Anatomy Of A Deep Sea Fibre Optic Cable
On the left is a deep sea fibre optic cable. It consists of fibre pairs, ranging from two to 24, placed in a hermetically sealed stainless steel chamber surrounded by closely packed steel wires, then a copper power conductor layer, and finally a polyethylene sheath. The diameter is usually just 17 millimeters or 1.7 centimeters. A standard home garden hose in the US is about 16 mm. Deep sea cables must be thin because the cable's length can be as much as 12,000 kilometers. It would be very difficult to transport and lay a thick cable over long distances. Deep sea cables have always been thin. The engineering challenge is to make it thin and highly reliable. Note that in shallow waters, usually defined as either 2,000 or 1,000 meters deep and less, the cables may have external armor in the form of steel wires wrapped around the polyethylene sheath. This protects against fishing and anchors. The cable sample on the right is armored. An armored cable typically has one to three sets o...