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A BRIEF HISTORY OF SUBMARINE RADIO COMMUNICATION

Dr. Monroe Jones is an Industrial Psychologist consulting in Organizational Development and Labor Relations. He is also the Director of the Submarine Research Center in Bangor, Washington. He qualified in Submarines twice: as an enlisted man on STERLET and as an Officer on Sf RAGO. He is a frequent contributor to THE SUBMARINE REVIEW.

Captain Baker served as a Radioman in four submarines making RMC(SS) in THEODORE ROOSEVELT before being commissioned as an LDO. He continued in submarine communications billets along with a seven-year tour at the White House. As a Captain he commanded NA VCOMSTA Puget Sound and NA VCAMSEASTPA C. He retired after forty years of service.

The latter half of the 20th Century was a technological race between competing hardware and software companies in computers and telecommunications. The Navy kept up with the pace of instant communications and applied the research to Cold War demands.

As vacuum tubes gave way to transistors in the 1960s and finally to micro-chip circuits in the 1970s and 80s the use of Morse Code in submarines dwindled. In the mid 1960s, CW was largely replaced by radio tele-type. The crypto graphically secure JASON system used the KW-37 machine. Submarine shore to ship communication called Fox was transmitted six times over a twelve-hour period. A submarine could rise to periscope depth and copy the Fox transmission for that day at any of the scheduled transmissions. Submarine Fox was transmitted from the ComSub-Pac transmitter at Pearl Harbor to boats operating in the Pacific and ComSubLant at Norfolk sent its Fox messages to boats in the Atlantic.

Submarine VLF reception was best achieved by a trailing antenna, although multi and single loop antennas were also mounted on American submarines. The trailing antenna was a single strand copper wire in a myelin insulating sheath wound onto a reel. At the bitter end of the antenna wire was a steel weight, which kept the antenna taut and acted as its ground. The very low frequency loop was formed by the antenna wire and the steel grounding weight, which radiated RF waves through the sea and to receptors on the submarine’s hull. The reel was kept in a trunk housed in the sail and accessible from the control room. When ready to receive, the trunk was opened and the wire was extended by threading it through an orifice in the trunk. American submarines normally carried three spools of antenna. This redundancy reflected the delicate nature of the antenna. If the diving officer used too large a down angle the ship’s screws rose about the center of gravity and parted the trailing antenna. In addition, fishing boats and their rigs occasionally parted the wire. Splicing kits were also kept on submarines and could be used when an antenna was damaged in a recovery. Submarines using this type of antenna continue to experience similar difficulties.

Radiomen in submarines were normally assigned to encrypt and decrypt messages up to and including Secret. Top Secret was normally reserved for officers who crammed themselves into the small radio space to do their work. Neither officers nor radiomen liked the idea and it was inevitable that radiomen would sometimes decrypt incoming Top Secret messages. This came to the Navy’s attention and modifications were made. Tommy Robinson recalls, “Back in the early I 960s someone in a high pay grade decided that submarines should have their own crypto rooms. Radiomen performed the majority of crypto operations, but occasionally an “Officer Eyes Only” message would require an officer’s attention; normally the communications or operations officer. But the orders came down and during overhaul of USS NAUTILUS (SSN-571) in 1964 we radiomen became proud owners of a crypto room. Physical space was limited in our submarine, especially in radio. Our radio space, located on the starboard side of the control room, was a narrow passageway with transmitters and other equipment against the pressure hull and two CW stations and receivers inboard. A few feet of space inside the room, just forward of the entry door from control, was partitioned and a heavy, metal vault door installed. The result was a metal closet about the size of the officers’ head. As I recall, our crypto room contained a safe for registered publications, a chair and KLB-47 crypto machine for encrypting and decrypting messages. A skinny person could just manage to squeeze into the chair with his knees knocking against the machine. The vault door had to be shut and locked from inside the vault. Sea trials followed completion of the overhaul at NSY, Portsmouth, New Hampshire, and we were happy to be at sea. As NAUTILUS submerged beyond 200 feet depth and the pressure hull contracted, our crypto vault door jammed shut, not to be opened until the boat ascended into shallower water less than 200 feet. Although we were aware of the problem, we failed to mention it to any officer. The first time our crypto vault was used by an officer, he emerged after a lengthy stay to remark how stuffy it was in there. Apparently, he thought the problem was of his own making. It took a few self-doubting officers before one reported the problem to the Executive Officer. We radiomen remained silent on the issue.”

Fox and all two-way submarine communication were en-crypted into five letter code groups. The length of transmissions and frequency of them was kept constant by the insertion of a parallel running tape that interspersed nonsense words or publicly released news, whichever best filled the time equalization need.

In Japan during the 1960s, VLF frequency transmissions from American communication facilities continued to use CW. The transmitter was of German Telefunken make that used a rotary generator AC power output. Whereas three-element vacuum tube power output produced a sharp character, the Telefunken produced a character trailing edge that smeared into the next character. Copying the blurred transmission was difficult and resulted in much ship-board anxiety as encrypted messages were riddled with spurious letters.

