Spontaneous and organized forms of disguised labor struggle must be distinguished from such individual acts of resistance. They required maximum cover, absolute reliability, technical ingenuity, and an orientation beyond the immediate situation. Sabotage was aimed not at husbanding physical energies but at harming the adversary, whether for reasons of personal revenge or for military or political motives. Consequently, it was largely limited to the core groups of the political and national resistance. Along with the communist opposition, many Russian, French, and Polish prisoners played a prominent role. Organized and spontaneous sabotage frequently meshed. The direct destruction of machines or the turning out of defective, unusable pieces were possible only at considerable risk. Sabotage demanded subtle methods in order to disguise the origin of the fault. In the camp, the first point for sabotage was where materials were distributed and data processed. In Dachau, the card catalog of prisoners’ qualifications was manipulated by the labor-statistics office so that skilled specialists were not transferred to armaments plants—instead, the companies were given workers they first had to train. On the other hand, politically reliable skilled laborers were channeled into key positions in order to organize sabotage directly on the spot. At the Gustloff factory in Buchenwald, prisoners succeeded in systematically reducing the production of carbine barrels over a period of months, while at the same time wearing out enormous numbers of special tools. In Natzweiler, during the disassembly of damaged airplane engines, prisoners also damaged the parts that were still intact. At the Heinkel Works, young Russian prisoners from Sachsenhausen regularly removed valves that were extremely difficult to replace. In rocket assembly at Dora-Mittelbau, prisoners diverted materials being transported, disposed of small parts on the sly, rendered tools unusable, and welded seams in violation of all technical specifications. The success of such acts of sabotage rose in direct proportion to the extent the SS itself was involved in monitoring production. It had too few officers to pinpoint the causes for the fault. On the other hand, turning out defective pieces demanded a high level of technical knowledge on the part of the prisoners, lest these faults be discovered during production or final monitoring, and the workplace responsible be identified.