DESCRIPTIONS LISTED ALPHABETICALLY
AUSTRALIA
The Port Hedland 4A chain was established in May 1970
by the Australian Department of Shipping and Transport, a government agency
responsible for the the maintenance of navigation aids along more than
12,000 miles of coastline at the time.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Turner River |
Master |
84.820 kHz |
20° 33' S 118° 29' E |
| Mundabullangana Station (shared) |
Red |
113.0933 kHz |
20 °25' S 118° 04' E |
| De Grey River |
Green |
127.230 kHz |
20° 21' S 118° 59' E |
When the number of iron ore carriers using the ports in northwest
Australia increased, it was deemed necessary to install another Decca chain.
As a result, the Dampier 8E chain was established to provide
precision navigation for shipping in the Cape Dampier area off Western
Australia for 300 miles of coastline. The Dampier chain also provided coverage
for Port Walcott (20.5833° S, 117.1833° E).
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
Woodbrook (inland from
Roebourne) |
Master |
85.635 kHz |
20° 53' S 117° 08' E |
| Mardie Station |
Red |
114.180 kHz |
20° 59' S 116° 21' E |
| Mundabullangana Station (shared) |
Green |
128.453 kHz |
20° 25' S 118° 04' E |
Installed as Multipulse chains from the onset, both chains were collapsed
around the 1987-1989 time period.
BACKGROUND
Australia had always taken a deep interest in the Navigator system and,
as part of Decca's expansion campaign, sale personnel gave a number of
presentations including a major symposium in Sydney organized by John Lucken.
The final opportunity came in a rather roundabout way. In the
1960's, Japan's shipbuilding and motor car industries were expanding rapidly
and as Japan has no natural source of iron and steel it was necessary to
import large quantities of ore. Australia, although thousand of miles away,
was the source selected. Japan had its own Decca Navigator coverage and
many of the ore carrying vessels were already equipped with receivers.
The ore carriers were large and the channels in Northern Australia were
twisting and narrow. Decca was clearly a logical solution to the problem
therefor two chains were built - one in Dampier and the other in
Port Hedland.
Dampier proved its worth to the large bulk iron ore carriers which navigated
a narrow, twisting, 20 mile channel through off-lying shoals. Besides covering
the .'confluence of shipping routes off Cape Dampier', the chain
provided accurate navigation in the approaches to Port Walcott, a new iron
ore facility being developed in the area.
The decision to install Dampier was announced by the Hon. Peter Nixon,
Australian Minister of Shipping and Transport, speaking at the first Australian
Coastal Nav Aids Symposium held in Canberra in December 1971. To meet an
urgent operational requirement, the Dampier Chain was built from scratch
in seven months using 1880 type equipment and went into operation in July
1972. Norman J. Clarke (Nobby) from Decca's Chain Implementation Department
oversaw the construction and commissioning of the two chains and then joined
the Australian Department of Shipping and Transport. His family emigrated
to join him there and they now live near Sydney.
Amalgamated Decca Surveys Pty Ltd also proposed chains for Wallal Downs,
Derby and Gladstone but these were never built. The frequencies and coordinates
shown above came from the Chain Basic Data (DN Systems
Planning Dept. New Malden) whereas the names came from the proposal.
Any breaks or disturbances of normal Decca transmissions were broadcast
as "Decca Warnings" by the coast radio stations in the vicinity. These
were Perth Radio (VIP), Carnarvon Radio (VIC), Broome Radio (VIO) and Darwin
Radio (VID)
Additional info on the Australian
chains can be seen here.
BAHAMAS
This was known as the AUTEC chain and was built for the United States
Navy The acronym means Atlantic Undersea Test and Evaluation Center.
It's still around today and based on Andros Island, Bahamas. AUTEC's purpose
is to be the U.S. Department of Defense and Navy range of choice for conducting
undersea warfare testing and measurements in the Atlantic. Decca was used
to provide accurate position fixes to support the research which was being
conducted on the AUTEC range.
Back then, the chain was run from the New York office of Decca Navigator
Systems Inc (DNSI) but installed by the personnel from the UK. DNSI
was the company established in the USA to give Decca a presence in North
America thus providing a single point of contact for all the activities
being pursued in the '60's and '70's.
This chain ran successfully as a Mk10 system with 820 control racks
but had big problems with salt deposits on the insulators thus degrading
performance. Decca tried all sorts of things like MS4 silicon grease but
nothing really improved the situation until the rain washed off the salt.
Eventually the stations were abandoned and the equipment was shipped to
the UK for refurbishment and redeployment. . No information is available
on the approximate opening or closing dates for this chain.
Bill Gaston of Marco Island, Florida and Christopher Rose, a former
Decca employee have identified the locations of the former Decca stations.
The Master was located on Pipe Cay in the Exumas. The Better Boating Association
(BBA) Bahamas Chart Kit 4th Edition even has it noted on page 49. Another
reference lists a Decca station on Great Exuma Island which is considerably
south of Pipe Cay. Golding Cay, off the coast of Andros Island and Eluthera
are the other two sites. Golding Cay is a rock in the ocean, not much bigger
than a football field and situated at the entrance to South Bight, on the
east side of Andros Island.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Pipe Cay (Central Exumas) |
Master |
|
24 14' 46"N 76 31' 20"W |
| Great Exuma Island (2 km NW of Georgetown) |
Red |
|
23 32' 00"N 75 46' 20"W |
| Golding Cay (off Andros Island) |
Green |
|
23 13' 12"N 77 36' 10"W |
| Eluthera Island |
Purple |
|
24.9314N , 76.1900W |
Christopher Rose of Orléans, France briefly describes the
conditions. "Our accommodation was composed of portacamps - very makeshift.
We were originally supplied by a yacht, then a converted coast guard cutter
and finally once a month by a seaplane. The staff did three month shifts
on the cays then had a two week break working at head office in Nassau.
We were a mixture of British and Americans I think, all ex-servicemen,
but so was everybody in those days. Rotations were slow as people did not
like being moved around too much. I once spent more than two years in one
station in Vietnam. I heard a story from the Persian Gulf of somebody driving
his replacements off with his rifle."
Dan Ahart, a serious traveller, describes what he saw on Pipe Cay. "Our
first stop was the abandoned U.S. Navy DECCA station on Pipe Cay. The station
has been abandoned for about 20+ years, but it was once a communications
station of some sort. I don't know what DECCA stands for, but knowing the
military's penchant for acronyms, it probably has something to do with
defense communications. The layout looked very familiar to me because I
spent some time at similar stations when I served in the Air Force. It
had the standard military generator building supplied by diesel fuel via
an above ground pipe from a remote storage tank. Closer to the pier was
the all purpose building, which included living quarters for at least five
and maybe as many as nine personnel and an electronics equipment room.
Adjacent, was the foundation of the antenna tower. Interestingly, the boiler
for distillation of fresh water had not been removed".
Select this link to see photos of the Bahamas
chain.
BANGLADESH
Bangladesh Chain 6C
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Comilla ( near Chandpur) |
Master |
85.185 kHz |
23° 26' 60"N, 91° 12' 0"E |
| Dohazari (near Chittagong) |
Red |
113.580 kHz |
22° 09 46 N, 92° 03 31 E |
| Khulna (near Jessore) |
Green |
127.788 kHz |
22° 34' 60"N, 90° 13' 0"E |
| Mymensingh |
Purple |
70.988 kHz |
24° 44''34"N, 90° 23' 33"E |
BACKGROUND
The Bangladesh chain was originally a Mk V survey built in what was
then East Pakistan in the late 1950's for the hydrographical resurveying
of the massive Ganges Delta after each monsoon. This was done with a fleet
of boats using echo sounders during daylight hours. The huge changes of
the river courses and sand banks after each monsoon made river transport
difficult and severely hampered one of the main means of transportation
in the country. This resurveying was used to expedite re-use of the waterways
after each monsoon.
The war of Independence in the early 1970's seventies led to the formation
of the new country of Bangladesh, and during the war, the Decca chain went
off the air. After cessation of hostilities, it was refurbished as a Mk10
chain as part of British Government aid programme. One of the stations,
Red, near Chittagong, had been destroyed in the fighting, so the opportunity
was taken to re-build on a new site about 20 miles south at Dohazari. All
the other stations used the existing buildings.
At the time of re-building there were tremendous difficulties. The Red
station was reputed to have been built with the first cement to come into
Chittagong after the war. Malnourished children were everywhere and smallpox
was endemic. Smallpox was actually finally eradicated from Asia by the
World Health Organization while the chain was being built. Chandpur, close
to the Master station, had one of the last of the world's smallpox outbreaks.
Decca engineers did not have enough fuel to boil the drinking water, but
luckily potable water came from a deep tube well and was reputed to be
good.
While one Decca engineer was alone at the Red station, a battalion of
the Bangladesh Rifles came into the compound to take the station over as
a billet. When he walked out from the inspection bungalow to greet them,
they hastily backtracked out of the gate - probably surprised to see a
European in such a remote location.
The Dohazari Red slave was at the end of the railway line south from
Chittagong. When the Decca station was being built, there was no timetable
posted. Decca arranged for a runner to be posted on the station platform.
Whenever a train arrived, he would run into the Decca compound to announce
its arrival.
During the stability survey, Decca used the Government inspection bungalow
at Jessore as a monitoring point, because it had a trig point (coordinates)
at the corner and its position was therefore known. The monitoring station
was set up in a bedroom, but they were hastily removed when the President
came to town and slept in the room.
The monitoring station antenna was finally installed on the roof of
a civil servant's house in Dhaka, the capital, and the whole chain was
run by the Bangladesh Inland Waterways Transport Authority (BIWTA).
All stations ran on local generators and had masts of 150 feet using T-array
aerials. Transmitters and phase racks were thermionic, even after the re-furbishment.
Being so close to the equator, the skywave effect was enormous.
