PR' LINE MOUNTAIN SIGNAL FACILITY, a key site of the Integrated Wideband Communications System.
CHAPTER VII
Integrated Wideband Communications System
The Integrated Wideband Communications System was a microwave and tropospheric scatter communications web that eventually spanned the entire Republic of Vietnam and Thailand. The equipment was commercially procured, installed by a contractor, and the system was, therefore, of commercial fixed-station improved quality throughout. It constituted the Southeast Asia portion of the global Defense Communications System which had been delegated to the Army by the Department of Defense through its Defense Communications Agency. The completed system became by far the largest communications complex the Army had ever undertaken, creating an equivalent of the Bell Telephone System for South Vietnam and Thailand. However, the integrated system did not come into being quickly, easily, or, for that matter, inexpensively.
An urgent request for the fixed-plant system had been made in mid-1964, accompanied by a required implementation date of December 1965. The implementation date, however, was not met; in fact, fifteen months elapsed from the date of the contract award until the first link became operational in December 1966. This initial link was a small part of Phase I of the three ultimate phases of the Integrated Wideband Communications System.
In Vietnam, Phase I of the Integrated Wideband Communications System, incorporating and expanding the BACK PORCH links, was primarily intended to provide more circuits from Saigon and north throughout the country. A new extension was built from the Monkey Mountain site in Da Nang to Phu Bai, a large U.S. encampment area just south of the imperial city of Hue. In the center of a huge triangle between Saigon, Nha Trang, and Pleiku, an important circuit and system-switching facility was built on top of Pr' Line Mountain, a short distance to the southeast from Dalat. High-capacity links were to be provided between Pr' Line and the
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three corners of the triangle. Numbers of short links were built in and around the capital city area, where the fixed systems of Phase I replaced earlier tactical microwave circuits. Phase I of the integrated system was not intended to support a large troop buildup but was to provide the communications for up to 40,000 U.S. troops in Vietnam, primarily advisers and helicopter units.
As the force level in Vietnam grew, the requirements increased, and General Westmoreland's communicators were forced to ask for the Phase II upgrade. The Department of Defense approved Phase II in January 1966 and scheduled its completion for October 1966.
The primary purposes of Phase II were to expand both the major north-south backbone trunk system and the Saigon microwave complex, and to extend the fixed-plant system into new areas in support of combat operations. Sixteen new sites were to be added, involving twenty-five new communications links; nine Phase I links were to be upgraded to a higher capacity. In all, the total number of terminals was doubled, and the circuit total was tripled. When the Saigon-Nha Trang tropospheric scatter link was
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Concurrent with the award of a letter contract to Page Communications Engineers, Inc., for the Vietnam portion of the fixedplant system, the Army awarded the contract for the Thailand portion to Philco-Ford Corporation. In Thailand progress was made in the same phase pattern as in Vietnam. With the obvious exception of combat action, the problems experienced in Thailand during the ultimate completion of the wideband system paralleled those in Vietnam.
The installation project moved forward relentlessly, if somewhat unevenly at times, amid diversified problems and difficulties of funding, managing, supplying, and manning, which invariably accompany any large-scale effort. This effort, however, was unique in Army experience for its size and complexity. Implementation of such an ambitious project could not be expected to come easily. Construction and operation at the many sites, ultimately fifty-nine sites in Vietnam, fell short of the expected timetable. This situation was hardly surprising in view of such serious obstacles as remote sites and transportation difficulties in Southeast Asia and funding and programming delays in Washington. In retrospect, it is to the credit of everyone involved that the undertaking turned out as well as it did.
Because of these delays, Phase I and II were not completed on schedule. The last link of Phase I was not accepted by the government until January 1968, two years and one month after the original requested operational date of December 1965. Not until February 1968 did the last link of Phase II go into operation in Vietnam, a year and four months after the date requested, October 1966. The remainder of the Integrated Wideband Communications System, Phase III along with a few additional modifications,
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Such demands for the completion of the system, however, could not be easily met. The military had chosen to install a fixed, commercially procured system. And the commercial equipment needed for this system was entirely different from the communications hardware previously used in a war zone; it was custom built and enormously costly. In addition, engineering, manufacturing, testing, acceptance, and operation presented many difficulties at all levels. But it was the great expense of the system which surprised and chagrined many.
At Army and Department of Defense levels in Washington, the major impediment was getting money. The time-consuming process of funding had to come before anything else could be done. The budgetary mills of government could only grind out the funds slowly by increments. Yet, piecemeal funding, and the resultant bit-by-bit contracting and installing, apparently cost more in the long run than a single lump-sum allocation at the outset. For example, a Strategic Communications Command report dated 7 June 1967 states, in part: "This office has received a retransmission from Page Communications Engineers, stating that existing Phase III money would be exhausted by 15 July 1967 and that if additional incremental money was not forthcoming, the program will suffer in increased cost."
