Method of communication between diver and surface
The traditional methods of
communication between the diver and the surface was by an agreed series of pulls
on the diver's life line. The diver and his attendant could signal to each other
and could communicate very effectively. The first type of voice communication
was achieved at the turn of the 19th century. This was achieved by using a
rubber speaking tube which was devised from the speaker tube method used on
ships for communication between the bridge and engine room . The device was not
a success however and was quite short lived. At around 1920 Siebe Gorman were
experimenting on a more efficient telephone system. The first system used a pair
of speakers set into a cap which the diver wore, similar to that of an aircraft
pilot. The transmitter or microphone was fitted adjacent to the front window.
This system was superseded by a speaker-receiver device which was fitted in the
top of the bonnet. It could easily be unscrewed and replaced by a quarter turn.
Alfred Graham and Robert H. Davis were then working on a more advanced system
which allowed two divers to speak to each other under water and with the surface
also.. The diver could call the tender on the surface by pressing a chin button
which worked a bell or buzzer on the telephone box at the surface. This system
was used extensively throughout the Royal Navy for many years. Another form of
telephone was also used which employed a headband with 2 speakers and a receiver
which was pressed against the diver's throat. The receiver was aptly called a
Laryngaphone.
There were several ways of
transmitting the sound to the diver but the best way was found to be to embed
the telephone cable into the diver's breast rope.
Diver's telephones were notoriously unreliable. In remote locations they had to
be powered by a series of batteries. The sound quality was often poor as it had
to compete with the compressed air entering the helmet. The inside of the helmet
was often damp which further impeded the sound quality. The diver could if
required shut off the air temporally to hear the attendant on the surface. Often
the cable was required to with stand heavy strains and twisting forces.
Sometimes, however divers would blame these potential failings as an excuse to
ignore the tender who often asked unending questions of the worker below. Making
good connection was most important and the 3 pin plug was replaced by a 4 pin
plug with an extra spade pin for an additional earth.
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| Complete
Mark 4 telephone equipment for 2 divers. Manufacturers from all around the world by this time were making their own telephone equipment.
Photo courtesy of Mikael
Zingmark. |
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|
| Manufacture: Siebe Gorman & Co Ltd |
| Date of manufacture: 1930 |
| Type: Single Diver |
| Case type: Oak with brass fittings |
| Description: A compact oak case containing 3 X 1.5 volt dry cell batteries. The case has 2 blank keeper plugs , one for storing the telephone cap and one for storing the helmet cap . There is a bell inside the box to call the attendant on the surface. Inside the box is stored a headset for the attendant. In the Siebe Gorman catalogue this piece of equipment is called 'Teled' for the purposes of ordering equipment. |
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| Manufacture: Siebe Gorman & Co Ltd |
| Date of manufacture: 1930-1940 |
| Type: 2 Diver |
| Case type: Mahogany with Gunmetal fittings |
| Description: The mahogany case is 17 inches wide and 12 inches deep and 10 inches high. The telephone unit is designed for 2 divers . The no 1 diver calls by a bell and the number 2 diver a buzzer. This allows the attendant to instantly know which diver is calling. By positioning a switch in the box the 2 divers can talk and hear one another. In order to call the attendant the diver presses on a chin button initiating the bell or buzzer. The system is powered by a series of dry cell batteries which are stored in the rear of the box. |
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| Manufacture: LM Ericsson (Dykartelephon) |
| Date of manufacture: 1935 |
| Type: 2 Diver |
| Case type: Oak with brass fittings |
| Description:
A 2 diver telephone system made by LM Ericsson who are the same company
that make mobile phones to day. The case measures 81/2 inches high ( 21cm) X 15 inches (38 cm ) and 7 inches (17cm) wide. |
Can you contribute an item of telephone equipment to this section?
Please email a photo and a description to info@divingheritage.com