Starting around 16:00 hours, accuracy degraded rapidly. The chain was reopened
by Judith Hart, Minister of Overseas Aid in the British Labour government,
in 1975. This chain had the distinction of being one of the few (or the
only) chain used for inland water navigation. The chain was still in use
in 1985. (Does anyone know the exact date that it closed?)
The name of the capital "Dhaka" caused endless confusion when Decca
employees tried to explain who they worked for.
A map of the Bangladesh chain and photos can be viewed
here.
CANADA
The contract to build Canada's four Decca chains was signed in 1957
and by 1958, it is confirmed that one of the chains was in full operation
and in use by The Royal Canadian Navy. The other chains became operational
shortly thereafter and entered a lengthy acceptance period .
John Adams of the Canadian Coast Guard provides this summary of
the Decca Navigator chains, "Following several years of testing, the first
official Decca navigation service in Canada was established in 1961. The
service consisted of four Decca chains". It is believed that 1961 is the
official acceptance year for all the chains. The Canadian licencee
for Decca navigator was Computing Devices of Canada, Ottawa Ontario".
In 1952, the Canadian agent for Decca was S. Stephenson, P.O. Drawer
99, 1175 Bay St., Toronto. Telphone: Midway 7363.
Cabot Strait Chain 6B
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
Grindstone, Iles de La Madeline
Islands, Quebec |
Master |
85.180 kHz |
47.350ºN, 61.933º W |
| Channel Port-aux-Basques, NF |
Red |
113.5733 kHz |
45.633ºN, 59.233º W |
| Antigonish, N.S. |
Green |
127.7700 kHz |
45.733ºN, 61.900º W |
There was no Purple slave for this chain. This service was discontinued
in October 1982.
Nova Scotia 7C
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Chester, Nova Scotia |
Master |
85.3700 kHz |
44.533ºN, 64.233ºW |
| Alma, New Brunswick |
Red |
113.827 kHz |
45.560º N, 64.933º W |
| Jordan Bay, Nova Scotia |
Green |
128.055 kHz |
43.700º N, 65.233º W |
| Ecum Secum, Nova Scotia |
Purple |
71.142 kHz |
44.967º N, 62.150º W |
7C was the first Canadian chain. Service was discontinued in March 1982
In the Nova Scotia chain, the transmitters were manned 24 hours
per day. To ensure operational readiness, the transmitters were "rotated"
at both the master and slave sites in sequence. Starting at 12:00 noon,
the operational transmitter at the Master station was dropped and it became
the spare. The one that was the standby unit now became operational. The
one that was previously the spare became the standby unit. At 10 minute
intervals, the same sequence followed at the Red , Green and Purple slave
sites. On subsequent days, the the sequence continued to ensure that all
three transmitter "modules" were on-line at regular intervals. Of course
if a transmitter was down for some serious maintenance, the round-robin
sequence would have been shared among two transmitters only. Rotating the
transmitters at noon was done for a reason. It was deemed that the "atmospherics"
were most stable at this time of the day in the VLF band and doing it then
would minimize any potential disruptions to the users of the system.
Anticosti Chain 9C
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Port Menier, Anticosti Island, Quebec |
Master |
85.725 kHz |
64.450º W, 49.850º N |
| Shippegan Island, New Brunswick |
Red |
117.157 kHz |
64.683º W, 47.850º N |
| Natashquan, Quebec |
Green |
128.587 kHz |
61.817º W, 50.183º N |
| Sept Iles, Quebec. |
Purple |
71.437 kHz |
66.617º W, 50.150º N |
John Molloy-Vickers provides a background note for this chain. "There
was an evaluation chain (9C) covering Montreal to Quebec City and it was
installed in November 1957 by Decca Navigator and CDC. It was Mk10
chain with 820 control racks intended for airborne use on the terminal
approaches to Montreal's Dorval airport. The 1958 Montreal ICAO meeting
killed it and it the chain was moved to become the Anticosti Chain 9C".
This service was discontinued in March 1984.
East Newfoundland Chain 2C
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Port Blandford, Newfoundland |
Master |
84.4650 kHz |
48.350º N, 54.167ºW |
| Pouch Cove, Newfoundland |
Red |
112.6200 kHz |
47.7667ºN, 52.7667º W |
| St Lawrence, Newfoundland |
Green |
126.6975 kHz |
46.917º N, 55.383ºW |
| Comfort Cove, Newfoundland |
Purple |
70.3875 kHz |
49.350ºN 54.867º W, |
This service was discontinued in December 1986.
BACKGROUND
The St Lawrence Seaway was the starting point for Decca's expansion
into North America and four chains were built for the Canadian Government.
These chains provided excellent coverage and were widely used for fishing
operations. It was an early and important development for the company..
According to an article in Decca Navigator News (Sept 1976), Decca Radar
Canada Limited and The Decca Navigator Company (Canada) Limited were set
up in 1953. An extensive sales and service organization to meet the demand,
particularly for radar was established with headquarters in Toronto and
was followed by a steady expansion.
In 1957 the manufacture, rental and servicing of shipboard Decca Navigator
receivers passed to Computing Devices of Canada under a prior North American
licensing arrangement. With the transfer of some Decca personnel from Decca
Canada and the UK, Computing Devices Company (CDC) formed a marine electronics
sales and service organization in the Atlantic Provinces and at the same
time were also appointed representatives for Decca Radar equipment for
this area of Canada. Concurrent with these developments, Decca Navigator
chains of transmitting stations were erected in Eastern Canada, and as
a result of proving trials, four Decca Chains were purchased by the Federal
Ministry of Transport to provide better facilities for increased shipping
expected with the opening of the St Lawrence Seaway in 1959 and to assist
the development of the Eastern Seaboard fisheries. The Canadian fishermen
in particular rapidly equipped their vessels and CDC commenced manufacturing
receivers.
At the same time, a heavy investment was made by CDC in providing service
stations even in remote parts of Newfoundland and Nova Scotia.. Computing
Devices added to their marine product range and operated under the divisional
title of ComDev Marine. By 1976, some 500 local fishing vessels were equipped
with Mk 12 or Mk 21 receivers.
Decca Radar (Canada) Ltd, since its establishment, had achieved great
success in meeting the demand in Canada. In addition to a wide range of
shipborne radars - no less than 28 new Decca equipment types were introduced
for the '70s - the Company had been active in developing and supplying
advanced equipment for Vessel Traffic Management facilities and for engine
room control and monitoring systems.
When the Canadian chains closed for good it was noted that the Nova
Scotia chain was only one transmitting the old 'V' format yet the other
three chains had been upgraded to Multipulse. By the end, certain tubes
had became very scarce and the only source for new tubes by the early 1980's
was in Czechoslovakia.
Select this link to see a map of the
Canadian chains.
DENMARK
DANISH CHAIN 7B
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Samsø Island, Denmark |
Master |
85.365 kHz |
55.950° N, 10.583° E |
| Møn Island, Denmark |
Red |
113.820 kHz |
54.950° N, 12.467° E |
| Højer, Denmark |
Green |
128.048 kHz |
55.017° N, 08.717° E |
| Hjørring, Denmark |
Purple |
71.138 kHz |
57.450° N, 10.050° E |
BACKGROUND
Denmark was The Decca Navigator Company's first overseas chain. After
the English chain 5B was built, it was realized that more receiver rentals
would be required in order for the new company to prosper and profit. With
this in mind, the Danish chain was built and operated by Decca with a subsidiary
company in Copenhagen. Immediately the overall Decca coverage was roughly
doubled. So too were many of the operating expenses. Although the number
of rentals did not double, the significance of the overseas development
was considerable, laying the groundwork for expansion in the rest
of Europe.
Around 1990, the Danish Government purchased the Danish Chain 7B from
the Decca Navigator Company Ltd for a low price. Later, after arbitration
between Racal and the Danish Government, a Danish court increased the amount
of compensation. After the purchase, the Danish Government levied User
Charges on their fishermen who used Chain 7B.
Select this link to see the Danish
chain.
Photos of the Møn Island station (off-site link) can be viewed
here.
ENGLAND
ENGLISH CHAIN 5B
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Puckeridge, England |
Master |
85.000 kHz |
51.817° N, 00.083° E |
| Norwich (aka Shotisham), England |
Red |
113.333 kHz |
52.550° N, 01.333° E |
| Lewes, Sussex (aka East Hoathley), England |
Green |
127.500 kHz |
50.917° N, 00.150° E |
| Warwick (aka Wormleighton), England |
Purple |
70.833 kHz |
52.200° N, 01.367° W |
BACKGROUND
The first chain of Decca Navigator stations was established in southeast
England in 1946. All stations had unbroken transmissions, 24 hours per
day.
With its short base lines and high radiated power, it performed well
and despite its lack of Lane Identification, it provided excellent
service to the early users. It was the English chain which established
the reputation of Decca for both accuracy and reliability. Furthermore,
it was this chain that provided the "test bed" for the development of Decca
and was the centre for much of the promotion of the system.
It was in these early days that the foundations of the receiver rental/maintenance
system were laid. An effective organization was set up in the UK and, as
time went on, this organization spread world-wide. The effectiveness of
this network was a great contributor to the spread of the System overseas.
In the promotion of every overseas chain, there were air and/or marine
demonstrations of the system using the English chain. As a sales "tool",
the chain was invaluable.
Overall maximum dimensions of a typical transmitter site were 1100 feet
by 700 feet but the actual ground area occupied by the station was slightly
less than that (750 ft. by 150 feet.) The buildings for the transmitters
were simple, single storey, prefabricated units set on a concrete foundation.
The mast and aerial system on the Decca Navigator Ground Station was
of special design and had an unusually high degree of efficiency at the
low frequencies employed. Field strength measurements showed that the radiation
efficiency was some 45%. Transmitter output, being at 2 kilowatts, meant
that 900 watts could be expected as radiated power. This power level was
deemed sufficient to overcome unfavourable reception conditions.
