After the Second World War, the development of prestressed concrete enabled innovative bridge
structures and construction methods. Numerous prestressing systems were introduced during this period,
exhibiting considerable variation in mechanical properties, structural design, and construction
techniques. Since their launch, these systems have frequently developed, but retained their original
names. Consequently, modifications resulting from accumulated experience, documented damage, or
updated guidelines remain unconsidered and are typically disregarded when evaluating existing
structures. This paper examines two of the earliest prestressing systems employed in Germany, which
differ fundamentally in structural design and prestressing concept. Through two case studies from the
1950s, the paper illustrates how specific damage mechanisms, particularly grouting deficiencies, may
have originated and developed over time. The investigation analyses the development of relevant
guidelines and prestressing systems through examination of historical approval documents. The study
summarises how system modifications may have contributed to mitigating grouting-related deterioration
in later structures. Significant differences are revealed between the original characteristics and
requirements of the prestressing systems and their subsequent iterations due to detected damage.
Consequently, classifying prestressing systems into different generations appears appropriate, as this
could contribute to a more differentiated assessment of the condition of existing structures in the future.