This image from the book "Vietnam Studies: Field Artillery 1954-1973" by Major General David Ewing Ott shows the organization of NVA and PLAF sappers. The chart is accompanied by the following text:

"No description of the North Vietnamese Army and the People's Liberation Armed Force and their effect on allied forces would be complete without mention of the ubiquitous sapper. During the first half of 1969, sapper attacks inflicted an average of over $1 million damage per raid. However, the role of the sapper was often misunderstood. Before 1967, the enemy had not grasped the significance of the sapper as an assault soldier. The allies, on the other hand, sometimes erroneously categorized the sapper as a guerrilla simply because some guerrillas employed sapper tactics. The fusion blurred identification. The development of the sapper and his employment before and after the creation of a separate sapper combat arm, equivalent to the infantry and artillery, must be traced before his impact on the war can be appreciated.

The term sapper originated in Europe and traditionally identified a combat engineer. In Vietnam this conventional association remained, but a more particular connotation increasingly qualified the sapper. The sapper signified a raider-ranger unit and gained notoriety as the lead element in an assault on a fixed installation or military field position. Armed primarily with explosives charges, the sapper breached the defensive perimeter and neutralized tactical and strategic positions and thus prepared for the attack of the main body.

Before 1967, however, the sappers were often misused. As late as 1964, the People's Liberation Armed Force envisioned the use of sappers only during the first phase of guerrilla warfare, before the government of Vietnam could establish strongpoints and improve defensive positions. Sapper units remained subordinate to the infantry and served as reinforcements in assaults. Deep penetrations were disallowed. Sapper units were constrained in their operations until the artillery had fired. And sappers themselves were occasionally deficient when employed in raids. Inadequate preparation, incomplete reconnaissance, and inexperience of the demolition men used as penetrators all contributed to the poor execution of these missions. Nevertheless, the number of sapper units in South Vietnam increased steadily after 1965, and by 1967 the enemy recognized the misemployment but also the potential of these forces. The North Vietnamese Army upgraded the entire organization and, in late April or early May 1967, created the Sapper Headquarters, Sapper Department, Joint General Staff.

The sapper force, as an independent combat arm equivalent to the infantry or the artillery, operated (1) in the assault without infantry, (2) in the assault with infantry, (3) in special action group activities, and (4) in "water sapper" operations. Sappers in special action groups operated essentially in the cities, proselyting the population and maintaining pressure, while water sappers mined ships, bridges, and other water-associated targets. Special action groups and water sappers were of less immediate importance to the artillery in Vietnam than were sappers employed in the first two modes.

Sapper assaults, with or without the infantry. depended on stealth and secrecy. Their primary method of attack called for making deep thrusts into allied positions from different directions and hitting several targets simultaneously. Organization was determined by the specific mission and the location and strength of the allied forces. Characteristically, however, the sapper force included assault, security, fire support, and reserve elements. (Chart 1)

Assaults without the infantry required fullest use of the fire support or reserve elements. either separately or in combination. The sappers disguised their attacks as attacks by fire through the use of mortars by the fire support elements or as infantry assaults through employment of the reserve elements, which were the equivalent of infantry squads. If the deception worked, the opposing forces would deploy to their bunkers or to the defensive perimeter and leave the center of the installation vulnerable to assault teams.

Sapper attacks with the infantry were either with the sappers in support of the infantry or the infantry in support of the sappers. Sapper units considered supporting the infantry a misuse of their tactical abilities. Attached to a large unit, they tended to lose the advantages of secrecy and surprise. Nevertheless, sappers continued to be employed as reinforcements to the infantry. The second mode of sapper operation-using the infantry as a reserve, security, or secondary assault element-seemed more effective. The greatest threat to al lied positions was an attack spearheaded by sappers with explosive charges, followed by the infantry some 100 to 200 meters behind.

During 1968, after the sapper organization had been made a separate combat arm, attacks by sappers or by un its employing sapper tactics occurred on a larger scale and often were accompanied by indirect fire support. By the end of that year, heavy Communist losses resulting from. large-scale offensives made the sapper and his techniques empirical necessities. Minimum manpower expenditure was imperative, yet military pressure had to be maintained. The sapper was well suited to these dual demands. A captured enemy document explained that considerable damage could be inflicted by a relatively slight force through the cautious application of sapper tactics: small numbers of men could "inflict extensive damage on enemy installations." The sapper should concentrate on strategic structures "located deep within enemy controlled areas" rather than concern himself with inflicting casualties. The ability to penetrate, and not the preponderance of firepower or men, was crucial. But, the document warned, sapper attacks should "not normally last over 30 minutes after the enemy is aware of the sapper presence."

From the beginning of 1968 until mid-1969, sappers were essential to the enemy's effort. Although they participated in only 4 percent of all assaults, these made up 12 percent of all significant assaults- those which inflicted serious damage. From January 1968 until May 1969, the frequency of sapper raids remained at about five per l11onth, but their effectiveness greatly improved. The average raid during 1968 resulted in approximately $300,000 damage. In 1969, the average raid inflicted more than $1,000,000 damage and accounted for more allied casualties. The selection of targets testified to the increasing boldness of the sapper units. In 1965 the use of sappers against allied combat positions such as outposts, fire support bases, and landing zones was still debated, but in 1967 training for this type of attack was rapidly progressing. During 1968 and 1969 these field positions made up 43 percent of the sapper targets; fixed military installations such as storage depots, base camps, and Air Force installations accounted for 32 percent of the sapper raids; and population centers accounted for 18 percent of the total. More than 51 percent of the raids occurred between 0100 and 0300. General Giap showed the increasing confidence in sapper units when he exclaimed, "Regardless of how strongly the US or puppet troops are defended, they can be easily destroyed by our crack and special troops with their special combat tactic."

The creation of the Sapper Headquarters in 1967, the need for troop conservation, especially after 1968, and the demonstrated effectiveness of the sapper during 1969 contributed to the growing emphasis placed upon these forces. The expansion of the sapper combat arm mirrored this emphasis. In July of 1967 the V-25 Infantry Battalion, a PLAF regional unit in Quang Nam Province, was scheduled to be upgraded to main force status and retained as a sapper force , Here was the first clear indication that large infantry units were being converted into sapper units. By June of 1968, nine main force and regional force battalions and sixteen companies of sappers were in existence. In early 1969, the sapper force had grown to nineteen battalions and thirty-six companies, And by mid-1969, this force had increased to twenty-seven battalions and thirty-nine companies.

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