COVERAGE: This map of the UK illustrates the coverage
of the English Chain. With respect to the master station located just north
of London, the solid circle indicates 300 miles distance while the dashed
circle is 350 miles. That was roughly the range deemed for reliable reception
of Decca signals during daytime. The British Admiralty designated a range
of 240 miles from London as being the furthest reliable distance. From
this map, dated 28/8/46, it is very evident why Decca was only useful as
a coastal navigation aid.
After it was found the English chain could not cover the whole of the
UK 24 hours per day because of skywaves ruining lane identification,
the transmitter power was stepped down and for the last 25 years of operation,
the effective radiated power was only in the area of 40 to 100 watts.
Donald W. Rayner Sr. worked at the Red slave of the English chain in
Norwich between 1946 and 1948. He recalls this period with great clarity.
"Notice on Petty Officer's bulletin board at RN signal school, Leydene,
Hants in Jan, 1946 - Seeking to hire W/T ratings being released
from post war service. Applicants to contact Decca Navigator in London.
I, and one Norman Thomas, a ‘Geordie’ Both applied and later were assigned
to a site located on the ‘Kidner’ farm, Poringland/Shotesham All Saints
near Norwich, Norfolk. We were met by a John Mears who became station manager
and a contact man from DECCA in London. With this minimum staff, and a
local contractor, construction started. Throughout the ensuing months the
station took shape. It would be close to the end of 1946 before we got
to transmitting.
During this time we had a visit from one, H. Toller Bond who was identified
as being the head of design and engineering. On one visit he brought a
gentleman identified as a ‘Mr. O’Brien’ the American inventor of the system.
He was a US amateur radio enthusiast who had presented his ideas to the
US military during the war and was turned down. Being a friend of a Mr.
Schwartz who was president of British DECCA Records in London, he went
over and sought his help.
The Royal Naval Signal school where Toller Bond was on staff
became involved in design of the system. I believe the RAF may also have
been involved since I met several company officers who had been ex-RAF.
Preliminary testing of a temporary ‘chain’ occurred during the Normandy
landings, pinpointing areas for close support for troops on the ground
but I have no direct knowledge of this activity. When operations started,
we hired additional staff. Seven in, all with Mears, being Station Manager.
I got tagged as Assistant Station Manager We were assigned a small new
‘Fordson' van for transport. Our shift hours were "different" . A night
shift was defined from 6PM to 8AM with 2 days off afterwards. Since
the manager had a penchant to be absent for days, hence my unpaid promotion
to Assistant Manager.
Equipment breakdowns were frequent as were trips to London repair shop.
The special receivers were housed in a separate small building that was
completely encased in fine wire mesh and grounded with the antenna mounted
on its roof. Output cables were under concrete to the main transmitter
building. Two large diesel generators were housed in a separate building
with one running at all times due to power outages occurring frequently.
We had an underground diesel fuel tank and a gasoline tank used for the
starter motors mounted on the diesel generators.
Domestic notes: We were all housed in private homes locally but these
were mostly farm cottages for farm workers. We asked for housing. Decca
sent the company Sec. Treasurer to discuss our needs. Nothing happened.
This action eventually prompted me and my wife to leave and emigrate to
the United States for better job opportunities.
In 1993 I visited this old site. The main 138 foot tower was gone replaced
by a smaller antenna system.Other changes included the elimination of the
diesel generators.. The staff consisted of one operator and a small
house for him and wife. With the station due to close, both were planning
to return to India, their homeland. On a personal note, I was never
an engineer....just a happy go lucky ham interested in electronics. Those
large high power, low frequency transmitters with their glowing rectifiers
fascinated me.
I was 25 then. Now I am 82 (2003) and living in this seniors village
nestled in the foothills of the Allegheny mountains in Pennsylvania.
I’ve seen it all and done it all in ham radio. It's been a blast".
NORTH BRITISH 3B
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Kidsdale, Scotland |
Master |
84.645 kHz |
54.700° N, 04.417° W |
| Clanrolla, N. Ireland |
Red |
112.860 kHz |
54.500° N, 06.333° W |
| Neston, South Wirral, England |
Green |
126.968 kHz |
53.267° N, 03.050° W |
| Stirling, Scotland |
Purple |
70.538 kHz |
56.067° N, 04.067° W |
Coverage of the Irish Sea. Stirling was also the Red slave for
the Northumbrian chain.
Photos of the North British Chain can be viewed
here.
NORTHUMBRIAN 2A
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
Allerdean Greens, England
(a.k.a. Berwick) |
Master |
84.455 kHz |
55.700° N, 02.033° W |
| Stirling, Scotland |
Red |
112.607 kHz |
56.067° N, 04.067° W |
| Peterhead, Scotland |
Green |
126.683 kHz |
57.517° N, 01.850° W |
| Burton Fleming, Yorkshire, England |
Purple |
70.379 kHz |
54.133° N, 00.317° W |
BACKGROUND
This chain was established to cover a gap in the North Sea and the Firth
of Forth. Along with the Hebridean chain, it used re-furbished 820
series, thermionic valve equipment bought back from the USA. The USA had
two experimental chains - one in California used for airborne trials, and
one around the Bahamas reputed to have been used for submarine navigation.
It is not certain which chain ended up where.
The Northumbrian chain had two shared stations - Stirling and
Peterhead. This meant that the masters at Kidsdale and Orkney had to be
synchronized. In the end five chains were synchronized to allow slave sharing.
Decca trivia - What was the population of Allerdean Greens at
the time? Answer - Pop = 6. It was a minor hamlet south of Berwick
Photos of the Northumbrian chain can be found
here.
SOUTH WEST BRITISH 1B
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Bolberry Down, Devon, England |
Master |
84.280 kHz |
50.233° N, 3.833° W |
| St..Helier, Jersey, Channel Islands |
Red |
112.373 kHz |
49.250° N, 2.083° W |
| St.Mary's, Isles of Scilly, England |
Green |
126.420 kHz |
49.933° N, 6.300° W |
| Llancarfan, Wales |
Purple |
70.233 kHz |
51.433° N, 3.383° W |
Chain 1B was officially opened on July 1952 on the Motor/Vessel Vecta.
The chain provided coverage for the south and south east coasts of Ireland,
Cornwall and the Scilly Isles.
For more information on Decca France, select
this link.
GERMANY (3F)
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Brilon, Germany |
Master |
84.7400 kHz |
51°27'N, 8°43'E |
| Coburg, Germany |
Red |
112.9867 kHz |
50°20'N, 10° 59'E |
| Zeven, Germany |
Green |
127.1100 kHz |
53° 17'N 9°16'E |
| Stadtkyll, Germany |
Purple |
70.6167 kHz |
50° 22'N 6° 32'E |
BACKGROUND
The original German chain was set up to assist with the Berlin air-lift
and the support of forces in the region and was assigned a chain ID of
9B. An ex-Decca sales manager who was in an RAF navigator during this period
said that the worst cargo was coal. The sacks had to be manhandled in and
out of the aircraft thus leaving everything and everybody covered in black,
dusty powder. After the initial crisis was over, the chain was probably
left in place to support the RAF aircraft in West Germany who already had
an installed base of Decca receivers.
By December 1951, a new German chain had been built and was officially
opened on January 17, 1952 at the offices of the Telefunken Company in
Dusseldorf. Assigned as chain 3F, it opened for business using 2.5 kw transmitters
and antenna masts that were 100 meters high. Later on , the chain was upgraded
to Multipulse. The chain frequencies shown in the table are those for 3F.
One of the stations was located in the pretty village of Stadtkyll,
south west of Cologne, in the Eiffel region of Germany. David Jones remembers
the station when he was there in January 1977. "The German caretaker at
the station was a tank driver in WW2 and would speak with pride about the
smooth ride inside his Panzer tank as it went through a house". It is believed
that the Zeven station was also the Green slave for the German chain 3F.
An interesting note was spotted in a Decca technical publication dated
1973." WARNING - Although the
Frisian Islands chain is using the same frequency as the old German
chain, namely 9B, the ground stations are not in the same positions and
therefore the old German charts cannot be used with the Frisian Islands
chain. See notice to Mariners 1977(p) of 1967 ". John Molloy-Vickers
provides an brief history of the German chain which explains the reason
for the warning..
"The 9B chain (old German chain) was set up for air use but it gave
poor coverage on its north coastal areas. Decca converted it to Mk 10 system
somewhere around 1964 in an effort to improve air useage for Mk 19 receivers
and their follow-ons. The chain used to be run by German Air Traffic Control
(Bundes Flugsicherung) but they were rapidly losing interest as there were
few German national users. British Airways liked it and so did the UK Ministry
of Defence. When the Frisian Islands chain was installed it took the 9B
chain frequency in order to have good coastal coverage and the German chain
switched to the half chain frequency of 3F which is only suitable for the
later types of receivers. Obviously, any receiver switching to 9B after
the changeover and using the original German charts would see garbage!
After this change, chain 3F was no longer of any marine interest.
The "new" German chain was also to be run by Decca under contract to
the German Ministry of Defence Various additions were installed to cover
their particular requirements. The original chain construction used massive
Telefunken transmitters (as in radio station type systems) rather than
the current multiple modular Decca designs with separate power supply systems.
The slaves were unattended at night, instead, relying on a remote alarm
system to call in an operator from his home to service any alarm . This
was not permitted on a Decca managed station in that era! Back then
, the station was sealed and was automatically flooded with CO2 in the
event of a fire alarm".
A map of the German chain is available
here.
INDIA
Bombay and Calcutta were contracted in 1959 according to Decca records.
Bombay opened in 1962 while Calcutta became operational in 1964.
