Elaborations in the Big Networks

The big terminals of the Integrated Wideband Communications System, the huge antenna arrays, the transmitting and receiving equipment aligned row after row, the humidity-free, temperature-controlled buildings, surrounded by stacks of sandbags and revetments, the enormous, deafening diesel generators for electrical power, the hundreds of circuits constituting the Defense Communications System that laced Vietnam and Thailand-all of this would have been useless without the facilities at every site that provided the switching, or "breakout," of the individual circuits to form the myriad voice, teletype, and data networks that served the customer. The fact that a 240-channel "pipe" existed between two sites was meaningless to the combat commander who could not send a message or place a phone call between those two sites because the switches were not yet completed. The signal planners, therefore, had far more to do than just design the fixed wideband system. Concurrently with fixed-system planning and installation, efforts were being strongly directed toward improving both the telephone and message-switching service in Vietnam, where the rapid buildup had created havoc with the already overloaded military communications facilities.

The Growing Telephone System

During the 1965 buildup of U.S. troops in Vietnam, telephone systems sprang up wherever headquarters, base camps, logistics centers, and air bases were established. Originally each system was operator oriented, requiring the users to work through a manual switchboard to place a call. Such a slow inefficient system was a natural consequence of the rapid military buildup. Naturally when the 1st Signal Brigade was activated, telephone switching improvement stood high on the list of things to be done. At the outset the top requirement was meeting the needs of the Capital Military District in the Saigon area. As was pointed out previously, the evolution of telephone service in this area consisted of many manual


Photograph: Test Board In One Of The Many Dial Telephone Exchanges In Vietnam


switchboards, some consolidation, and then dial service. The telephone switch upgrade program was not confined to the Saigon area. The process of replacing older, manual equipment with newer dial equipment in the Capital Military District set a pattern that was followed throughout Vietnam, and applied to military encampments throughout Southeast Asia. As the big manual switch­boards were replaced in the Saigon area, they were moved to outlying camps to replace the smaller combat switchboards. Similarly, as three 600-line, van-mounted dial exchanges were replaced by fixed, commercial ones in the Capital Military District, the vans were sent out to field camps to replace manual switchboards.

To solve the immediate problems of longdistance telephone service in Vietnam, temporary arrangements were made in late 1966 and early 1967, pending the eventual installation of direct distance dialing switches. Six long-distance manual switching centers, employing large, nine-position manual switchboards mounted in vans, were established in Vietnam. Along with Saigon's long-distance switchboard the network by April 1967 was made up


of long-distance switchboards at Da Nang, Qui Nhon, Pleiku, Nha Trang, and Can Tho. This interim long-distance system remained the primary means of communication for general users until well into 1969, when the direct distance dialing system became operational.

Installation of dial telephone exchanges in the north mean­while occupied the 1st Signal Brigade's Telephone Management Agency, as well as civilians working for contractors. By the end of 1966, fixed automatic dial exchanges were scheduled for installation at fifteen different locations in Vietnam. The first conversion to a fixed-plant Army dial telephone exchange was at General Westmoreland's headquarters in January 1967. By the end of the year, eleven of the fifteen fixed-plant dial exchanges were operational. Counting all the military services, there was a total of twenty-nine fixed-plant dial central offices with over 34,000 lines in operation in Vietnam by the end of 1967.

Record Traffic: Message and Data

Another important communications network that received much attention during this period was the record or the printed message and recorded data traffic network. Use of the teletypewriter was, of course, the older method and the standby for record or printed message communications. It continued to serve as a back­bone of communications into and out of the war zone, and within Vietnam as well, especially for classified information.

Along with the message system employing manual tape relay, data communications were rapidly developing in Southeast Asia, equaling and eventually exceeding the standard teletype operation. An Automatic Digital Network which could process both message (teletypewriter) and data traffic was planned and approved by the Department of Defense in 1965. Automatic switching centers were to be established at Phu Lam and Nha Trang. Together, these two centers, each with a 100-line termination capability, were to fulfill an original requirement for 130 U.S. subscribers, with a capacity of 750,000 standard-length messages per day. This capacity represented a two-fold increase over the existing manual relay network's capability.

