Northey set up the Diaphone Signal Co. at Toronto
in 1903. It manufactured a range of diaphone models: the large "Type F", which created a tone of about 250 hertz
, found worldwide use as a fog signal, especially in lighthouses. The mechanism of the diaphone created a noticeable low-frequency "grunt" at the end of each note produced, caused by the speed of the piston reducing as the air supply was cut. As this low-frequency sound could carry further, Northey's son Rodney redesigned the "Type F" model to sustain the second low tone, creating the familiar two-tone fog signal which was commonly used in lighthouses and lightvessel
s in the United States
and Canada
(as well as in a famous series of radio commercials for Lifebuoy soap
). Installations in Europe generally used single-tone diaphones.
Rodney Northey sold the Diaphone Signal Co. in 1932, when it was bought by a Buffalo, NY company, Deck Brothers, working under contract for the United States Lighthouse Service
. This company still exists, although it no longer manufactures diaphones. The European manufacturing rights were obtained by Chance Brothers
of Birmingham
in the United Kingdom
, already a major supplier of Fresnel lens
es and other equipment to lighthouse authorities.
The majority of diaphone installations were removed or became disused when lighthouses were automated during the 1960s and 1970s, though a few survive in working condition in lighthouses around the world.
and the public during emergencies. Many Gamewell diaphone systems remain in use today. The Gamewell diaphone has a range of about six miles under optimum conditions.
Diaphone (moth)
Diaphone is a genus of moths of the Noctuidae family.-Species:* Diaphone delamarei Viette, 1962* Diaphone eumela * Diaphone lampra Karsch, 1894* Diaphone niveiplaga Carcasson, 1965* Diaphone rungsi Laporte, 1973...
The diaphone was a noisemaking device best known for its use as a foghorn
Foghorn
A foghorn or fog signal or fog bell is a device that uses sound to warn vehicles of hazards or boats of the presence of other vehicles in foggy conditions. The term is most often used in relation to marine transport...
: it could produce deep, powerful tones able to carry a long distance. Diaphones were also used at some fire station
Fire station
A fire station is a structure or other area set aside for storage of firefighting apparatus , personal protective equipment, fire hose, fire extinguishers, and other fire extinguishing equipment...
s and in other situations where a loud audible signal was required.
History
The diaphone horn was based directly on the organ stopOrgan stop
An organ stop is a component of a pipe organ that admits pressurized air to a set of organ pipes. Its name comes from the fact that stops can be used selectively by the organist; some can be "on" , while others can be "off" .The term can also refer...
of the same name invented by Robert Hope-Jones
Robert Hope-Jones
Robert Hope-Jones , is considered to be the inventor of the theatre organ in the early 20th century...
, creator of the Wurlitzer
Wurlitzer
The Rudolph Wurlitzer Company, usually referred to simply as Wurlitzer, was an American company that produced stringed instruments, woodwinds, brass instruments, theatre organs, band organs, orchestrions, electronic organs, electric pianos and jukeboxes....
organ. Hope-Jones' design, based on the vibrations in air created by a slotted piston
Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from...
moving within a correspondingly slotted cylinder, was adapted and patented by Professor John Pell Northey of the University of Toronto
University of Toronto
The University of Toronto is a public research university in Toronto, Ontario, Canada, situated on the grounds that surround Queen's Park. It was founded by royal charter in 1827 as King's College, the first institution of higher learning in Upper Canada...
, who added a secondary compressed air
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....
supply to the piston to power it on both forward and reverse strokes and create an even more powerful sound. The entire horn apparatus was driven by a compressor
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...
.