Bombay Chain 7B
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Savarkundla |
Master |
85.3650 kHz |
21.3377N, 71.3052E |
| Bilimora |
Red |
113.820 kHz |
20º45'40"N, 73º02'17"E |
| Veraval |
Green |
128.048 kHz |
20º57'07"N, 70º20'13"E |
| Dhrangadhra |
Purple |
71.138 kHz |
23º00'14"N, 71º31'39"E |
Calcutta Chain 8B
Stations were located in the States of Orissa and West Bengal.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Balasore |
Master |
85.5450 kHz |
21º29'08"N, 86º55'18"E |
| Patapur |
Red |
114.0600 kHz |
20º50'28"N, 86º 27'28"E |
| Bishnupur |
Green |
128.3175 kHz |
23º04'06"N, 87º 19'00"E |
| Diamond Harbor |
Purple |
71.2875 kHz |
22º10'18"N, 88º12'25"E |
Salaya Chain 2F
This chain was installed in 1978 specifically as a navigation aid for
the Gulf of Kuchchh marine traffic using 1880 series equipment. It
was officially opened on February 15, 1979. Very Large Crude Oil Carriers
(VLCCs) brought crude oil from the Persian Gulf to the refineries in the
state of Gujarat and in particular through the deep water channel to the
off-shore oil terminal at Salaya. Stations sites in the Salaya chain were
all near rural villages that were some considerable distance from a major
city.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Mandvi |
Master |
84.5550 kHz |
22° 52' 26.80"N, 69° 24' 00.02"E |
| Kuranga |
Red |
112.7400 kHz |
22° 03' 29.92"N, 69° 10' 29.74"E |
| Dhuvav (Dhuwao) |
Green |
126.8325 kHz |
22° 28' 48.54"N, 70° 07' 43.09"E |
| Naliya |
Purple |
70.4625 kHz |
23° 15' 04.32"N, 68° 49' 00.03"E |
BACKGROUND
It was from India that the first non-European Decca chains were ordered.
The Decca Navigator Co. of U.K. was contracted in 1955-56 to establish
a hyperbolic position fixing system in India. The Bombay and Calcutta chains
of four stations each were established between This chain used the 820
series tube equipment when first installed between 1958-62. The production
of Decca Lattice navigation charts was taken up in 1967 by the Indian navy
with the first of the series covering the approaches to Paradeep Port.
These were first published in April 1968.
The Director General under the Department of Lighthouses and Light-Ships
was the sole authority for administration and management of light-houses
and their principal navigation aids such as Decca Navigator. There were
three chains in India. The Department of Lighthouses and Lightships
is a subordinate office under the Ministry of Shipping and headed by the
Director General of Lighthouses and Lightships. The Headquarters
of the Department of Lighthouses and Lightships is situated at Noida. Decca's
main supporter was Mr. Lahiri of the Indian Lights Authority as it was
known at the time.
David Jones describes one incident while in working for Decca in India.
"Base lines were relatively short but journey times between stations were
measured in many hours depending on circumstances. Our team from Diamond
Harbour once made the 50 mile drive back to Calcutta in an elderly Ford
car which had a broken fuel pump. Every couple of miles, the driver would
stop the car, remove the carburetor float chamber cover and
pour in another cupful of gasoline".
In 1992, Bombay and Calcutta were replaced by Loran-C chains of
three stations each. The Salaya chain closed as of December 2000.
All three Indian chains can be viewed here.
INDONESIA
In 1974, The Decca Navigator Company signed a contract with Perusahaan
Pertambangan Minyak Dan Gas Bumi Negara (PERTAMINA). This organization
acted on behalf of the Indonesian Government for the supply of a Decca
chain to be installed on the Sumatra coastline in the central area of the
Malacca Straits. It was to be called the Dumai Chain.
The layout of the chain was configured to provide accurate navigation
in the approaches to the new oil terminals which were being developed
at Dumai and Sungaipakning. In addition, it going to provide accurate coverage
over the whole central area of the Malacca Straits. The installation of
a Decca chain in this important and hazardous seaway marked a significant
step forward in the march of marine safety in its day. For the Decca company,
there was a lot of concern as to how they were going to erect masts in
the swamps with no solid footings. By the late 1970's, all hopes of building
the chain were totally dead. Dave Baker of Decca bought all the equipment
back from the Indonesians (PERTAMINA) and sold the master and two slaves
to the Iranian PSO (Ports and Shipping Organization) for the proposed Strait
of Hormuz Chain. Due to the Iranian revolution, the Strait of Hormuz chain
was never built . The Purple Slave 1880 cabinet intended for Hormuz instead
saw active service as the Purple slave of the Holland Chain in Thorpeness,
Suffolk, UK.
Select this link for a map of the
proposed Dumai chain.
IRAN
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Bandar-e Deylam |
Master |
85.0050 kHz |
30°1'7"N, 50° 9'29"E |
| Abadan |
Red |
113.3400 kHz |
30.4° N, 48.2° E |
| Bushire |
Green |
127.5075 kHz |
28° 58' 38"N, 50° 51' 9E |
In the North Persian Gulf Chain 5C, all the stations
were located in Iran and based around the port of Abadan. Both chains in
the Persian Gulf were operated by The Middle East Navigation Aids Service
(MENAS). It was established in 1950 to serve the maritime industry in the
Arabian Gulf, but it can trace its origins back to 1911 when tanker shipping
entered the Gulf to collect cargoes of oil. MENAS, an independent, not
for profit organization, while registered in the United Kingdom, has its
centre of operations in Bahrain at a base established in 1950 following
the donation of land in perpetuity by the then ruler, the late Amir, HH
Shaikh Salman bin Hamad Al Khalifa. an entirely independent authority having
no national sponsor or commercial owner. Revenue is drawn solely from navigation
dues paid on vessels above 2,000 Net Registered Tonnage (NRT) using Gulf
waters and, this revenue is invested for the safe navigation of shipping
passing through the Gulf. Chain 5C provided coverage for vessels using
the waters along the coastline of Iran.
John Molloy-Vickers, one of the installers for the North Persian
chain, gives his perspective on the installation. " I spent Christmas 1960
and a few months thereafter in Persia helping to install the North Persian
Gulf chain. Nobby Clarke, Ernie Easter and Reg Odams were the principals
from our department. The problems were huge. All the equipment for the
three stations had been dumped in a yard after delivery to the National
Iranian Oil Company in Abadan. Although they had been carefully marked
and labelled in the UK, by the time they were ready to be deployed
it was nearly impossible to tell whether a crate contained an air conditioner,
a toilet bowl or a transmitter.
Equipment was loaded in some cases onto landing craft to send it on
its way. It was a major exercise since we had to start from scratch and
build complete stations with all facilities for operating staff and servants.
We became plumbers, electricians, sewerage experts and medical attendants
to the locals in a very short time. We initially lived in tents with scorpions
and snakes for company. When we had the living quarters built, goats were
slaughtered on the back door step by our Indian cooks etc. Through our
interpretter at Deylam I recalled that one of the locals asked for
sidecutters. When asked what for, he said to "cut off his wife's finger"
to recover her ring before he buried her in the cemetery next door to our
station.
One day, I rather stupidly jumped into the Shatt al Arab waterway at
Korramshur to cool off and surfaced next to a dead cow. I was keeping a
wary eye on the Iraqi guards who always watched us from the other side
and I was not looking out for flotsam.
I believe the chain closed on May 1, 1980".
Phil Jones, a former Decca employee who maintained the Persian Gulf
Chains in the late 1970's provides this account of the situation in Iran
around the time the Shah of Iran fell.
"Things got scary just before the fall of the Shah and the rise of Ayatollah
Khomeni. Many of the knowledgeable expatriates simply moved away but the
Decca crews were considered essential. Logistical problems arose in Iran
where it was never easy to get parts under normal circumstances. Procurement
of vacuum tubes was especially difficult. I remember smuggling some in
my suitcase on a return trip from UK on one occassion.
Going into towns or villages as a visible Westerner was risky to say
the least. During the American hostage crisis, a lot of hatred developed
against the west. Once, we had to flee and hide for our lives on
a routine shopping trip just to get groceries. Back in those days it was
impossible to make a phone call locally, let alone internationally
and it took about 3 to 4 weeks to get a letter from home. All our communication
between stations was made possible through short wave radio. We all became
radio ham experts. By that, I mean we could easily understand each other
no matter how garbled the voice was at the other end. Sometimes we did
take advantage of this with our regional manager.
When we were were stationed on Lavan Island which was the best location
in Iran for day to day living, we would get instructions from our area
manager in Khorramshar ( near Abadan). If we did not like what he was asking,
we could easily say he was fading out and could he repeat that!! After
several times of repeating, he would give up but I don't think he believed
us. Life in Iran was tough to say the least back then and it gradually
got worse as the new Islamic-style regime started to grip the country.
Towards the end, getting out of Iran was probably the most dangerous thing
for me but that's another story.
The bugs were big and plentiful. (ie camel spiders, scorpions
and even snakes). .On the station at Lavan Island, one snake even came
to visit me sidewinding under the toilet door. As an ex-boy scout, one
has to be prepared but under these circumstances I never knew how to defend
myself against an irate sandviper with pants down and a toilet roll! I
suspect it was actually planted by a disgruntled local employee -
the diesel coolie, who I made do an honest days work each day when I was
there. I must say that some of the weirdest and most potentially dangerous
experiences happened to me while I maintained the Persian Gulf Chains".
Phil also relates this story about the Master station failure Bandar
Deylam. " It happened just before I joined Decca in the Gulf. One engineer
was on a sleeping watch when the alarm sounded in the middle of
the night. He ran into the station and saw that all 807 transmitter amps
were blowing fuses fast and furious. As soon as he replaced the fuses they
blew again. Then out the corner of his eye he noticed no aviation lights
on the mast. The reason - the whole 300 foot mast had come crashing down
in the middle of the night. Apparently the construction company used sea
water to mix the concrete for the mast anchor blocks (to save money) when
the mast was put up several years earlier. So it was just a matter of time
before the concrete failed.
After this "incident" the station was completely overhauled. Since it
had such a good maintenance history prior to the crash, it was one
place where you could actually get a good nights sleep. I guess the duty
station engineer who witnessed the mast come down also got a few good nights
sleep after that commotion.
