History of the Atlantic Cable & Undersea Communications
In September 1968 CS Retriever was sent to repair the SEACOM telephone coax cable that ran from Madang to Cairns, coincidentally I think it was part of the cable that had been laid by HMTS Monarch as a result of the SEACOM Stage 2 sea bed survey we did in mid to late November 1964 when I was on the CS Mercury. Mercury had laid the first couple of sections of the SEACOM cable, the first leg from Singapore to Jesselton (now Kota Kinabalu, Malaysia) in July 1964, and the second leg from Jesselton to Hong Kong in early November 1964 in winds of force 8/9, rough seas and a heavy swell!
For the record, we laid 856 nautical miles of lightweight coax, 334 nautical miles of armoured cable and 57 repeaters for the first leg at an average speed of approx 4.5 knots, and at least 600 nautical miles of lightweight and 66 nautical miles of armoured for the second leg - average speed not known but I suspect it was much lower due to the filthy weather. The number of repeaters for the second leg is not recorded in the Engineer-in-Chief’s Daily Report of Ships’ Movements. As mentioned, the Monarch laid the remainder of the SEACOM cable, finishing it in 1967.
The picture shows lightweight coax cable construction; the outside diameter of the cable was one inch – much less than people would think.
During the survey we had spent ages (it seemed like an eternity) slowly steaming along with the precision echo sounder working overtime and occasionally dropping a very new, experimental camera to the sea bed to see what was down there. The pictures we got back weren’t very exciting, just mud and a few strange creatures that weren’t very distinct in the grainy, black and white photographs (no sophisticated remote controlled video gear in those days!).
Anyway – getting back to the repair, the water in that area is extremely deep, some miles I believe. The accepted technique for cable repair at that time was to steam to the approximate position of the break (they knew roughly where it was damaged/broken because shore based engineers measured the resistance of seawater from both shore ends and calculated the distances to the break using a standard reference for the conductivity of sea water for the region).
Then, as the cable laying process was always very precisely charted, we knew that the cable would be lying in a certain orientation and along a certain track, so when we were at right angles to the cable position we slowly steamed back and forth, dragging a large grapnel, until we hooked something. For this repair, it took at least a day to lower the grapnel because of the depth of water and a bit longer (because of the weight of grapnel cable and whatever it was bringing up) to raise it - I think maybe a day and a night. The whole exercise of fishing for cable, testing and completing the repair did actually take five or six days and nights.
We eventually hooked the cable and brought it back on board for the cable engineers to do their stuff. The cable was cut, signals were sent down both cut bits and any response was noted – as is usual, one piece of cable responded, indicating that it was intact back to whichever shore station it was. The useless piece was discarded over the side if it was too short to be of any use for a future repair (cable was valuable stuff - about a Pound Sterling a foot in those days I was told) and the good piece was thoroughly tested, sealed and carefully dropped over the side attached to an extremely large buoy - I'm guessing, so I may be wrong, but I think those buoys were around 20 feet high (excluding the mast and associated paraphernalia) and absolutely huge around the middle.
The grappling and cable cutting/testing process was repeated until we had the other part that was connected to the second shore station. We then joined a new piece of cable to the good piece and slowly steamed back, paying out cable as we went, to where we had left the other end bobbing up and down on the end of the large buoy.
Except, when we got to where the buoy had been laid.... it wasn't there!
Even in those days, cable ships carried the world's best in the way of navigation equipment and could steam to any part of the world and be at any given spot on the ocean to within a very small margin of error - I forget what it was but it was something in the order of a couple of hundred yards I think. So, where was the buoy? The navigation was spot on and the buoy had a large radar reflector, and lights too I think, so we were hardly likely to not see the blasted thing!
Well, nothing for it but to buoy off the new piece of cable we had just laid and grapple for the cable again.
A couple of days later we found it and began the laborious process of bringing it to the surface. After the usual cutting and testing we had a live piece and a stone dead piece, but out of curiosity we didn't discard the dead piece and slowly reeled it in.
When we got to the end of the cable, much to our astonishment, what did we see, but the buoy - squashed as flat as a pancake!! The weight of cable (due to the immense depth of water) had eventually proved too much for the buoy to hold and so down she went, with the pressure getting more and more until the poor thing had imploded.
You should have seen it! What an eye opener THAT was! Unfortunately I didn't take any pictures of it, but I can still see it in my mind's eye, it had hit the bottom of the ocean with the speed of an express train and was severely battered and covered in mud as well as being flattened, with the huge split and jagged edges showing where it had surrendered to the deep.
So, why did the buoy sink? We never did find out. Suggestions put forward included a slow leak in the buoy, an earthquake on the sea floor – causing rocks to fall on the cable, or a submarine catching the suspended cable. Your guess is as good as anyone’s.
Note: Although I have used the terms “steam”, “steaming” and “steamed” it should be noted that they are the traditional way to describe a ship’s progress, regardless of motive power – sailing ships excepted of course. CS Mercury and CS Retriever were both diesel electric ships.
Last revised: 11 October, 2018