Losing Vietnam (35 page)

When the communists called off their attack on Phnom Penh in mid-August 1973, the stocks of ammo, rice, and petroleum at the capital had been seriously drawn down, and it was necessary to rapidly build them up in preparation for dry-weather hostilities. In fact, the stocks were at an all-time low: we not only had to meet the current MEDTC and USAID daily requirements, but we had to increase the stockage to required levels, which demanded an understanding of the commodity situations.
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Cambodia was an agrarian society; more than 90 percent of its people were engaged in rice production. As the population fled the countryside they left their rice paddies untended; thus, the production of rice dropped dramatically.
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About half of the Cambodian government-controlled population became refugees. With rice production reduced by about 85 percent, from 3.81 million metric tons in 1969 to 0.56 million metric tons in 1974–1975, the free-market prices rose dramatically—increasing ten-fold between January 1973 and April 1975, far beyond the means of the huge refugee population. Malnutrition and starvation spread. To alleviate the situation, USAID attempted to maintain the Khmer's standard of living. Although that laudatory goal was not possible, since aid-financed imports could not offset reductions in production, the twenty-two AID personnel authorized in country did an outstanding job. The Cambodians became entirely dependent on the United States; without American rice they would certainly starve. Under the PL 480 assistance program, more than 470,000
metric tons of rice was delivered to Phnom Penh, 89 percent of all foodstuffs imported. Our job was to see that it was delivered to the depots. Distributing it to the people was another extremely difficult problem, which USAID handled. In October 1973, the daily PL 480 rice requirement was given as 550 metric tons, and this was certain to increase. In coordination with USAID, we set the Phnom Penh stockage objective at a ninety-day supply.

Petroleum products were essential to both the military and civilian components of the nation. The military required automotive gasoline, diesel fuel, aviation gasoline, and jet fuel. In the spring of 1974, the average daily consumption of petroleum was 690 cubic meters, of which 255 cubic meters were for the military. Use fluctuated greatly from day to day. The utility companies accounted for the major civilian uses of diesel oil and fuel oil, for water and electricity production; more than 63 percent of bulk petroleum was for civilian use.
¹⁷³

Funded by USAID, Telakhmer, the state-owned petroleum company, procured civilian supplies, although other petroleum companies (Shell, Esso, Caltex) distributed it. MEDTC requisitioned military petroleum from the DAO office in Saigon. Of the fuel for transit to Cambodia, about 75 percent was obtained at Nha Be, South Vietnam, and 25 percent at refineries in Singapore. Deliveries of petroleum were to Phnom Penh via the Mekong by small tanker vessels, to Battambang by road from Thailand, and to Kompong Som by tanker vessels.

The petroleum allocations, which varied between the wet season and dry season, averaged about 570 cubic meters per day. The storage capacity at Phnom Penh was thirty-five thousand cubic meters, so we established that as an objective. Military storage at Prek Phnom, ten miles north of Phnom Penh, was an additional seventy-five hundred cubic meters.

In December 1973, ammunition deliveries to Cambodia originated from depots in Thailand, where there generally were sufficient munitions on hand to meet requirements. MEDTC desired to maintain ammo stocks in country at a thirty-day required supply rate. The main ammo depot for both ground and air munitions was the Kantauk depot, located within the Phnom Penh perimeter. In varying amounts, stocks were also kept in some twenty enclaves throughout the country. The August 1973 enemy attack showed that the Kantauk depot could
be vulnerable in the future. Therefore, MEDTC set the limit of storage there at fifteen thousand short tons, so as not to incur a major loss by sabotage, interdiction, or being overrun.
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Table 22.
Storage Objectives and Replenishment Requirements (metric tons)

Source
: Maj. Gen. Ira A. Hunt, “Increased Use and Secutiry of the Mekong LOC,” November 1974, Headquarters USSAG, Nakhon Phanom, Thailand.

General cargo was more difficult to get a handle on. During the last half of FY 73 (January–June), a great amount of military supplies was shipped via the Mekong. This fulfilled the accelerated delivery of military assistance equipment—code name NIMBLE THRUST. Although most general cargo was military-funded matériel, there was also civilian cargo. For planning purposes, we estimated that general cargo would be approximately 250 metric tons per day.

The depot stocks and stockage objectives on 1 November 1973 are indicated in
table 22
.
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Not only would the monthly shipments on the Mekong have to increase greatly, from the previous eight months' average of 33,700 metric tons to 57,000 metric tons (a 69 percent increase), but depot stocks of ammo, rice, and petroleum would also have to increase by 68,256 metric tons, or 134 percent, in order to meet the stockage objectives. Therefore, the United States initiated an all-out effort entitled Project PILLAR POST to resupply Cambodia via the Mekong River.
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The immediate requirements were not only to increase the transportation of supplies and equipment via the Mekong, but to ensure the security
of transit. Having determined the transportation requirements, it was necessary to address the security aspects. Since 1973 there had been eighteen severe shipping losses on the Mekong. To prevent further losses we applied operations research to optimize the situation. We had to determine the convoy makeups and schedules, what they should be, what previous damages to convoys were, where and how often they occurred, what weapons were used, whether there were seasonal factors, and finally what could be done to improve convoy security.