Often, going off the air was the result of a diesel failure. Those 28
year old Listers were good but sometimes unpredictable. When I was on a
sleeping watch, the thing that often woke me up was the total silence of
not hearing the air conditioners running. You would get up in a daze, sometimes
you were lucky and the station was still on the air; sometimes not. Going
from a deep sleep to being fully awake and in 3 minutes hand cranking an
old 6 cylinder Lister (on decompression) could only be done if you were
under 30. I think now that would be case of major heart failure!
Looking back I often wonder how those stations were as reliable
as they were. Logistics was always difficult. Even diesel fuel delivery
at Bandar Deylam was by donkey! "
Phil Jones, by the way, has been involved in home audio since
he was thirteen years old. While stationed in the Persian Gulf with The
Decca Navigator Company, he designed and built speakers to pass the time
away. In the UK, many folks know him as the dude who designed and
founded Acoustic Energy (of AE-1 and AE-2 fame), then with Boston Acoustics
(Lynnfield speakers), followed by the founding of Platinum Audio. In 1998
AAD (American Acoustic Development Ltd.) was born with a manufacturing
plant is located in China. This is where Phil spends his time now. In August
2003, Phil will be moving to the St. Louis MO, to look after his interests
in PJB (Phil Jones Bass Inc), an organization dedicated to making
very high performance bass guitar amplifiers. One model is all tubes using
four 813 transmitter tubes.
A map of the Northern Persian Gulf chain can be seen
here.
Also see the U.A.E. section for more information about the Persian
Gulf chains.
.
IRELAND
The Irish Chain 7D was operated by Bord Iascaigh Mhara (Irish Sea Fisheries
Board) for mariners sailing on the west and south coasts of Ireland. All
stations were located within Ireland. Chain 7D was formally opened on May
31, 1973.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Galway (Oranmore) |
Master |
85.450 kHz |
53.250º N, 08.930º W |
| Ballydavid |
Red |
113.933 kHz |
52.200º N, 10.367º W |
| Dungloe |
Green |
128.175 kHz |
54.883º N, 08.383º W |
| Youghal (Ardmore) |
Purple |
71.208 kHz |
51.950N, 07.750º W |
Select this link to see a map of the
Irish chains and the towers. The mast at Galway (Oranmore) is apparently
gone.
ITALY
ROME: Chain ID: ??
In the late 1950's, the RAF lobbied NATO to establish a Decca Navigator
chain in Italy because the RAF had already installed
Decca in some of its low-level Canberra B8 aircraft. A two pattern
Decca evaluation chain was therefore constructed for the Rome Control Area,
however the exact date of its opening is not known at this time. Master
and Red stations were situated on the Italian mainland with the Green slave
on the island of Sardinia.
Walter Blanchard flew on some of the flight trials
and demonstrations. "Apart from demonstrations for Italian civil aviation
authorities, we also flew a considerable number of military trials based
at the Italian Air Force base in Pratica di Mare, near Rome. The main monitor
station for the chain was located there. We used an IAF Fiat G91 fighter
with an experimental set-up of three antennas spaced equally round the
fuselage to get around the loss of signal when the aircraft performed manoeuvres.
The tiny cockpit was even fitted with a Flight Log!. It was a fairly
successful trial and later on we transferred the equipment to a USAF
F-101 and carried on with trials in the UK. These trials were supported
by NATO who were looking for a low-level navigation system in Italy, but
nothing ever resulted from them and I'm not sure why. These trials were
triggered by the RAF who at the time had installed Decca in some of its
low-level Canberra B8 aircraft. I also flew the trials in those aircraft.
I believe the costs of the Italian chain were borne mainly by NATO but
Decca took advantage of it to perform civil demonstrations as well".
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Pratica di Mare (south of Rome) |
Master |
? |
41° 40' 0 N, 12° 28' 60 E |
| SE of Turni, Italy |
Red |
? |
? |
| Venefiorite (north east) Sardinia |
Green |
? |
? |
The continuous growth of commercial air traffic and the introduction
of more turboprops and turbojets increased the problem for air traffic
control in the Rome Control Area in the late 1950's. Aggravating the situation
were relatively inaccurate radionavigation systems which formed the basis
of air traffic control in this area. The mixture of aircraft types
required complex routing and radar was insufficient to get the whole job
done. To demonstrate the capabilities of the Decca Navigator system in
the cockpit, two demonstration fights by Decca's corporate Valetta aircraft
were arranged for October 14/1959. There were many other flight demonstrations
as well.
For unknown reasons, the chain did not persevere so its closing date
is not known at this time.
SICILY, CHAIN ID=?
A demonstration chain was set up in Sicily as reported in the November
1969 issue of Decca Navigator News.
For more information on Decca Italy, select
this link.
JAPAN
BACKGROUND
Japan was a land of opportunity for Decca because it relies on the sea
for its food supply and fishing is a major industry. Because Japan lacks
mineral resources, oil and steel have to be imported therefore the sea
is very vital to the country's economy.
Japan was an early user of the Decca system having bought its own survey
chain in 1960. Also, it was an early European chain user - ships picking
up receivers from Mediterranean ports when entering the area and leaving
them behind when returning to the Far East.
When Decca made made the initial contact into this marketplace, the
company found a few knowledgeable individuals anxious to learn more about
the system. There were not many but they were influential. The big names
were Shimasue and Kiyono. Mr Kiyono is still very active in Japan
and his company, SENA started renting Decca-licenced, Japanese-made
receivers starting around 1966.
In the mid-1950's, the basic problem for Japan was a shortage of money
but as the country's financial situation improved so did Decca's chances
of establishing chains. . In 1964, with Japan just beginning its up-turn
of Navigator, Decca signed agreements with the Government of Japan and
with a number of commercial organizations. These included Kobe Kogyo (now
Fujitsu) as the manufacturing licensees. All of the relationships were
most cordial and long lasting. Over the years the Japanese Government built
six chains so that the whole of Japan was covered.
Japan holds the distinction of being the last bastion of Decca having
closed down the Hokkaido chain in March 2001. This was one year later than
the UK closure. Hokkaido was also the first Decca chain to open in Japan.
The SENA Company kind enough to provide details for all six Japanese
chains. To see full details on the Japanese Decca chains, select
this link.
NETHERLANDS
FRISIAN ISLANDS 9B
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Finsterwolde, Netherlands |
Master |
85.720 kHz |
53.200ºN, 07.100º E |
| Hoejer, Denmark |
Red |
114.293 kHz |
55.017ºN, 08.717º E |
| Heiloo, Netherlands |
Green |
128.580 kHz |
52.600ºN, 04.733º E |
| Zeven, Germany |
Purple |
71.433 kHz |
53.283ºN, 09.267ºE |
BACKGROUND
Bob Peters, who was previously a Decca maintainer, provides some
information on the Dutch chains. "I worked 16 years on the Green Slave
of chain 9B until the conversion in 1985 which permitted automatic operation
and remote control. The stations of the Dutch Chains were not maintained
by Decca. Instead a Dutch concern provided maintenance.
The, was built in 1968 for merchant, fishing and yachting purposes and
the owner of the F.I.C. was the Directorate General for Public Works and
Water Management (RWS) owned and managed the chains. The Frisian Islands
Chain covered the North Sea, north of the Netherlands and Germany
and west of Denmark.
Bob goes on to describe the power system for the Green slave. Under
normal conditions, power to the site was provided by the public power system.
(380 volts 3 phase from a 10.000 volt step-down transformer). A 380 volt
feed supplied the input for two motor generators whose output was 600 volt
DC for the transmitters, 380 volt AC for the phase controls and Rasme,
a 220 volt DC output and a 50 volt DC output both for recharging the batteries.
During a power outage, the 200 V dynamo became a motor whose power source
was the 220 volt battery bank. After some time, a 6 cylinder Lister
diesel generator took over. In all, there were two motor generators, two
220 volt battery banks, two battery banks of 24 volts each
Before conversion, the F.I.C. was controlled from the Master station
which was manned 24 hours a day while the Green slave was only staffed
during normal business hours. Two men worked at the Green slave with a
one day on, one day off work schedule. For off-hours coverage,
each man was equipped with a special alarm receiver at home. The station
raised the alarm by a sudden drop of the power from the 9F transmitter
just after the Multipulse period.
Around 1985, all the stations F.I.S. the stations were converted to
run automatically and under remote control.
Although a control desk was built into the Master station, all
the information was sent to Hoek of Holland over a leased telephone line
to a second control desk. The control of chain 2E was therefore located
in Hoek of Holland, the entrance to the port of Rotterdam.
Slave station Purple in Zeven, Germany was located between Bremen and
Hamburg at coordinates 53° 17' 07"N, 09° 15' 49"E.
Providing coverage for the North Sea, it was decommissioned in December
31, 1999. The main antenna had a mast height of 93 meters while the backup
was slightly shorter at 46 meters. On hand evidence suggest it was also
the Green slave for the German chain 3F.
An interesting note was spotted in a Decca technical publication dated
1973." WARNING - Although the
Frisian Islands chain is using the same frequency as the old German
chain, namely 9B, the ground stations are not in the same positions and
therefore the old German charts cannot be used with the Frisian Islands
chain. See notice to Mariners 1977(p) of 1967 ". Something obviously
happened with the chain assignment,. Can anyone explain this mystery?
HOLLAND CHAIN 2E
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Gilze-Rijen, Netherlands |
Master |
84.550 kHz |
51.617ºN, 04.917ºE |
| Heiloo, Netherlands |
Red |
112.733 kHz |
52.583ºN, 04.733ºE |
| Westdorpe, Netherlands |
Green |
126.825 kHz |
51.233ºN, 03.833ºE |
| Thorpeness, England |
Purple |
70.458 kHz |
52° 10' N, 01° 37'E |
The Purple slave Thorpeness was added after chain 2E was established
since it does not appear in the initial chain listings. One correspondent
said he looked after this slave from 1991 through 1994. This chain serviced
the area of the Netherlands known as Europort.