A number of months elapsed and millions of messages were passed over the manual systems, however, before communicators in Vietnam enjoyed the benefits of the automatic network. Because of the growth in traffic volume on the general-user message network as troop buildups and wartime activities increased, the major relay


Photograph: Signalmen Transmitting Message At Manual Tape Relay Center


at Nha Trang was upgraded to a 22-line fixed installation in April 1966, and the capability of the Phu Lam facility was expanded by upgrading it to seventy-two lines by the end of that year. To handle the increased traffic in the north, a third relay facility, mounted in vans, was activated at DA Nang in the I Corps Tactical Zone in December 1966. It was at this facility that two tape relay vans were destroyed by enemy action in February 1967. The DA Nang relay station was subsequently upgraded to a 48-line fixed installation and put to use in December 1967. The signal brigade commander, General Terry, made the following comments in his letter of 21 December 1966 to Major General Richard J. Meyer, commander of the Strategic Communications Command, regarding the first DA Nang transportable relay:

The cutover of DA Nang tape relay went extremely well. Traffic was a little under 5,000 [messages] yesterday. The impact on the load at Nha Trang was also apparent since Nha Trang dropped to around


12,000. Now, if we can keep the priority on the completion of the Class IV [fixed] projects, both at Nha Trang and DA Nang, we should be able to stay ahead of the message business.

These three facilities, linked together by the wideband communications system, were capable of relaying common-user message traffic between each other, as well as from major relays outside Vietnam. In addition, the three facilities were connected to minor message relays and to area communications centers. Daily traffic volume handled by all three major facilities averaged up to 70,000 messages in late 1967.

One of the most significant problems encountered in message switching in Vietnam was the abnormal amount of traffic using high-precedence indicators. The rapid growth in traffic resulted in completely distorted precedence distribution, in which up to 50 percent of all traffic was classed as "Immediate" or "Flash." The Joint Chiefs of Staff found it necessary to adopt a "Superflash" category in order to make sure that the real "Flash" action was properly disseminated. General Van Harlingen, 1st Signal Brigade commander from mid-1967 until February 1969, noted in his final debriefing report that, as a result of the burgeoning of message traffic, there was a slowdown in the delivery of messages; and a situation had developed in which there was constant danger of losing messages. Such losses were most likely to occur during equipment breakdowns in the overworked relay centers, and led to huge backlogs or pileups of messages. During periods of heavy backlog, even meticulous attention to procedures did not always prevent errors resulting in loss. And a lost message is considered, and rightly so, one of the most grievous sins in the communications-electronics community.

The requirements for data services in Southeast Asia followed, to a large extent, the growth of supply activities in that area; and, as the logistics system began to take shape, so did the capability to provide data communications improve. At the beginning of 1966, the only data relay in Vietnam was at the Phu Lam facility. This data relay had been established to provide limited service for urgently needed general-user digital data traffic. The majority of the circuits in Vietnam that were connected to the Phu Lam Noii-Automatic Relay Center could handle only ten data cards per minute, a rate that was intolerably slow to both the subscriber and the communicator and totally incapable of satisfying the growing data requirements.

Consequently, while the automatic digital switching centers destined for Vietnam were being developed and produced under


government contract, upgrades and extensions of the existing manual data relay system were in progress. The Phu Lam Non-Automatic Relay Center was upgraded by mid-1967. Circuits with a capacity of passing 200 cards per minute were connected with automatic switching centers in the continental United States, Hawaii, and the Philippines, as well as 100-cards-per-minute circuits to ten manual data centers in Vietnam. A second manual data relay, at Nha Trang, was cut to traffic in August 1967. Combined, these two facilities of the 1st Signal Brigade handled an average of 830,000 data cards per day. Although the non-automatic relay centers provided some relief for the three major tape message relays in handling their high volume of traffic, the equipment was still manually operated, thus requiring a large number of operators, and causing excessive handling time and a high rate of error. Unfortunately the message and data situation would not be rectified until the Automatic Digital Network was installed in Vietnam in mid­1968.

