Prachechny Bridge (Saint Petersburg)

 interesting place, road bridge, UNESCO World Heritage Site, listed building / architectural heritage, 1760s construction

The Prachechny Bridge is located along the axis of the Palace Embankment at the source of the Fontanka River, connecting the 1st Admiralty Island with the Nameless Island and the Palace Embankment with the Kutuzov Embankment.

The bridge is three—span, stone, arched, its length is 40.9 meters, the length along the rear faces of the abutments is 39.2 meters, the width is 20.6 meters, the width along the cornice is 15.7 meters. The superstructure is a hinged arch, it is a solid curved stone vault lined with granite. The middle arch is wider and higher than the symmetrical side arches. The abutments and supports are stone on a pile foundation, lined with granite. Oval lucarns (holes) have been created above the intermediate supports to facilitate masonry, which facilitate the masonry of the bridge.

The railing is a solid granite parapet. Granite slabs are laid on the sidewalks. The roadway is separated from the sidewalk by a granite curb. The sidewalks of the postcards on four sides have ten steps to go to the level of the embankments.

Prachechny Bridge is one of the first stone bridges in St. Petersburg. This is not just a bridge, but an architectural creation of its time. Its creation took place at a time when the Baroque gave way to classicism. Embankments were dressed with stone and faced with granite, and bridges in the center of St. Petersburg were rebuilt in stone.

The original project, drawn up in 1762, provided for the construction of a three-span stone bridge with a wooden drawbridge. However, in the final draft of the embankment, the bridge became non-separable.

The bridge was built in the period 1766-1769 by the architect I.L. Rossi and the "square maker" T.I. Nasonov, simultaneously with the construction of granite embankments near the Summer Garden. The bridge got its name due to its proximity to the palace laundries located on the corner of Sergievskaya Street (now Tchaikovsky Street).

The bridge is three-span, stone, arched. The superstructures according to the system are a hinged arch, and according to the design — a solid stone arch outlined along a box curve, lined with granite. The middle arch is wider and higher than the symmetrical side arches. Abutments and supports are made of stone, granite facing on a pile base.

In 1908, during the survey of the bridge, significant deformations were found due to the subsidence of the supports. The results of the survey by divers of the pile foundation showed that its deformations led to the subsidence of the middle span, the opening of seams in the parapets (because of which they lost their previous forms), the formation of cracks in the left river support, etc.

However, major repairs of the bridge were carried out only in 1926 according to the project of engineer B.D. Vasiliev. The crossing was fenced with lintels from the Neva and Fontanka River and the water was pumped out. The pile base of the river supports was reinforced with a concrete cushion. The ice cutters were shifted anew, additionally strengthening the underwater parts with wooden sheathing and bars. Cement mortar was injected under pressure into the joints of the masonry.

After the repair, the architectural appearance and design of the bridge have not changed much, only the "humpback" slope of the roadway has been somewhat softened.

Prachechny Bridge is located in the heart of the historical center of St. Petersburg, near the Summer Garden. Its original architectural appearance has been preserved to the present day. The bridge belongs to the list of objects of cultural heritage of Russia of federal significance.

en.mostotrest-spb.ru/bridges/prachechnyj