In mid-1966 the Assistant Secretary of Defense had returned a third addendum of the wideband communications program to the Defense Communications Agency for additional justification. The authorities in Washington were questioning the need for all the money that was being sought for channel expansions of trunks not yet in service and replacements of mobile combat systems at greatly increased capacity. They disbelieved the reports and requirements coming from the Southeast Asia war zone and insisted that the funds be minutely justified. The requirements had to be stated in detail, despite the fact that no one could determine the precise requirements far in advance. Frequently, changes had to be made in the system-in such matters as site location, equipment, and number of circuits-during the process of contracting and even of construction. Unforeseen demands continually arose requiring changes and, usually, expansion, even after installation had begun or had been completed. Not until May 1966 were the Phase I and II contracts with Page Communications Engineers, Inc., finally "definitized" for Vietnam. And four months earlier, Phase III
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The increases and changes occurring in the midst of the funding and approval process were not the result of inefficient planning. Rather, because of the graduated nature of the troop buildup and the constantly changing situation caused by combat activities, the volume and type of traffic and the disposition of subscribers were not known early enough or in sufficient detail to enable proper engineering of the trunking system. The logical steps in fixed-plant network engineering-traffic, plant, transmission, and equipment engineering-could not be followed in this case.
The difficulties encountered in obtaining adequate funds and establishing firm requirements were not the only factors contributing to the delays in the fixed communications project. From the very beginning of the program, problems of site concurrence and site access were almost endless. For isolated sites, the problem was especially time-consuming, beginning with the initial engineering surveys to find suitable locations. There were delays in getting aircraft and ground transport to remote areas in order to survey hilltop sites, and to make tests to determine the adequacy of proposed radio paths. Time was also consumed in obtaining permission from the local government to use these sites. Other delays ranged from the care required to avoid desecrating sacred trees in Thailand to the payment exacted for future harvests in Vietnam.
Site acquisition difficulties involving the terminals on bases already established were often only a matter of building space. In many cases, installation commanders who had agreed to furnish space were not able to do so when the time came for construction. These commanders discovered that their own unanticipated expansion had taken all of the available space. In addition, the space requirements for the system increased beyond original estimates. Buildings had to be erected, and in some cases expanded, to meet new requirements.
Production capacity and shortage of materials for the wideband system constituted another significant problem area. There were approximately 150 U.S. subcontractors providing material for the fixed communications in Vietnam and 100 subcontractors for Thailand. Page and Philco-Ford, the prime contractors, made every effort not to engage in direct competition for equipment by avoiding whenever possible the same vendors. In many cases, however, these prime contractors found themselves inadvertently competing
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The transportation of material, once it was finally available, was one of the most serious problems in the program. The accelerated buildup in Vietnam caused seaports and airports to become congested with cargo of every type imaginable destined for the war zone. Special-mission aircraft was the only means of getting the fixed communications hardware to Southeast Asia quickly. Throughout the period of installation, the U.S. Air Force Military Airlift Command provided special flights to bring the sorely needed electronic equipment into Vietnam. In addition, because a very active war was being waged and ground movement was constrained, the Air Force combat cargo aircraft and the Army cargo helicopters were often the only means of getting the hardware to the sites.
Site construction was accomplished in a variety of geographical and geological areas that include the rice paddies of the Mekong Delta, the mountainous, rocky mid-country region, and the sandy beaches along the coast. Each location presented a unique problem. Building and antenna foundations in the delta area had to be of a spread-footing design to prevent sinking in the water-soaked clay of the rice paddies. In sandy areas, the problem of soil erosion was so severe that it frequently appeared to defy solution. The very pronounced wet and dry seasons in Southeast Asia also controlled construction schedules. It was virtually impossible to accomplish any outside construction on communications sites during the rainy seasons.
Other problems affecting construction of the wideband system were the remoteness of some sites and the security restrictions at practically all sites. Army cargo helicopters were used extensively
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to transport men and material to mountain sites such as Pr' Line, Hon Cong Mountain near An Khe, and VC Hill at Vung Tau. Often considerable stretches of new road had to be built even before the actual work could begin. Use of the Vung Chua Mountain site, for example, just north of Qui Nhon, required the construction of thousands of feet of new road. In addition, an enormous amount of rock and dirt had to be removed from the site in order to provide a flat surface on which the facilities could be built.
In the latter months of 1966 additional delays and difficulties in construction and installation were caused by enemy action. Earlier, the big military communications sites had remained remarkably free from enemy harassment. It was almost as if the enemy favored the new communications services which Southeast Asia was receiving for the first time in its history.