First, we reviewed the convoy statistics for the previous eight months (March 1973 through October 1973), as the data was readily available.
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During the period there were 269,900 metric tons transported by thirty-four convoys totaling 230 vessels, an average of 6.8 vessels carrying 7,900 tons per convoy, with an average tonnage per vessel of 1,160 tons. The average monthly tonnage delivered was 33,700 metric tons, well below the replenishment requirements of 57,000 metric tons per month, to say nothing concerning the pressing need to rebuild stocks. If the current average number of convoys, four per month, were to continue, then the number of vessels per convoy would have to double—to fourteen. Consequently, the current contractual allocation of tugs and barges would have to be increased.

The addition of more tugs and barges to carry ammunition and rice would be no problem, since many were available from shipping contractors. However, there were only ten or eleven available petroleum tankers with the draft necessary to ply the Mekong, and their high profile made them vulnerable. (See
photo 5
.) At the time, only 40 percent of the petroleum stockage objectives at Phnom Penh were on hand. Consequently, petroleum resupply was critical. Therefore, it was important to determine the optimum Mekong convoy scheduling for petroleum by maximizing the tonnage transported for the given fleet while minimizing the essential troop commitments required to protect each convoy.
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We concluded that the optimum convoy cycles were an eight-day transit and an eight-day cycle, which we recommended that the tripartite deputies adopt.

About this time Major General Murray, DAO Saigon, received a letter from Lt. Gen. Nguyen Van Manh, RVNAF JGS chief of staff, which stated that too many small special convoys to transport rice and petroleum to Phnom Penh were being requested, causing a difficult
security situation for the RVNAF, which had to provide air, ground, and naval support to protect the convoys moving through South Vietnam. He cited two special convoys, one an oil tanker and a rice barge leaving Vung Tau on 17 October 1973 and the other an oil tanker and a rice barge leaving Vung Tau on 21 October. The USAID personnel in Phnom Penh obviously would have to plan to have their vessels join the tripartite scheduled convoys. Not only were these small unscheduled convoys grossly inefficient in transporting commodities, but they greatly disrupted military operations in South Vietnam's MR-4. The Cambodians had the same problem as the South Vietnamese, since air cover was essential, as was the insertion of ground troops at choke points. Each convoy, whether it was large or small, required the same security efforts.

Analysis of convoy security resulted in several major findings.
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Summary data from January 1972 until November 1973 indicated there was slightly more than one attack by fire per convoy and that all of these attacks resulted in eighteen instances of severe loss or damage. While this was a loss rate of only 1.6 percent, from a funding aspect these were ill-afforded losses. In the first nine months of 1973 the enemy sank four ammo barges, resulting in 2,534 metric tons of ammo being lost. The ammo losses amounted to $4.7 million—an amount MEDTC certainly could not afford. To understand the security situations, we had to determine where the attacks against the convoys were occurring, when and how they occurred, and whether there were any special factors in convoy makeup or discipline that affected matters.

An analysis
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of the 140 communist attacks against convoys traveling on the lower Mekong (that is, south of Phnom Penh to the South Vietnam border in 1972–1973) indicated that ninety-one were against northbound convoys and forty-nine against southbound convoys. Further, ninety-three were from the east banks and forty-seven from the west banks (see
photo 5
). All the attacks occurred in four key areas in the ninety-two kilometers from the South Vietnam border to Phnom Penh. The solution to suppressing enemy attacks by fire was, of course, to have the Cambodian military occupy the banks at these critical locations (see
figure 7
).

The Mekong River is more than four thousand kilometers long, and it drains an area of 795,000 square kilometers. It begins to rise
in May, following the onset of the southwest monsoon, and attains its maximum level in September or early October. At Phnom Penh, the river height is well over thirty feet in October, falling to a height of only seven to eight feet in April. During the dry season it is below its banks and the channels are narrow, giving the enemy a much easier time interdicting convoys. In 1972–1973 there were 1.6 attacks per convoy in the dry season and only 0.6 attacks in the wet season; in other words, a convoy was 2.6 times as likely to receive an attack in the dry season.
Figure 8
displays this information graphically for 1973. Since the convoys usually cleared Tan Chau in early morning, the transits, which
took anywhere from eight to twenty hours, were normally completed during daylight. The hours of attack, which depended on the convoy location, were generally in daytime. There were very few late afternoon attacks, and none were at night. Perhaps the key was to sail at night.

Photo 5. Convoy Passing through Mekong Narrows at Peam Reang Island with Petroleum Tanker on Fire. (Source: Headquarters USSAG, Nakhon Phanom, Thailand, produced by 432nd Reconnaissance Technical Squadron, U.S. Air Force.)