The Secure Voice Network

By mid-1967 still another communications improvement was being made in Southeast Asia by the Army and the 1st Signal Brigade. The recently developed and highly sophisticated Automatic Secure Voice Communications System was being installed in the Defense Communications System to serve not only Vietnam and Thailand, but also the armed services throughout the world. This system, a vital military requirement, took a considerable amount of time and effort to develop, for the feat involved more than the scrambling of voice impulses prior to transmission, a technique used to a limited degree during World War II. It was necessary to develop compact equipment that could be widely used, either in a spacious military office or in the dusty hot tent of a combat commander in a war zone.

A less sophisticated predecessor to this secure voice system, the "Talk Quick" system developed by the Navy, had been used in Vietnam since late 1965. Automatic Secure Voice System implementation, to replace "Talk Quick," had been planned in several phases. Phase I provided for 200 secure voice subscribers in Vietnam. On 17 July 1967 the first element of the Vietnam portion of the Automatic Secure Voice System became operational - an automatic dial exchange serving fifty secure voice subscribers in Saigon. Installation of the remaining 150 subscriber lines and attendant small manual switching centers serving all of Vietnam was planned for early 1968. This sophisticated equipment, although it satisfied


Photograph: Transmitting Data Cards At Non-Automatic Data Relay Center


operational needs, required much patience and training to use and maintain.

All of these networks, the telephone, the record message and data, and the secure voice networks, were built and improved during 1966 and 1967. It was not until 1968, and in some cases 1969, that they were completed.

Space Age Communications

Communications between Southeast Asia and the rest of the world received another boost during the period 1966-1967. U.S. Army communicators, in conjunction with the National Aeronautics and Space Administration, had devoted the past several years to improving and refining the embryonic art of satellite communications. Although limited satellite communications had existed in Vietnam and Thailand since 1964, a much more reliable system with greater capacity was required. In January 1966 the Defense Communications Agency published a plan to give communications


satellites a larger role in support of the war effort. Thirty-two satellite communications paths were planned between Southeast Asia, Hawaii, and the continental United States. These paths were divided between two satellite communications systems, the Initial Defense Communications Satellite System and the commercial system of the Communications Satellite Corporation.

The Initial Defense Communications Satellite System called for developing and launching a score of satellites to serve fourteen earth terminals. The satellites were placed in random distribution, in near-synchronous equatorial orbits a little more than 21,000 statute miles above the earth. Two of the fourteen earth terminals, with a total capacity of twenty-two voice channels, were installed in Vietnam: one at Ba Queo, near Saigon, and the other at Nha Trang. These satellite communications terminals went into operation in July 1967 with ten of the planned twenty-two voice channels accepted for use: five from Saigon to Hawaii and five from Nha Trang to Okinawa. By the end of 1967 the two Vietnam terminals were totally operational, and had been upgraded to their maximum capacity of eleven voice channels each.

In addition to the twenty-two military-owned and military-operated voice channels going into Vietnam, the Defense Communications Agency also leased from the commercial Communications Satellite Corporation ten other channels to complete the thirty-two channels required for Southeast Asia. These channels, which terminated at Bang Pla, just southeast of Bangkok, Thailand, were accepted for use in May 1967. Extension of six of these ten channels from Bang Pla to Vietnam was accomplished via the submarine cable link from Thailand to Vung Tau, where they interconnected with the wideband communications system in Vietnam.

On the last day of 1967 the original satellite communications system, called SYNCOM, which was near the end of its expected life cycle, went out of use in Southeast Asia. At that time the experimental satellite over the Pacific area lost its usefulness and the old SYNCOM earth station at BA Queo was closed. This forerunner of modern satellite communications had been pressed into service during a crisis when no one could be sure that it would work at all. It performed admirably, however, and for three years the experimental satellite communications system provided a vital link between the war zone and Washington, D.C.