On Thanksgiving Day 1966, however, a costly ambush of a communications equipment convoy occurred near Dalat in the hills of south central Vietnam. The convoy, manned by 1st Signal Brigade soldiers and contract civilian workers, was attacked while
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COMBAT SOLDIERS OF THE 1ST SIGNAL BRIGADE FIRING MORTARS FROM PR' LINE
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Another major attack affecting communications facilities occurred on the night of 26 February 1967 at DA Nang. The enemy launched a large surprise rocket attack against the DA Nang Air Base. One of the first enemy targets was the Army's signal compound on the base. Fortunately there were no casualties, but the rockets completely destroyed four vans in the communications complex which housed the temporary mobile message relay facility. Replacement vans were rushed to Vietnam by the Strategic Communications Command's 11th Signal Group in the United States, enabling reactivation of the tape relay in ten days. Actually, no circuits or links were completely out for more than a few hours, partly because of quick rerouting of circuits and partly because the enemy had failed to damage the big radio and technical control vans located adjacent to the tape relay facility.
At last, by the end of 1966, despite all delays and difficulties, the first circuits of the wideband system were tested, accepted by the Army, and "cut to traffic," that is, put into service passing actual communications. Brigadier General Robert D. Terry accepted the first link of the Integrated Wideband Communications System on 21 December 1966. This was one of two links which carried traffic between Phu Lam and the Tan Son Nhut Air Base in the Saigon area. These were the first fixed sites completed in Vietnam. The first links in Thailand had been put into use a little earlier, on 5 November, following the completion of tests between Korat and Udorn.
After the cutover of the first links, the wideband communications system flourished, fed by the multimillion dollar contracts to civilian companies and pushed by the thousands of combat signal troops that joined the 1st Signal Brigade in the 1966-1967 period. By mid-April 1967, hundreds of circuits in the integrated system had gone into service and eleven sites had been completed in Vietnam.
Combat Mobile Equipment Used in the Interim
It should be noted, however, that because of the long delays invariably encountered since the submission of the initial require-
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ments in August 1964, the fixed communications system could not keep pace with the huge buildup of U.S. and other Free World military forces in Vietnam. Keeping in mind that Phase I of the over-all system was designed to support 40,000 troops in Vietnam and that Phase II had a ceiling of 200,000, it can easily be understood that the Army communicators had many problems when the U.S. strength alone exceeded 350,000 men the day the wideband system's first circuit was put into service.
The solution to these problems, however temporary, was to use every piece of medium and heavy tropospheric scatter, microwave, and other mobile and transportable multichannel radio equipment that could be deployed into Vietnam. Throughout the long months of delay in the fixed communications project, the buildup of troops continued as did their appetite for long-haul circuitry. Consequently, the mobile tropospheric scatter and microwave links of the Defense Communications System were rushed into service and abounded throughout the country, not only providing circuitry from the backbone system to locations that would one day be served by the fixed communications being installed, but also sup-
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Regardless of the long, continued, and heavy dependence on mobile equipment for the long-haul Defense Communications System in Vietnam, enthusiasm among the customers ran high in 1967 as the fixed communications system became a reality. At mid-year in 1967, all praised the progress made by Phases I and II. Most of the basic links were in service or were being tested prior to activation. Wind-up activities of Phases I and II peaked in 1967, and by the end of November testing had begun on the final thirteen of seventy-six links. The last link of Phase I in Vietnam, between Vung Tau and Pleiku, was accepted on 27 January 1968, and acceptance of the last link of Phase II, between Vung Tau and Long Binh, followed one month later.
The total system upon completion of Phase II consisted of seventy-six communications links operating at fifty-eight sites in Southeast Asia. Of the more than ten thousand circuits, nearly all reached their destination by both tropospheric scatter and microwave radio trunks. However, a few circuits passed through a recently completed submarine cable system. This system, approved by the Department of Defense in February 1966, comprised six links, capable of sixty voice channels each, connected to the major communications sites at DA Nang, Qui Nhon, Nha Trang, Cam Ranh Bay, and Vung Tau in Vietnam, and Sattahip, south of Bangkok in Thailand. The installation was completed in May 1967. This dependable cable system, protected by its undersea route and interconnected with the fixed-station radio system at these six sites, constituted a valuable segment of the ever-growing Southeast Asia Wideband System.
Site construction meanwhile was progressing on the Phase III effort of the integrated system. Practically all of Phase III implementation occurred in 1968. While the first Phase III link in Vietnam, a 60-channel link between Vung Chua Mountain and Phu Cat Air Base, was accepted by the United States Government during December 1967, the entire system would not be completed until 1969.
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