Umbilical cable refers to a technology that delivers vital consumables, signals, or energy through a hose or line. With a name derived from a mother's umbilical cord, umbilical cable can be any cable that carries a medium of vital importance for survival or control. It can describe numerous types of cable in different areas — for example, undersea transmission lines or the air lines supplying oxygen to divers from a boat. Other contexts can include uses in space suits or in the operation of remote-controlled vehicles.
Early examples of umbilical cable include the first forays into underwater diving in the 16th century. At that time, diving bells connected by umbilicals carried surface air beneath the water. Through various incarnations, and with the advent of military technical developments, modern divers came to depend on self-contained underwater breathing apparatus (SCUBA) technology and rebreathers to liberate themselves from their bases. The modern equivalent to the antiquated hookah system is called sport surface-supplied compressed air (SSSA), which uses surface-supplied air compressors to deliver air through hoses and regulators to recreational divers.
Similarly, umbilical cables delivered life-giving air and temperature/humidity controls via cable to early astronauts. These functions came to be self-contained in later spacesuits. Like the diver, astronauts became liberated from their bases for extended periods and distances.
Three-part diving umbilical cables often consist of a grouping of gas, communications, and depth-indicating hoses called pneumos. Pneumos are open hoses that connect to pressure gauges on a boat or dock to allow supervisors to monitor a diver's depth. Additional hoses to a diving umbilical may include hot water supply and video cable. This permits live video feeds from a diver's wearable camera. Divers must be aware of catching their umbilicals on obstructions that might damage the cables and leave them stranded.
Subsea umbilical cables may carry chemicals and oil, or deliver telecommunications signals through heavily shielded fiber optic lines. Other armored umbilicals are designed for load-bearing weights, with abrasion-resistant coverings. These may be used as tethers or tow cables, and be rated for undersea temperature variations and tough conditions.
Sea-resistant, lightweight umbilical cable may consist of cable groupings that may consist of electrical lines, thermocouplers, rubber, or polyvinyl lines for the flow of gases, electrical currents, and other transmission materials. Umbilical cables deliver remote-control capability to undersea remote-operated vehicles, which may include video transmission lines in addition to electronics control. Umbilical cable continues to provide reliable and vital support into the new frontiers of many industries.