The National Military Command and Control System

The years 1966 and 1967 saw a dramatic increase in the combat efforts in Vietnam by both U.S. and Free World Military Assist-


Photograph: Console Operator At Saigon Satellite Terminal

CONSOLE OPERATOR AT SAIGON SATELLITE TERMINAL. Soldier monitors satellite traffic and selects satellite to be used.

ance Forces, whose strength in Vietnam jumped from just over 200,000 in January 1966 to well over half a million by December 1967.

U.S. Army combat forces in Vietnam were bolstered by the arrival of the 9th Infantry Division at the turn of 1966-1967 and the 101st Airborne Division in December 1967, reuniting the 101st with its 1st Brigade, which had been in Vietnam since mid-1965. Another major Army combat force to appear was the 23d Infantry Division, Americal. This division, activated in Vietnam during September 1967, eventually controlled the 11th, 196th, and 198th Light Infantry Brigades. It was supported considerably during the organizational phases by the resources of the 1st Signal Brigade. This support was in the form of a rapidly organized signal unit, which was subsequently designated the Americal division's organic 523d Signal Battalion. At the same time, Army signal troops, which were to provide the communications for this combat force, went from 7,500 men to over 23,000 in the 24-month period.


But numbers alone do not tell the story. It is essential to understand the unprecedented concepts and working agreements that were developed to control and direct the communications effort, and to realize the extent to which the Defense Communications Agency, the Army's Strategic Communications Command organization, and the combat division and corps communicators had to merge their philosophies of operation and adjust their thinking to cope with the mission at hand. U.S. communications experience in the Vietnam War quite effectively redefined two words in the dictionary of communications-mobile and fixed. At one time these words brought to mind distinct and separate images that were the opposite of each other, but now in Vietnam fixed communications and mobile communications merged.

The Vietnam conflict saw the first large-scale combat employment of the centralized and worldwide National Military Command and Control System of the Department of Defense. The rapid and large buildup of U.S. forces in Vietnam demanded that this system be extended to and expanded within the Republic of Vietnam. Moreover, and perhaps paramount, the U.S. Government, because of internal U.S. sensitivity to the conduct of the Vietnam War, chose to exercise close civilian control over military actions. To do this, an unprecedented communications network was established in the field and between headquarters in Vietnam and higher headquarters outside the country, in this case, specifically, the Office of the President of the United States in the White House.

To attain the highest degree of command and control possible, a vast system of communications lines was built within Vietnam, stretching to Hawaii and eventually on to Washington, DC Every communications method was ultimately employed, from field wires and the infantryman's hand-held radio to submarine cables and orbiting satellites. No single service or organization can take all the credit for this extensive communications network; rather, it is to the credit of all communicators, military and civilian, that by the end of 1967 a system actually existed that allowed continuous, high quality communications from the fire base to the White House.

Training the Communicator

The proliferation of commercially procured, fixed-plant, and often automated systems and equipment, as operated by the Army's 1st Signal Brigade, required trained, experienced personnel. This requirement was not, of course, limited to the fixed-sta-


Photograph: Combat Signalmen With Task Force Oregon On Patrol


tion troops of the signal brigade. The communicators of the fighting forces and the signal brigade's area support units also encountered equipment and procedures that were foreign to combat communications of only a few years earlier. Such equipment as the new portable and mobile combat field radios and battlefield secure voice devices, together with such innovations as dynamic and effective airborne relay to extend the ranges of radio systems, and extensive heavy cable construction on combat bases all required installers, operators, and maintenance men, highly proficient in their trades. Training soldier-technicians, always an important task in Army communications, became more pressing and more complicated in the 1960s than ever before. This situation was an inevitable consequence of the ultrasophisticated and complex systems that were brought into the theater of war. Although the use of automatic equipment does, of course, reduce the number of operators, it requires of the fewer operators more training and greater skill.

When the first commercial quality backbone systems were installed in Southeast Asia, the Army had few Regular Signal Corps troops capable of operating and maintaining the system. Short-


term soldiers did not stay long enough to be trained on the job. The initial backbone terminals, therefore, and later the fixed-station additions, continued to be operated, even to the end of 1967, largely by civilian technicians of Page Communications and Philco-Ford. The presence of civilian communications controllers, maintenance technicians, and operators in a war zone, often in outlying and exposed locations, was something new in Army communications experience. It was another aspect of the unique war in Vietnam.

