Attack on USNS Card

The Attack on USNS Card was a Viet Cong (VC) operation during the Vietnam War. It took place in the port of Saigon in the early hours of May 2, 1964, and mounted by commandos from the 65th Special Operations Group (Đội Biệt động 65).

Card was first commissioned into the United States Navy during World War II. Decommissioned in 1945, Card was reactivated in 1958 and entered service with the Military Sea Transport Service, transporting military equipment to South Vietnam as part of the United States military commitment to that country.

As a regular visitor to the port, Card became a target for local VC commando units. Shortly after midnight on May 2, 1964, two Viet Cong commandos climbed out of the sewer tunnel near the area where Card was anchored, and they attached two loads of explosives to the ship's hull. The attack was a success and Card sank 48 ft, and five civilian crew members were killed by the explosions. The ship was refloated 17 days later, and was towed to the Philippines for repairs.

Background
USNS Card was a that had served in the United States Navy. After 1945 Card was decommissioned and was transferred to the Atlantic Reserve Fleet. On May 16, 1958, Card re-entered service with the Military Sea Transport Service, under the control of the United States Navy. The ship was manned by a civilian crew and was prefixed "USNS" (United States Naval Ship) instead of "USS" (United States Ship) as it was in service but not commissioned.

With the escalation of the Vietnam War, the United States government stepped up military support for South Vietnam's fight against the Viet Cong. On December 15, 1961, USNS Card left Quonset Point, Rhode Island, with a cargo of H-21 Shawnee helicopters and U.S. soldiers from Fort Devens, Massachusetts, bound for Vietnam. At Subic Bay in the Philippines, the cargo and troops were transferred to USS Princeton (CV-37), which arrived and unloaded off the coast of Da Nang the following month.

From 1961 onwards, Card and USNS Core regularly docked in Saigon to unload heavy artillery, M113 armored personnel carriers, aircraft, helicopters and ammunition for the South Vietnamese government. The Port of Saigon was situated between the Te and Ben Nghe Canals, and was about 700 m wide from one side to the other. To facilitate the arrival of Card and other American ships which pulled into Saigon, the South Vietnamese military often deployed navy vessels to conduct patrols around the port, while the surrounding shores were protected by an elite Army of the Republic of Vietnam (ARVN) Airborne battalion. The port itself was guarded round the clock by Republic of Vietnam National Police, as undercover South Vietnamese agents operated across the river in the Thu Thiem area to disrupt VC activities there. Undeterred by the level of protection which the South Vietnamese government normally afforded to American ships, Tran Hai Phung—commander of the Viet Cong's Saigon-Gia Dinh Military District—ordered the 65th Special Operations Group to attack USNS Card.

Failed attempt on USNS Core
Despite their best efforts to control VC activities across the river in the Thu Thiem area, the South Vietnamese military and police could not stop VC agents from operating there. So VC members of the 65th Special Operations Group were able to watch U.S. and South Vietnamese military activities at the port, while they were preparing to attack American targets. Lam Son Nao, a commando of the 65th Special Operations Group, was also an employee at the port facility. As his unit was assigned with the mission to attack the carrier, Nao took advantage of his position as an employee at the port facility, to reconnoitre Card to design the best strategy to sabotage the ship and all the military hardware on board. Nao's father had previously worked at the port facility as a tradesman, so he memorised all the underground tunnels and sewerage systems which ran in and out of the facility. He advised Nao that the best way to enter the area where the American ships normally anchored, was through the sewer tunnel opposite Thu Thiem.

On one occasion while he was bathing in the Saigon River, Nao decided to inspect the sewer tunnel, which his father had advised him to use. Nao concluded that the tunnel would provide the best way to get in and out of the American area, but using it also presented challenges. The sewerage tunnel contained both waste and toxic oils which could cause blindness, so Nao and his men would have to close their eyes as they moved through the tunnel, in order to avoid blindness. Furthermore, Nao and his men must wash their bodies to get rid of the deadly odours to avoid detection, and probably arrest, by South Vietnamese authorities. After Nao had surveyed the tunnels which led into the port, he presented his plan of attack to the Saigon-Gia Dinh Military District Headquarters. Nao decided to utilise high explosives, enough to sink a ship, and to detonate them using a timer so that his men could get away safely. Nao's superiors approved the plan and they ordered him to launch the attack before sunrise to avoid killing local Vietnamese civilians.

Nao then returned to Saigon and began assembling the equipment required for the attack, which included C4 plastic explosives, TNT, wires, mine detonators and batteries. Nao also trained new commandos, namely Nguyen Phu Hung and Nguyen Van Cay, to support his operation. To ensure that his operation would go smoothly, Nao measured the height, length and width of the sewer tunnel to assemble the bomb devices to the right size, so it could be carried through the tunnel unhindered. Towards the end of 1963, Nao received news that Card had arrived in Saigon with another load of armored personnel carriers, artillery and aircraft. But the carrier turned out to be her sister ship, USNS Core. On the evening of December 29, 1963, Nao and Cay managed to carry their bomb devices through the sewer tunnel which had about 80 kg of explosives. The commandos attached the explosives to Core's hull, set the timer and retreated back into the sewer to wait for the outcome.

