American Bridge, Saint Petersburg

About

The American Bridge (also referred to as The Howe Bridges, or Nikolaev Railway Bridge until 31 December 2008) is essentially a group of railway bridges that connect the Bezymyannyi island (St. Petersburg) to the left bank of the Neva River via the Obvodny Canal, and provide links between the Central and Nevsky districts of the city of Saint Petersburg.

The wooden bridges of the same design as now were constructed over the period 1840-1850 during the construction of the Nikolayevskaya Railway. The main construction works were supervised by the prominent American railroad engineer George W. Whistler to a design by William Howe, an American bridge builder and inventor.

The essence of this construction project was that the bridge spans were a truss system (which was very new) consisting of timber support systems delimited by steel crossbars. The presence of metal components made the bridge structure much stronger without significantly increasing the overall weight. The William Howe's system was theoretically checked and then improved by the Russian engineer Dmitrii Juravsky, who was an executive assistant to George W. Whistler during the construction of the railway line. Juravsky performed structural analyses and tests on physical models of Howe trusses from 1843 to 1848, and executed studies of the effect of posttension in Howe trusses. He published two books "About Bridges of the Howe System" in 1855 and 1856. Juravsky was able to prove that the closer to a bridge's pillars, the greater the strain on the vertical tension bars and diagonal braces. So, he proposed to make the truss members of varying thickness depending on a specific location. His ideas were endorsed by Whistler, and then used in the construction of other rail bridges on this line. As the road was built in the forward direction, it was necessary to build 278 artificial structures.

The wooden bridge over the Obvodny Canal was originally constructed by George W. Whistler using the Howe-Zhuravsky system. It served its purpose effectively for approximately three decades. However, in 1869, a decision was made to replace it with new metal spans. The task of designing the new bridge was entrusted to Nikolai Belelubsky, a renowned Russian civil engineer who had successfully constructed numerous railroad bridges throughout the Russian Empire. Belelubsky showcased his exceptional talent and expertise as both a scientist and a practitioner. He managed to organize and categorize existing steel bridge designs, subsequently developing a set of standardized span structures. Although modifications were made to the design of the wooden bridge, the resulting metal structure bore a striking resemblance to the previous truss system known as the Howe-Zhuravsky. Just like its wooden predecessor, the newly constructed steel bridge also featured a double-track configuration. The Major yard in Saint-Petersburg saw significant advancements, leading to a steady growth in its operations. The terminal witnessed a rapid increase in both passenger and cargo traffic, which was attributed to the expansion of the rolling stock. However, a shortage of space on the left bank of the Obvodny Canal necessitated the construction of a new train maintenance depot on the right bank. Additionally, new crossings were also built to accommodate the rising demands of the station. In 1906, a single-track American bridge, designated as bridge number 2, was constructed adjacent to the pre-existing metal bridge, which eventually became known as bridge number 1. Subsequently, in 1911, an additional rail bridge with two tracks and identified as bridge "B" was incorporated into the existing structures. In 1913, a double-track bridge featuring the letter E was constructed. Subsequently, in 1916, another bridge was added to complete the structure, this time adorned with the letter A. The design of these bridges closely resembled the railway bridge located in Tsarskoye Selo, spanning the Obvodny Canal on the railroad track near the Vitebsky railway station.

Adapted from Wikipedia (CC BY-SA). Photography via Wikimedia Commons.