When tele-type communication replaced CW, radiomen had to learn the new equipment and procedures quickly. Often, this meant on-the-job training and it was natural that a few mistakes might be made, even by seasoned personnel. Most were of little consequence; such as the following: Submarine scheduled broadcasts were transmitted every two hours and the period of silence between the broadcasts was partially filled with repeated Victors. This was for tuning purposes and the dit-dit-dit-dah was familiar to all submarine radio operators. Of course, the transmission was by tape, which contained holes and slits for the automatic equipment. A radioman inserted the tape backwards and the resulting transmission was an endless stream of Bakers; dah-dit-dit-dit. Radiomen aboard submarines at sea immediately visualized the mistake and chuckled at the prospect of some poor shore-based lad who would shortly be one stripe lighter.

Submarines depended more and more on teleprinter circuits and communications finally became computerized in both receiving and transmitting. Accordingly, the rate of Radioman lost its meaning and was dropped from the Navy’s list of ratings. It eventually became a specialty of the electronic technician rate.

During the early 1960s, the Navy hastily developed an air-to-submarine communication concept. Rear Admiral Bernard Roeder explained the concept to Lieutenant Jerry 0. Tuttle. He ended his explanation by ordering the Lieutenant to, “Take charge and move out.” Accordingly, the project became known as TACAMO, an acronym carrying the Admiral’s intent. Essentially, the concept was an integration of a continuous airborne VLF transmitter, housed in a variety of KC-130 Hercules aircraft, and a deep submergence VLF receiver in American submarines. An aircraft could be alerted to send a VLF trigger message to a deeply submerged boat, which could then rise to a more shallow depth for specific missile launch instructions. Both the aircraft and submarine trailed very long external antennas. In the Pacific the aircraft were stationed at Barber’ s Point, Oahu and on Guam. This system remained in effect until other communication options and the nature of the Cold War diminished the importance of the project. It was, in part, augmented in the late 1970s and early 1980s by the introduction of Seafarer, originally called Sanguine. The project called for an enormous ELF transmitter that would cost more than $23.7 million dollars. It was to be installed under Lake Michigan. Environmentalists succeeded in killing the bill, but the project was retained and later built at two other locations, Clam Lake, Wisconsin and Republic, Michigan, a separation of 148 miles. The two simultaneously keyed transmitters used a signal in the 40-80 Hertz range. The giant ELF transmitters were deactivated when the Cold War ended and the need for a bell ringer transmission was no longer needed. The concept was replaced by another R&D project called NAVSTAR. This concept involved the imposition of communication capability in existing intelligence satellites.

In 1998 the Defense Advanced Research Projects Agency (DARPA) sponsored an extensive and objective study of future submarine concepts. The DARPA report stressed the need for improved connectivity-the ability to communicate effectively. As a result, the Virginia class submarines, then on the drawing boards, were to be equipped with the latest VLF long-range radio wave reception at operational depths and speeds.

VLF and LF broadcasts operate in a frequency range from 14 to 60 kiloHertz. They are transmitted from six high-powered VLF multi-channel sites and seven LF multi-channel sites located world wide. Messages received from ComSubPac and ComSubLant make up the Integrated Submarine Automated Broadcast Processor System which emits a super-encrypted continuous signal. This sequence of messages normally lasts two hours. Signal clarity has been maintained by expanding the band-width using multiple, simultaneous, fiber-optic conductors. The system is called Clarinet Verdin. This description of the shore-to-ship/ship-to-shore transmission methodology is abbreviated and the actual process is more complicated. Submarines at sea have at their disposal satellite assisted communication called Submarine Satellite Information Exchange System or SSIXS. This program provides UHF SA TCOM broadcasts formed by the SSIXS computer operators at each of the submarine broadcasting stations. The Navy FL TSA T, satellite system, has been replaced by the MILSA TCOM or military satellite communication system, but its service remains the same. Navy communication systems with their attendant computers and satellites require information transfer and processing that are quick, reliable, easy to manipulate, and automated. The amount of technical support for such a system and its attendant cost is staggering when compared to the relatively simple system used in the Second World War.

The radio space in a modern Fast Attack or FBM submarine consists of several computers linked to satellites. Some boats still retain a teletype machine, but gone are the days of Morse Code.

For all practical purposes the difficulties of submarine radio transmission and receipt are currently such that the submarine must act as an independent body accepting information from shore installations on a schedule and transmitting information as needed on a very infrequent basis.

The journal, SUBMARINE REVIEW carried the following, “The U.S. currently has superior connectivity with its deployed submarines and this connectivity will get even better as recently approved developments are introduced to the fleet. However, as our experience in the area of submarine quieting has demonstrated, those faint noises heard in our baffles are potential adversaries, with far more to gain from an operational sense, improving their connectivity.”

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