Ultimately, men in uniform had to be trained to do the work, however complicated and exacting and however difficult and costly the training. The cost became evident before the end of 1966. The two fixed-station prime contractors, Page and Philco-Ford, had contracted with the U.S. Government to establish complete wideband system terminals and schools at the U.S. Army Signal School, Fort Monmouth, New Jersey, to enable the Army to give soldiers adequate training. The cost to the government of these two contracts exceeded ten million dollars. The Page school was dedicated at Fort Monmouth in November 1967, and the Philco school opened a short time later. Not until well along in 1968, however, would soldiers trained in these schools arrive in Vietnam and Thailand.

Army signalmen working at the big communications terminals in the war theater were meanwhile learning their trade in an old and familiar Army manner-they were training on the job. An especially acute need for technical controllers on the wideband communications systems led the 1st Signal Brigade to establish a small school for this specialty in June 1966 under the auspices of the Regional Communications Group of the 1st Signal Brigade. Six months after the school opened, it had graduated 25 officers and 173 enlisted men to help stem the ever-growing shortage of technical controllers in the field.

The meager beginnings of the 1st Brigade signal school near Saigon, with its one course, was soon expanded both in the number of courses offered and in space and facilities. When the huge Army complex at Long Binh was ready for occupancy, the school, then known as the Southeast Asia Signal School, graduated from its one-room, country schoolhouse atmosphere and moved into the expanded Long Binh facilities. This signal training center at Long Binh was formally organized by the 1st Signal Brigade into the United States Army Training Facility, 1st Signal Brigade, in August 1968.

Although the school was a U.S. Army training facility, operated by the signal brigade, the scope of its instruction continually


broadened until it included courses for all communicators and electronics men from both United States and Free World forces, from the combat surveillance radar operator and combat radio repairman to the fixed microwave operator. By the end of 1968, for example, over 3,000 students had been graduated from the school, which had by then expanded its curriculum to more than twenty different courses of instruction on mobile and fixed equipment.

Summary, 1966-1967

As 1967 came to an end, the large communications systems in Vietnam were near completion. The over-all system, lean at best just two years before, was now taking shape, and the hand-to-mouth days seemed to be on the way out. The combat communicators­the troops of the corps, divisions, and separate brigades-had gained valuable experience during their service in the war zone, and the lessons were being well applied. The helicopters and the infantryman's radio sets, in both airborne and ground configurations, had been integrated so successfully that new meaning was given to the phrase "command and control." The combat multi­channel systems of the divisions and field forces were interconnected with and supplemented by the 1st Signal Brigade's Corps Area Communications System. Two of the three phases of the ambitious Integrated Wideband Communications System project were complete and in service. The combination of the fixed-plant, high quality communications links and the expanding dial telephone network lessened significantly the number of times the communicator had to hear that painful phrase "hoot 'n holler." Extensive working arrangements were in existence between the Saigon office of the Defense Communications Agency and the 1st Signal Brigade, and between the 1st Signal Brigade and the combat units. The control and direction concepts so painstakingly and, at times, painfully evolved in late 1965 and early 1966 were now bearing the fruits of success.

On the other hand, communications service was by no means perfect at the end of 1967. The long-distance general-user telephone system still relied on manual switching techniques. Message traffic in Vietnam still was sent via manual tape relays and, unfortunately, in some remote cases a personal visit was often faster than sending a message. Considerable refinements and improvements were now required in all areas of communications services. But the foundation had been built and now was the time to get about the business of major leaps forward in command control


Photograph: General Van Harlingen (seated) Inspects Communications Gear On A Command Helicopter


communications-electronics. The enemy had been continually met and defeated by our aggressive soldiers; relative security existed in all the cities and around the combat bases. It was generally believed that the Viet Cong and North Vietnamese would honor their self-declared truce during the coming February 1968 Tet holiday.


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