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...
in 1903. It manufactured a range of diaphone models: the large "Type F", which created a tone of about 250 hertz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
, found worldwide use as a fog signal, especially in lighthouses. The mechanism of the diaphone created a noticeable low-frequency "grunt" at the end of each note produced, caused by the speed of the piston reducing as the air supply was cut. As this low-frequency sound could carry further, Northey's son Rodney redesigned the "Type F" model to sustain the second low tone, creating the familiar two-tone fog signal which was commonly used in lighthouses and lightvessel
Lightvessel
A lightvessel, or lightship, is a ship which acts as a lighthouse. They are used in waters that are too deep or otherwise unsuitable for lighthouse construction...
s in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
(as well as in a famous series of radio commercials for Lifebuoy soap
Lifebuoy (soap)
Lifebuoy is a brand of soap containing phenol marketed originally by Lever Brothers in England in 1895.-History:Although Lifebuoy is no longer produced in the US and UK, it is still being mass produced by Unilever in Cyprus for the UK, EU, US and Brazil markets, as well as in Trinidad and Tobago...
). Installations in Europe generally used single-tone diaphones.
United States Lighthouse Service
The United States Lighthouse Service, also known as the Bureau of Lighthouses, was the agency of the US Federal Government that was responsible for the upkeep and maintenance of all lighthouses in the United States from the time of its creation in 1910 until 1939...
. This company still exists, although it no longer manufactures diaphones. The European manufacturing rights were obtained by Chance Brothers
Chance Brothers
Chance Brothers and Company was a glassworks originally based in Spon Lane, Smethwick, West Midlands , in England. It was a leading glass manufacturer and a pioneer of British glassmaking technology....
of Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, already a major supplier of Fresnel lens
Fresnel lens
A Fresnel lens is a type of lens originally developed by French physicist Augustin-Jean Fresnel for lighthouses.The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design...
es and other equipment to lighthouse authorities.
The majority of diaphone installations were removed or became disused when lighthouses were automated during the 1960s and 1970s, though a few survive in working condition in lighthouses around the world.
The Gamewell Diaphone
This considerably smaller device was produced by the Gamewell Corporation, of Newton, Mass, for use as a municipal alarm, especially at fire stations, to alert firemenFirefighter
Firefighters are rescuers extensively trained primarily to put out hazardous fires that threaten civilian populations and property, to rescue people from car incidents, collapsed and burning buildings and other such situations...
and the public during emergencies. Many Gamewell diaphone systems remain in use today. The Gamewell diaphone has a range of about six miles under optimum conditions.
Working diaphone installations
The following installations are still functional and are demonstrated from time to time as tourist attractions.- Duluth South Breakwater Lighthouse, Duluth (MN): the F-2-T (two-tone) diaphones at this lighthouse were reinstated after a campaign by residents, and reactivated in 1995.
- East Brother Light Station, Richmond, CA
- Grand Traverse LighthouseGrand Traverse LighthouseGrand Traverse Light is a lighthouse in the U.S. state of Michigan, located at the tip of the Leelanau Peninsula, which separates Lake Michigan and Grand Traverse Bay. It marks the Manitou passage, where Lake Michigan elides into Grand Traverse Bay. In 1858, the present light was built, replacing a...
, MichiganMichiganMichigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake".... - Portland Bill Lighthouse, Isle of PortlandIsle of PortlandThe Isle of Portland is a limestone tied island, long by wide, in the English Channel. Portland is south of the resort of Weymouth, forming the southernmost point of the county of Dorset, England. A tombolo over which runs the A354 road connects it to Chesil Beach and the mainland. Portland and...
, United KingdomUnited KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
: A Type F diaphone decommissioned in 1996, but restored in 2003 for the benefit of visitors. - Low Head LighthouseLow Head LighthouseLow Head Lighthouse is located in Low Head, Tasmania, about north of George Town on the east side of the mouth of the Tamar River. It was the third lighthouse to be constructed in Australia, and it is also Australia's oldest continuously used pilot station...
in Low Head, TasmaniaLow Head, TasmaniaLow Head is a small hamlet located on a peninsula by the same name 5 km north-west of George Town, Tasmania, Australia. On the mouth of the Tamar River. It is known for its diving off the Low Head Pilots Station. The town has a lighthouse, a beach and a penguin colony...
possesses the only working Type G diaphone (one of the largest models constructed) in the world. It has a range of up to 20 miles.