With the help of Decca, large crude oil tankers could enter the Hoek
of Holland through a virtual "canal" in the sea. Initially built without
a Purple slave, it was eventually added and was located in Zeven,
Germany. Until the Purple station was functional, the master station also
transmitted the Purple signal. Since there was a bend in this canal and
the hyperbolic lines of the Red and Master and Red and Green stations criss-crossed
over the canal, a special accessory on the receiver made it possible to
use the Red and Green slave only for navigation. Because the Dutch
were very keen users of the system, they developed their own high accuracy
differential receiver for pilot vessel use. This was known as the "Brown"
receiver because Red and Green produce brown when mixed.
On Saturday the 16 April, 2011 at 10.00 o’clock the Decca
transmitting aerial of Green 9B was intentionally demolished. Red
2E came down at 13.00 hours, twelve years after Decca was switched off.
The transmitter buildings are still there. Green and Master of 9B are used
as clubhouses by a motorclub.
To view a map of both Dutch chains and the Finsterwolde mast, select
this link
NIGERIA
LAGOS 8F
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Ikorodu |
Master |
85.6400 kHz |
6 º 39'N, 3º 35'E |
| Abigi |
Red |
114.1867 kHz |
6º 30'N, 4º 23'E |
| Badagary |
Green |
128.4600 kHz |
6º 25'N, 2º 56'E |
| Abeokuta |
Purple |
71.3667 kHz |
7º 17'N, 3º 29'E |
RIVERS 7F
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| ? |
Master |
85.4600 kHz |
? |
| ? |
Red |
113.9467 kHz |
? |
| ? |
Green |
128.1900 kHz |
? |
| ? |
Purple |
71.2167 kHz |
? |
Station names unknown at this time.
MID EASTERN 3A and SOUTH EASTERN 2B
These chains were proposed but not built.
BACKGROUND
The economy of Nigeria has been closely linked to the oil industry and
the discovery of considerable reserves brought about many changes there.
For many years, there had been exploration programmes using small
Decca survey chains but as the development of the industry took place it
became necessary to install full.size, non-restricted user chains. Four
such chains were initially commissioned.
In the 1970's, important oil developments off the coast of Nigeria were
raising the urgency for effective and safe control of marine traffic. Uncontrolled
shipping would present a growing hazard to oil rigs, loading terminals
and to the large number of tankers coming in to the area. A series of areas
prohibited to normal traffic would be introduced to protect the loading
terminals and rigs and a system of traffic routing instituted to ensure
that the regulations were not violated. Tanker routes to and from the loading
areas would be laid down with a zone for coastal traffic inside the restricted
areas.
The Decca Navigator company intended to undertake all the necessary
work including the selection, surveying and clearing of sites, the erection
of antennae and the installation of technical equipment. At the end of
the project, complete operating chains would be handed over to the Federal
Ministry of Transport to be manned by Nigerian engineers trained by Decca
in the United Kingdom. The four chains were intended to give contiguous
coverage along the Nigerian Coastline using 1880 type equipment.
The Lagos chain consisted of the Master station at Ikorodu to the North
of Lagos, the Red slave at Abigi along the eastern shoreline of the Lagos
Lagoon, the Green slave at Badagary near the Benin Boarder, and the Purple
slave at Abeokuta, about 60 km north of the master station. These slaves
were intended for unmanned operation with planned visits of only
once a month and diesel generator maintenance at three month intervals.
Diesel generators were the only source of power for the Nigerian chains.
A monitoring station was located at Agbowa, about 7 km north of the master
station.
According to David Jones, a former Decca employee, only two out of the
four chains were ever built and those were a struggle. Rampant corruption
and dishonesty plagued the project. Lagos and Rivers operated for a short
time but never went into public service. It is believed that the
Nigerian Chain was the last Decca chain ever built.
The dramatic changes in world oil prices were paralleled by Nigeria's
internal political problems. There were many difficult years for Nigeria
and these lead to difficult times for the chains. As a result, the Lagos
and Rivers chains shut down before going into commercial service.
Select this link to see the Nigerian
chains and a photo of the signing of the contract.
NORWAY
The contract to establish six Norwegian Decca chains was signed
in September 1965 and the chains were formally opened on May 14, 1968.
FINNMARK (FINNMARKKJEDEN) 7E
Finnmark was Norway's first chain and it was opened on May 27, 1967
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Bøerselv, Norway |
Master |
85.4550 kHz |
70º23'28"N, 25º30'14"E |
| Kirkenes, Norway |
Red |
113.9400 kHz |
69º41'19"N, 30º03'14"E |
| Vannøy Øst, Norway |
Green |
128.1825 kHz |
70º06'20"N, 20º07'07"E |
| Nordkapp, Norway |
Purple |
71.2125 kHz |
71º09'36"N, 25º45'21"E |
| |
Orange |
116.7885 kHz |
|
HELGELAND (HELGELANDKJEDEN) 9E
Helgeland was initially 10B then became 9E. The frequencies shown below
are for the 9E chain.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Dønna, Norway |
Master |
85.8100 kHz |
66.200ºN, 12.467ºE |
| Røst, Norway |
Red |
114.4135 kHz |
67.533ºN, 12.133ºE |
| Rørvik, Norway |
Green |
128.7150 kHz |
64.917ºN, 11.167ºE |
| Mo Rana, Norway |
Purple |
71.5083 kHz |
66.283ºN, 14.167ºE |
| |
Orange |
117.2737 kHz |
|
LOFOTEN (LOFOTKJEDEN) 3E
Lofoten was initially 3F then became 3E. The frequencies shown below
are for the 3E chain.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Andøya, Norway |
Master |
84.7350 kHz |
69º08'45"N, 16º01'53"E |
| Vannøy Vest |
Red |
112.9800 kHz |
70º14'51"N, 19º30'05"E |
| Røst, Norway |
Green |
127.1025 kHz |
67º31'44"N, 12º09'30"E |
| Narvik, Norway |
Purple |
70.6125 kHz |
68º27'57"N, 17º06'02"E |
| |
Orange |
115.8045 kHz |
|
TRONDELAG (TRØNDELAGKJEDEN) 4E
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Skarsoy, Norway |
Master |
84.9150 kHz |
63.333ºN, 08.450ºE |
| Rørvik, Norway |
Red |
113.2200 kHz |
64.917ºN, 11.167ºE |
| Stad, Norway |
Green |
127.3725 kHz |
62.200ºN, 05.133ºE |
| Berkåk, Norway |
Purple |
70.7625 kHz |
62.833ºN, 10.050ºE |
| |
Orange |
116.0505 kHz |
|
Stad was shared with the Vestlandet chain.
VESTLANDS (VESTLANDKJEDEN) 0E
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Aagotnes, Sotra Island, Nor. |
Master |
84.1950 kHz |
60º24'24"N, 05º00'34"E |
| Stad, Norway |
Red |
112.2600 kHz |
62º11'35"N, 05º07'31"E |
| Shetland Island, Scotland |
Green |
126.2925 kHz |
60º02'54'N 01º14'33"W |
| Stavenger, Norway |
Purple |
70.1625 kHz |
58º47'15"N, 05º32'42"E |
| |
Orange |
115.0655 kHz |
|
The village of Aagotnes on Sotra Island in Western Norway was home a
Decca site from 1966 to 1999. The chain was closed down on Jan.17th,
1997 at 1200 noon. Stations in this chain used 1,200 watts of power.
Stavanger (Hodne) was closed down was January 22nd, 1997.
The Green slave of this chain was located on Shetland Island in close
physical proximity to the Green slave of the North Scottish chain 6C with
the Green carriers only 1.485 KHz apart. Can anyone comment as to why Decca
did it this way because it's the only example in the entire network?
More on the Norwegian Decca chains can be viewed
here .
SCOTLAND
HEBRIDEAN 8E
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Barra, Scotland |
Master |
85.635 kHz |
56º59'N, 07º25'W |
| Kentra Moss, Scotland |
Red |
114.180 kHz |
56º45'N, 05º49'W |
| Butt of Lewis, Scotland |
Green |
128.453 kHz |
58º30'N, 06º16'W |
| Dungloe, Ireland |
Purple |
71.363 kHz |
54º53'N, 08º23'W |
BACKGROUND
The Hebridean chain first transmitted test signals in Dec 1976, and
went on the air in 1977. It filled the last remaining gap in coverage around
the UK by providing coverage for the North and North West coasts of Ireland,
off the Hebrides and improved accuracy in the Minches. It was configured
for dual chain operation
Along with the Northumbrian chain, it used re-furbished thermionic
valve equipment bought back from the
USA. The USA had two experimental chains - one in California which
was used for airborne trials, and one around the Bahamas reputed to have
been used for submarine navigation. It is not certain which chain ended
up at which site.
The Hebridean chain shared transmitter locations with Dungloe of the
Irish chain, and the Butt of Lewis of the North Scottish chain, so only
two new sites were needed - Barra and Kentra. These stations were designed
to withstand the fierce winds and they looked like crofters houses.
They were built by the same Berwick-on-Tweed contractor that built the
Northumbrian stations to the same design. Transmitter sharing meant
synchronization of all these chains, which was done by using the Rubgy
time signal.
The Barra master was built during the glorious summer of 1976, when
the locals were amazed at the speed of construction. Having built the Northumbrian
stations previously had a lot to do with this. The stations of this chain
were all continuously manned because the economics were such that this
was a cheaper option than the capital cost of remotely controlled solid-state
stations. Of course, the shared stations were already manned and had the
full infrastructure in place.
Photos of the Hebridean chain can be viewed in this
section.
NORTH SCOTTISH 6C
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Kirkwall [a.k.a. Dounby], Scotland |
Master |
85.1850 kHz |
59º04'N, 03º15'W |
| Butt of Lewis, Scotland |
Red |
113.5800 kHz |
58º30'N, 06º15'W |
| Lerwick [a.k.a. Shetland], Scotland |
Green |
127.7775 kHz |
60º10'N, 01º 11'W |
| Peterhead, Scotland |
Purple |
70.9880 kHz |
57º31'N, 01º 51'W |
BACKGROUND
The Decca station in Dounby started transmitting from a group of wooden
huts on September 1, 1955. The base was set up by Ken King, who had been
running a station in the south of England. The first person to take charge
of running operations in Dounby was Harry Cordock along with Gordon Pirie
who lived in Stenness, and Davy Johnstone from Dounby. The last station
manager was Jim Anderson, who recalls those early days.
