The Atlantic Cable website often receives requests for historical data on signalling speed and traffic capacity of long distance cables, so I've summarized here some improvements in cables over the last 150 years. The majority of cables listed are Atlantic crossings to give consistency to the results.
This page also provides further technical details of the "Telephone Era", the period that begins in 1956 with the opening of the first voice cable across the Atlantic, TAT-1, and ends in 1988 with the laying of TAT-8, the first digital fibre optic Atlantic cable.
| Cable |
Year |
Speed or Capacity |
| Atlantic, Ireland-Newfoundland |
1858 |
A few words per hour |
| Atlantic, Ireland-Newfoundland |
1866 |
6 - 8 words per minute |
| Long cables with automatic transmitting equipment |
1898 |
40 words per minute |
| Newfoundland-Azores |
1928 |
2,500 characters per minute (~400 wpm) |
Atlantic, TAT-1
(first repeatered cable) |
1956 |
36 telephone channels |
| Atlantic, TAT-2 |
1959 |
48 telephone channels |
| Atlantic, CANTAT |
1961 |
80 telephone channels |
| Atlantic, TAT-3 |
1963 |
138 telephone channels |
| Atlantic, TAT-4 |
1965 |
138 telephone channels |
| Atlantic, TAT-5 |
1970 |
845 telephone channels |
| Atlantic, TAT-6 |
1976 |
4,000 telephone channels |
Note: In 1978, before the inauguration of TAT-7, an article in the Times noted that:
“More than half of all international telephone calls between Britain and the rest of the world go by undersea communications circuits.”
The rest were transmitted by satellite, but with the advent in 1988 of TAT-8, the first transatlantic fiber optic cable, the balance moved rapidly to cable. Since then, satellite has played only a relatively minor role, as the article went on to predict.
[Pearce Wright. “Cable and satellite systems maintain rivalry.” Times (London, England) 4 Apr. 1978: IV.] |
| Atlantic, TAT-7. The last analogue cable |
1983 |
4,000 telephone channels |
| Atlantic, TAT-8. The first fiber-optic digital cable |
1988 |
280 Mbit/s (40,000 telephone channels) |
| Atlantic, TAT-9 |
1992 |
2 x 565 Mbit/s (each 80,000 telephone channels equivalent) |
| Atlantic, TAT-10 |
1992 |
2 x 565 Mbit/s |
| Atlantic, TAT-11 |
1993 |
2 x 565 Mbit/s |
| Atlantic, TAT-12/13 |
1996 |
2 x 5 Gbit/s |
| Atlantic, TAT-14 |
2001 |
4 x 16 x 10 Gbit/s, 640 Gbit/s system capacity (9,700,000 telephone channels equivalent).
Note: TAT-14 has four fiber pairs, each carrying 16 wavelengths. Each wavelength carries a 9.6 (nominally 10) G signal, giving a 640 Gbit/s total capacity. |
| Atlantic, VSNL (TGN) |
2001 |
2 x 2,520 Gbit/s |
| Hibernia Atlantic (cable commissioned in 2001 and partially upgraded in 2007) |
2007 |
10 Gbit/s on transatlantic section, 40 Gbit/s from Boston to Nova Scotia.
System capacity 1.9Tb/s, 7.68Tb/s on upgraded section |
| Atlantic, GTT Express (formerly Hibernia Express) |
2015 |
100 Gb/s x 100 wavelengths. Maximum capacity 53 Tb/s |
Stewart Ash has created this detailed table of analogue transatlantic submarine cables in the “Telephone Era,” 1956 to 1988.
This 32-year period begins with the first repeatered telephone cable, TAT-1 in 1956, and ends with the laying of TAT-8 in 1988, the first digital fibre optic cable across the Atlantic.
Year |
System |
Terminal A |
Length |
Terminal B |
Cable |
Repeaters |
Capacity |
1956 |
TAT-1 A & B |
Oban, Scotland |
A-B 1,945nm B-A 1,942nm |
Clarenville, Canada |
0.620" DA: AB.
SA: B, C, D |
A-B 51 B-A 51 Spacing
38nm |
36 x 4KHz Channels |
1959 |
TAT- 2 A & B |
Penmarch, France |
A-B 2,209nm B-A
2,194nm |
Clarenville, Canada |
0.620" DA:
AB. SA: B, C, D |
A-B 57 B-A 57 Spacing
38nm |
48 x 4KHz Channels |
1961 |
CANTAT |
Oban, Scotland |
2,073nm |
Corner Brook, Canada |
0.620" Armour 0.990" LW |
90
Spacing 26nm |
60 x 4KHz Channels |
1963 |
TAT-3 |
Widemouth Bay, Cornwall |
3,518nm |
Tuckerton, New Jersey |
0.620" Armour
0.990" LW |
182
Spacing 20nm |
138 x 3KHz Channels |
1965 |
TAT-4 |
Tuckerton, New Jersey |
3,599nm |
St Hilaire, France |
0.620" Armour 0.990" LW |
186
Spacing 20nm |
138 x 3KHz Channels |
1970 |
TAT-5 |
Green Hill, Rhode
Island |
3,461nm |
Conil Cadiz, Spain |
0.935" Armour 1.47" LW |
361
Spacing 10nm |
720 x 3KHz Channels |
1974 |
CANTAT-2 |
Widemouth Bay, Cornwall |
2,805nm |
Halifax, Nova Scotia,
Canada |
0.935" Armour 1.47" LW |
473
Spacing 6.0nm |
1840 x 3KHz Channels |
1976 |
TAT-6 |
Green Hill, Rhode
Island |
3,396nm |
St Hilaire, France |
1.7" Armour
& LW |
694
Spacing 5.1nm |
4,000 x 3KHz Channels |
1978 |
PENCAN 3 # |
Las Palmas, Canary Is. |
743nm |
Chipiona Cadiz, Spain |
1,47" Armour
& LW |
270
Spacing 2.75nm |
5,520 x 3KHz Channels |
1983 |
TAT-7 |
Tuckerton, New Jersey |
3,296nm |
Porthcurno, Cornwall |
1.7" Armour
& LW |
664
Spacing 5.1nm |
4,246 x 3KHz Channels |
| The end of the analogue telephone cable era and the beginning of the digital era |
1988 |
TAT-8 A-B-C |
Tuckerton, New Jersey |
6,381Km |
Widemouth, Cornwall |
21mm SL & NL
Armour & LW |
87 + 13
Spacing 67 + 40 Km |
7,560 x 64Kbits/s Channels |
1988 |
TAT-8 A-B-D |
Tuckerton, New Jersey |
6,167Km |
Penmarch, France |
21 mm SL & S280 Armour
& LW |
87 + 8
Spacing 67 + 44 Km |
7,560 x 64Kbits/s Channels |
# PENCAN 3 was an STC 45MHz system and was equalised to provide the highest telephone circuit carrying cable of the Telephone Era. The repeater span inhibited its being used as a transoceanic system. TAT-6 & TAT-7 were AT&T’s 35MHz systems.
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