However, the bombs failed to explode as planned, because the battery had expired due to long periods of storage. Determined the operation would remain a secret, the commandos snuck back to Core and retrieved the explosive devices. Not long afterwards, Core and its crew sailed out of Saigon, intact without any damage. Nao, on the other hand, reported the failure of his mission to the Saigon-Gia Dinh Military District Headquarters; his superiors did not express disappointment in the failure of the operation, but instead they encouraged Nao and his men to destroy Card at all costs. Finally on May 1, 1964, Viet Cong reconnaissance teams spotted USNS Card as the ship sailed through Ganh Rai Bay and entered Long Tau River, so they immediately reported the information to the 65th Special Operations Group in Saigon. As usual, Card docked at the commercial port district in the city to unload another shipment of cargo and military helicopters, as well as load a cargo of helicopters scheduled to be returned to the United States.

Successful attack
When Nao received news Card had arrived in Saigon, he inspected the equipment which now included a new battery and a redesigned bomb. Again, Nao decided to set off the bombs during the early hours of May 2, so that he and his fellow operative could escape safely and avoid inflicting casualties on the local population. But due to illness, Cay declined to take part in the operation, so Hung had to replace him. At around 9am on May 1, Nao rushed to Hung's home, where the latter was given a hand grenade and was notified of an upcoming operation without much detail. At 6pm, after Nao had finished unloading the bombs onto one canoe, he and Hung traveled down the Saigon River in two separate canoes, towards the commercial port district. Both men then pulled over in the Thu Thiem area, to avoid detection from South Vietnamese authorities by intermingling with the local workers who lived there. While waiting for the right time, Nao briefed Hung on the objectives of the operation, which was to sink the largest American ship at the Saigon Port, and promptly report the results back to headquarters.

Shortly after 6:30pm as both men headed towards Warehouse Number 0 at the commercial port district, a police patrol boat spotted them and quickly gave chase. Nao then ordered Hung to throw the hand grenade and both men would retreat towards the local village, if their bombs were discovered by the police. The police patrol stopped about 20 m away from Nao's canoe, and the patrol boat commander questioned both men about their activities during that time of the evening. In response, Nao claimed that he and Hung intended to go to the other side of the river, to buy some new clothes at the market. To avoid delaying the operation, Nao bribed the patrol boat commander 1000 Vietnamese dong, as the South Vietnamese police were widely known for their corruption. When the patrol boat commander received the bribe, he gave both Nao and Hung permission to move on but demanded another bribe when they return. When the commandos arrived at the sewer tunnel, they assembled the bomb device with each man carrying 40 kg of explosives down through the tunnel.

Once the commandos finally got out of the tunnel, they both swam towards the broadside of Card which anchored near the opening of the sewer. As planned, Nao and Hung attached two bombs on the ship, with one near the bilge and one at the engine compartment, just above the water surface. After the bombs had been attached to Card's hull, Nao inspected both bombs to ensure they had been assembled properly. After that Nao stuck the battery onto a pole and connected it to the bombs with wires, then set the timer. At 1.10am, the bombs were completed and both commandos retreated back into the sewer tunnel, and climbed into their canoes on the other side and rowed back to Thu Thiem. Again, the police patrol boat was waiting for Nao and Hung to arrive, because the commander wanted another bribe. As Nao and Hung approached the patrol boat, an explosion was heard and a bright light could be seen in the commercial port area. The South Vietnamese police patrol boat then started its engine and raced towards Card, instead of extracting another bribe.

Aftermath
For the VC commandos of the 65th Special Operations Group, the explosion on Card signalled a successful mission. By the time the sun rose over Saigon, Card had settled 48 ft into the river with its engine compartment completely flooded. Furthermore, five American civilians who worked on the ship died as a result of the attack. Due to the rapid response from the ship's crew and the local authorities, flooding inside the ship was quickly stopped and it was stabilized. An inspection later revealed that the explosion had torn open a hole which measured 12 ft long and 3 ft high, on the starboard side of the ship. In the days that followed, five U.S. Navy divers were deployed to Saigon from the Philippines, in addition to several salvage teams from U.S. bases in Japan and the Military Sea Transport Service Command. Amongst the divers was founding US Navy Seals member Roy Boehm, who claimed to have recovered the remains of a Hagerson Demolition Pack, a specialised explosive charge used by US navy frogmen. Bohem speculated that the explosives used in the attack had actually been stolen from his own South Vietnamese Navy unit by a group of deserters who had been mistreated by a South Vietnamese officer.

USS Reclaimer (ARS-42), a rescue and salvage ship, which was heading for the Philippines at the time, was ordered to change course and sailed for Saigon. Meanwhile, the tugboat USS Tawakoni based at Subic Bay in the Philippines was placed on standby, and later received similar orders to head for South Vietnam. Upon their arrival in Saigon, U.S. Navy divers and salvage teams tried to pump water out from Card's flooded compartments, but their initial attempts were hindered by a combination of malfunctions in the pumping equipment, and the poor diving conditions in the river. Ultimately it took the salvors 17 days to refloat Card, and when that was completed they began the process of moving the ship out of Saigon by installing a 6-inch pump and a load of generators inside Card to get rid of excess water while at sea. Reclaimer and Tawakoni then towed the damaged Card out of Saigon, and headed for Subic Bay where it underwent further repairs.

Shortly after Card was sunk, North Vietnam made full use of the incident for propaganda purposes. On October 20, 1964, the North Vietnamese government issued a postage stamp which proclaimed an "Aircraft Carrier of America sunk in the Harbor of Saigon", to praise the Viet Cong commandos who carried out the attack. The U.S. Navy refused to admit Card had been sunk even for a brief period of time, instead it simply stated Card was damaged and quickly repaired. For the remainder of 1964, the VC launched further attacks on U.S. targets such as the Brinks Hotel and Bien Hoa Air Base, but there were no significant responses from the U.S. military. Card was returned to service by December 11, 1964 and remained in service until 1970, when she was placed into the Reserve Fleet.