“I joined Decca in May 1956. It wasn't supposed to be officially open
until later, but the fishermen were in such a hurry that we opened it when
it was still manually controlled. We had to take readings and check other
things to make sure everything was all right. After that, you were just
waiting there in case anything went wrong. It was a case of diving at the
switches and doing something about it if anything happened.”
“Dounby [Kirkwall] was the North Scottish Master station, with ‘slave’
stations in Butt of Lewis, Peterhead and Shetland [Lerwick]. Jim added:
“I think there were four engineers to begin with, but it grew to five plus
a handyman when we moved into the new building in January 1958. The first
and second engineers lived on the premises. Harry Cordock was first engineer,
and Duncan Bell was second engineer. When Duncan returned to Edinburgh
he was replaced by Ken MacInnes from Stromness. That was when the transmission
system became reasonably automatic. You still had to be there, but you
could turn your back on it for a few seconds. It was a 12-hour shift system
we worked, and every 15 minutes we had to take readings off the receivers.
The figures were recorded in logs in triplicate, even though there was
a machine recording them as well.”
Tommy Mainland joined Decca in December 1966 in Dounby. He remembers
what it was like working a shift system, when living on the station. “When
I joined, we used to do 12 hours on a day shift, from 9 in the morning
till 9 at night. The next day, you went on at 9 at night and worked till
9 in the morning, and then you “allegedly” had two days off. I worked that
shift pattern for a while, and then eventually we changed that to one week
at 9 to 5, a week of 5 till midnight, and a week of midnight till 9 in
the morning. It ended up that when we got “sleeping” night watches, we
did 24 hours on, and 48 hours off.” Jim Anderson remarked: “Eventually
the station became more automated, we were able to sleep at nights.
George Grieve joined Decca at Peterhead in January 1967, one month later
than Tommy Mainland. George recalled the shift system he had to cope with.
“Peterhead was the ‘purple slave’ station. We just did 24 hours on,
48 hours off. But during the time off at Peterhead we were always very
busy doing the marine servicing side of it - with the navigators on the
fishing boats, which we also did up here, but not in such large numbers.
If they broke down when they were trawling, they would pull up their
nets, come ashore and get it fixed, rather than chance going without it.
We installed the equipment on board the boats and serviced it. It was 24
hours a day. They were paying for it, and they expected to get it. If the
system broke down at 3 o’clock in the morning, you were expected
to be there.”
The whole system became totally automated in January, 1994, and the
individual stations were left unattended except for maintenance work carried
out by a locally-based engineer. In Dounby’s case, that person was Jim
Anderson. “I've been on call 24 hours a day. I've had to go to the control
centre which is based at the lighthouse headquarters in Edinburgh, to do
shifts there from time to time. I always come out here once a week, although
the requirement was only once a quarter to do the maintenance, but I liked
to keep it in good order.”
The non-essential staff were kept on until the end of September, 1994
stripping out the entire supply of technical equipment from the main building,
and vacating the living quarters, to be replaced by a self-contained air-conditioned
aluminum clad cabin alongside, housing miniaturized equipment. Neither
Tommy Mainland nor George Grieve felt it hard to leave the Decca station
for the last time when they were made redundant at the end of September,
1994. Tommy commented: “It wasn't difficult, because we'd had so little
to do for the rest of that year. It seemed strange the building being there,
but doing nothing.”
In its heyday, Decca could promise a career for life, providing regular
training in electrical work and other aspects of the company's many interests.
Jim Anderson remembered those halcyon days.
“We had a Decca school which was at Brixham in Devon, and they
sent us on courses from time to time. The Admiralty weapons and communications
company Racal took over Decca in 1981 or so. It was said that they wanted
to acquire Decca’s radar company, rather than the avionics side of the
business. It was all going fine until a Danish company started making receivers
for fishing boats which operated with Decca’s navigation charts, but they
didn't pay any rental for using the system.
“A court battle followed, Decca lost the exclusivity, and that
started the beginning of the end. Income started to dwindle. Eventually,
the Ministry of Transport stepped in, and got the lighthouse authorities
to take us over. That would have been the early 1990s.”
Jim went on to talk about the final switch-off for the station. “The
equipment here is of no use to anybody else. That's the end of it. A skip
is coming and we'll throw everything out. We have to get rid of the condensers
in the coil house, and there's oil in them which has to be checked
before moving anything there. Alton Tait is taking over the cabin
and the engine, so we'll leave the control gear connected up, and
just disconnect our gear from it.”
Tuesday, April 4, 2000 marked the end of an era for post-war technology
in Orkney, with the complete shutdown of the Racal-Decca navigator
station in Dounby.
The Green slave of this chain was located in Lerwick in close physical
proximity to the Green slave of the Vestlands chain 0B with the Green carriers
only 1.485 KHz apart! Can anyone comment as to why Decca did it this way
because it's the only example in the entire network?
Select this link to see a map of the Scottish
chains.
Photos of the North Scottish Chain can
be seen here.
SOUTH AFRICA
BACKGROUND
In the late 1940's the South African Government conducted a series of
tests to determine the effects of the local conditions on the propagation
of Decca signals. George Hawker of Decca spent several months in the area
and much was learnt. Decca kept good contact with all concerned in South
Africa and this was rewarded with the building of five chains in the mid
and late '60's.
General Wilmott, the Supreme Commander of the South African Forces and
General Martin, the Head of the Air Force were closely involved in the
Navigator procurement while Colonel Broadhurst and an engineer named
Wadley conducted the initial trials. It was Wadley who developed the
communication receiver which established the technical base for much of
Racal Communications equipment.
The South Africa chains were heavily used by both coastal and helicopter
traffic. In the early 1970's, Decca established a separate company in South
Africa to sell and support it's products. Through expediency, this company
became virtually self-sufficient in it's operation and was very well run.
Much of the South African Defence Force relied upon Decca products for
navigation and communication.
A map of the South African chains,
photos and chain data can be viewed here.
SPAIN
Santiago Insua Fernandez, whose father was employed as a Decca
maintainer, provides a brief outline of the Spanish chains along with some
photos.
North-West Chain 4C
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| San Xoan de Rio, GALICIA |
Master |
83.8300 kHz |
42.383ºN, 07.283ºW |
| Noia, GALICIA * |
Red |
113.107 kHz |
42.733ºN, 08.917ºW |
| Boal, ASTURIAS |
Green |
127.245 kHz |
43.450ºN, 06.833ºW |
| Vitigudino, CASTILLA LEÓN |
Purple |
70.6920 kHz |
41.017ºN, 06.433ºW |
| * Lousame is the name of the nearest village to the former
4C Red station, but it's a village of only 100 habitants. The principal
village in the area is Noia (18,000 habitants) and this is the name that
is recorded in all official documents. |
Southern Chain 6A
This chain was designed to serve the narrow waters around Gibraltar
and the ports of Huelva and Algeciras. The master station was about 60
miles north of Malaga.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Setenil de las Bodegas, ANDALUCIA |
Master |
85.1750 kHz |
36.867ºN, 05.133ºW |
| Padul, ANDALUCIA (near Granada) |
Red |
113.5667 kHz |
37.033ºN, 03.683ºW |
| Los Barrios ANDALUCIA |
Green |
127.7625 kHz |
36.183ºN, 05.483ºW |
Rociana del Condado, ANDALUCIA
(near Seville) |
Purple |
70.9792 kHz |
37.300ºN, 06.600ºW |
BACKGROUND
The installation of Decca Navigator in Spain in 1977/78 was a joint
venture between The Decca Navigator Company and Marconi Español.
Both Spanish Chains had an effective range of 240 miles. All sites
used the 1880 series station equipment which was also designed for unattended
operation. System monitoring was based on a remote receiver at a small
mountain village called Olvera and the data was sent via microwave link
to the master station. Much of the ancillary equipment was made or purchased
by Marconi and they installed most of it. Once the chain was completed,
the Decca vessel, MV Navigator was used for some of the system trials
In Spain, the government decided to have manned Decca sites. The
personnel who maintained the Decca chains were employed by the Special
Public Corporation, an arm of the Spanish Public Works Ministry. Slave
stations had one dedicated maintainer while master stations had four people.
Most of the maintainers lived on the station properly along with their
families. In 1994, the Spanish Government announced that the Spanish Chains
will remain in service until the year 2000. One year later they closed
Decca and all the employees of the Spanish Chain were transferred to the
Spanish Public Ports. This semi-private corporation was called "Ente Publico
de Puertos del Estado Español ".
The North Spanish chain became well known as the one where a station
engineer froze to death while trying to reach the building during a winter
storm. He was found crouched behind a wall within sight of the buildings.
For photos and a map of the Spanish chains, select
this link.
STRAIT OF HORMUZ
Proposed in 1978, the chain was never built due to the Iranian revolution,
however the chain appears on a Decca document published in 1982. For additional
information and map select this link.
SWEDEN
Both the North and South Baltic chains were in Sweden.
North Baltic 4B
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Nynäshamn, Sweden |
Master |
84.825 kHz |
58°56’42.95”N 17°57’31.13”E |
| Åland Islands, Finland |
Red |
113.100 kHz |
60°07’12.43”N 19°49’29.08”E |
| Ar, Sweden |
Green |
127.238 kHz |
57°54’52.41”N 18°57’29.28”E |
| Björkvik, Sweden |
Purple |
70.688 kHz |
58°50’46.10”N 16°34’22.26”E |
The North Baltic chain was made operational in October 1957. Prior to
1970, the Red slave was located at Rådmansö, but it was moved
to Åland in 1970. Ar is a small village at the northwest tip of Gotland
Island.
