Hartung columns

Sun, 24 Oct 2021 01:22:32 +0200

This is a relict of a former S-Bahn bridge and an open exhibition about the Hartungsche Säulen . The bridge over the Stadthausstraße was built in 1903 and was replaced by a new one in 2005/2006. The memorial in the Stadthausstraße was placed nearby the original location of the old bridge. A small sign explains the use and the history of the columns.

During the Wilhelminian period (late 19th to early 20th century), Berlin underwent rapid urbanization and technological modernization. The expansion of public transport, including double-decker buses and electric trams, required that bridges for trains had to be lifted higher so that doppeldeckerbusses and electric trams could pass underneath safely. For this, a new intermediate support beam was needed. A design competition was held, which the engineer Hugo Hartung won with his ‘Model II’. Hugo Hartung (1868–1919) was a German civil engineer known for his work on bridge construction and steel structures. His Model II column, or “Hartungsche Säule,” became a standard feature in Berlin’s railway infrastructure. Since then, they were used for railway bridge supports in Berlin because of their technical advantages, their attractive design, their low price, and their lower tendency to corrode compared to structural steel. The columns were typically made of cast iron, which, due to its high carbon content, is more resistant to corrosion than many early steel alloys. Their fluted design was not only decorative but also provided additional strength and stability. They were connected to the capitals (headpieces) and the base via ball joints to compensate for vibrations in the bridge. This ball-and-socket joint system allowed the columns to absorb and dissipate dynamic loads and vibrations from passing trains, reducing stress on the bridge structure and prolonging its lifespan. However, around 1902 they were seen as no longer up to date because of their unfavorable behavior when exposed to heat. Cast iron, while strong in compression, can become brittle and expand unevenly when subjected to high temperatures, which posed a risk in the event of fire or extreme heat. Nevertheless, the Hartung columns were used unchanged until 1914 in the construction of numerous railway bridges in Berlin.

Karlshorst on Grainy Mære

Hartung columns