South Baltic 0A
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Holmsjö, Sweden |
Master |
84.100 kHz |
56º 27' N, 15º 40' E (56.450ºN, 15.667ºE) |
| Burgsvik, Sweden |
Red |
112.133 kHz |
57º 03' N, 18º 15' E (55.400ºN, 14.183ºE) |
| Sandhammaren, Sweden |
Green |
126.150 kHz |
55º 24' N, 14º 11' E (57.017ºN, 18.250ºE) |
| ? |
Orange |
|
? |
Chain 0A opened as a multipulsechain but no information is available
regarding the Otange slave.
BOTHNIAN CHAINS
By the early 1960's, the old Swedish chain had become
the North and South Bosnian Chains.
The North Bothnian 5F chain consisted of
a master and two slave stations in Sweden while the third slave was in
Finland. It came into commercial service in June 1962.
.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Lövånger, Sweden |
Master |
85.095 kHz |
64°20’55.67”N 21°20’55.20”E |
| Gamla Karleby, Finland |
Red |
113.460 kHz |
63°51’51.36”N 23°10’58.24”E |
| Kallax, Sweden |
Green |
127.643 kHz |
65°31’45.86”N 22°04’08.01”E |
| Järnäs, Sweden |
Purple |
70.913 kHz |
63°28’46.29”N 19°39’13.41”E |
The entire
South Bothnian 8C chain was located
in Sweden. It came into commercial service in June 1962.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Njurunda, Sweden |
Master |
85.550 kHz |
62°16’47.55”N 17°25’31.13”E |
| Skutskär, Sweden |
Red |
114.067 kHz |
60°37’17.71”N 17°26’34.20”E |
| Järnäs, Sweden |
Green |
128.325 kHz |
63°28’46.29”N 19°39’13.41”E |
BACKGROUND
In 1974, it the Swedish government requested an upgrade for both the
North and South Bothnian chains which would give them Multipluse capability.
In addition, a new chain configuration was requested by the Board
of Shipping and Navigation of the Swedish Government. Decca carried out
some special development to provide a dual Slave Station with Type 1880
equipment to permit both chains to be controlled from a single remote Control
Station situated at the dual slave station.
The dual Station, comprised of the Purple Slave of the Northern
Chain and the Green Slave of the Southern Chain, only used a single main
antenna mast. This was the first time that a dual slave with double
tuned antenna had been built with Type 1880 equipment. It was also the
first example of two chains being controlled from a single Control Station
separate from the Master station of each.
The dual slave configuration was a late development in the system but
proved itself in terms of cost savings. The station still only had one
mast and coil house, but it was fed by two individual sets of transmitters,
one for each chain that it served. The station control room would thus
be equipped with two full sets of racks and transmitters. In the coil house,
a magic circuit of thyristors provided the tuning shift and circuit
snubbing for this to take place. Doug Sim , spent a whole day in the coil
house at Stirling trying to make the first one of these units work.
The Swedish Decca story is told in a book titled "Deccatiden i
Sverige 1947-2000" by Lars Malmquist. Translated: 'The Deccatime
in Sweden 1947-2000". Published by SMA, Norrköping, 3793-2000.
For a map of the North and South Bothnian chains, select
this link.
SKAGERRAK 10B
The Skagerrak chain was opened on June 2, 1967.
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Fjällbacka, Sweden |
Master |
85.9000 kHz |
58.517ºN, 11.300ºE |
| Jomfruland, Norway |
Red |
114.533 kHz |
58.867ºN, 09.600ºE |
| Vallda, Sweden |
Green |
128.8500 kHz |
57.483ºN, 11.950ºE |
| Årjäng, Sweden |
Purple |
71.5833 kHz |
59.350ºN, 12.183ºE |
UNITED ARAB EMIRATES
The Southern Persian Gulf Chain 1C was based in three
countries. Locations were:
| LOCATION |
DESIGNATION |
FREQ |
COORDINATES |
|
|
|
|
| Qarnain Island, United Arab Emirates |
Master |
84.285 kHz |
24º 56' 7"N, 52º50'59"E |
| Doha, Qatar |
Red |
112.380 kHz |
25º15'40"N, 51º33'54"E |
| Lavan Island, Iran. |
Green |
126.428 kHz |
26º47'25"N, 53º13'00"E |
| Ras Zubayyah, United Arab Emirates |
Purple |
70.238 kHz. |
24°20'N, 54°10'E |
BACKGROUND
Coverage was needed over virtually the whole of the Persian Gulf which
meant that several States had to be involved. Usually these States were
not agreeing with each other and often there were bitter rivalries and
unhappy memories of past events. No one State could possibly be responsible
for the whole of the Gulf.
Fortunately, Decca found a remarkably effective organization operating
lighthouses and beacons in the area. It was the Persian Gulf Lighting Service
at the time. It was operated by the major oil companies and so it was a
"natural" starting point for Decca to introduce the system.
Decca initiated discussions with the PGLS and the major oil companies
were deeply involved. Agreements were signed which led to a programme of
construction and operation under the most difficult conditions but the
end result was a reliable service. This continued until the military operations
in the North required the relocation of some of the stations and ultimately
their closure. The leading man in PGLS was Captain Webb and he was aided
by representatives from Shell and BP and included the late Tom Gaskell,
scientific adviser to the BP board.
It is believed that PGLS later changed their name to MENAS (Middle East
Navigation Aids Service). The two chains in the Persian Gulf were
operated by MENAS. In June 1973, that organization announced the upgrade
of the Decca chains to the Multipulse standard. Since the two chains
were originally installed in 1960-1961, the Multipulse system had
been developed in order to provide extended lane identification ranges,
particularly at night.
The existing Mk.V equipment at the seven transmitting stations was replaced
with Mk.10 Multipulse equipment That also also permit users to take full
advantage of the features provided in the new solid state Mk. 21 Decca
receiver which started to see service in the merchant marine.
Work on the conversion programme, which included moving the Master station
of the Southern chain a distance
of 12 miles from Das Island to Ouarnain Island, commenced on 1st March
1973 and was completed by year's end. The station was moved as the part
of the development of an Liquid Natural Gas terminal on Das Island.
To ensure that the Decca transmitting antenna did not pose a hazard
to the nearby air terminal while on Das Island, the standard 300 foot high
transmission tower was instead, broken down into a three, shorter masts.
This provided equivalent functionality and is the only known Decca chain
which used such an arrangement. The South Persian Gulf chain was probably
one of the few that had stations re-located due to unforeseen urban sprawl
On the new island, the three Decca engineers were the only inhabitants.
One day they were visited informally by Queen Elizabeth when the Royal
yacht Britannia anchored offshore and the Royal family picnicked on the
Decca island - a marvellous piece of true Decca folklore. To help break
the boredom, each Decca engineer took turns at throwing a party for the
other two.
The purple station was originally established on the beautiful beachfront
corniche in Abu Dhabi but was moved in 1974 to Ras Zubayyah in order to
facilitate hotel development. Ras Zubayyah was no more than a piece
of sand adjacent to the coast. Ras means inlet in Arabic. There was not
a living soul for 50 miles around when the station was first built. The
station did however, sport a nice swimming pool back in 1978,
so a few expats would come over have beer occassionally.
Chain 4F, for the Straits of Hormuz, was proposed but never built due
the political troubles in Iran after the fall of the Shah in 1979. One
Decca manual indicated that the chain was under construction in 1987 but
there is no proof of this.
A map of the Southern Persian Gulf
chain and some photos can be seen here.
UNITED STATES
AMB Experimental Chain 5C (Multipulse)
| LOCATION |
DESIGNATION |
FREQ |
|
|
|
| Yorktown Heights, NY |
Master |
85.0050 kHz |
| Yaphank, Long Island, NY |
Red |
113.3400 kHz |
| Newton, NJ |
Green |
127.5075 kHz |
| Red Hook, NY |
Purple |
70.8375 kHz |
BACKGROUND
On January 24, 1958, it was announced simultaneously in Washington and
London that the Air Modernization Board (AMB) had signed a contract with
the Decca Navigator Company's U.S. licencees , Bendix Pacific to provision
an evaluation Decca chain in the NYC area. The main purpose of the
chain is evaluation with respect to helicopter operations. New York
Airways, who operate scheduled helicopter service from the Idlewild International
Airport (now called JFK) to the Pan Am Building in the center of Manhattan.All
aircraft will carry a Decca Flight Log
The AMD was formed under the chairmanship of General E.R. Quesada as
one result of the Curtis Committee's Recommendations to President Eisenhower.
Quesada stressed that "the Decca System has been choosen because it is
the only one in a state or operational readiness". He also said that "the
pictorial presentation which Decca provides will enable pilots to navigate
with pin-point accuracy".
In another development, the United States Coast Guard experimented with
the Decca chain in the New York City area. If provided coverage to the
entrance and approaches to New York harbour and worked reliably out to
200 miles according to one user. An interesting comment is that during
the New York operation there was a major electrical power failure and the
City lost virtually all of its power and many of the emergency services
were not available. However, the Decca stations with their advanced emergency
power supply systems developed by Dougie Boycott continued without interruption.
There was also a chain set up in Georgia for the US Army at Huachuca.
Ernie Easter of Decca was instrumental in setting up this chain. It is
speculated that this chain was used to test the proposed application of
Decca in Vietnam and may also have been used as a training system for aircrew
since we know Decca was used in Vietnam.
California Chain (ID ?)
Decca Navigator Inc was incorporated in the State of California on 10/23/1963
under registration number 459735. A contract to build an experimental
type 820 chain near Los Angeles was signed in 1968. Evaluation commenced
on June 8, 1970 as noted in Decca Navigator Magazine, August 1970. One
of the big headaches for Decca was real estate and getting the masts to
fit the sites. Dan Arney, KN6DI, a former commercial pilot says that
"Los Angeles airport (LAX) area had Decca coverage for LA Airways.
I was also out on a fishing boat out of the Channel Islands near
Ventura and it was fitted with Decca."
