Blue Bridge (Saint Petersburg)

 road bridge, UNESCO World Heritage Site, 1840s construction

The Blue Bridge over the Moika River is the widest bridge in St. Petersburg. It connects the Kazan and 2nd Admiralty Islands.

This is a single–span structure with a length of 29.4 meters, the width of the bridge along the cornices is 95.4 meters, the width of the bridge along the postcards is 113.85 meters. The total area of the bridge is 2,294 square meters, the area of sidewalks is 143 square meters.

The superstructure of the Blue Bridge is a hinged arch made of cast iron and reinforced concrete. The railings are cast iron, artistic casting, the pattern repeats the pattern of the Moika River fence. The sidewalks are separated from the roadway by cast-iron railings of a simple pattern. The bridge is part of the ensemble of St. Isaac's Square.

Since 1737, there has been a wooden drawbridge here, which got its name from the color of its coloring. Later it was rebuilt into a three-span with a wooden superstructure on stone supports like the Kryukov Canal Bridge.

In 1818, according to the project of V.I. Geste, the bridge was rebuilt into a single-span cast-iron arch. The superstructure was a double–hinged arch, by design - a solid vault.

The construction fell to the lot of the follower of V.I. Geste – the bridge builder P.P. Bazin. The superstructure is mounted from cast-iron sections connected by bolts. Cast-iron structures were manufactured at the Olonets Iron Foundry. The abutments of the Blue Bridge are massive stone, on a pile foundation, lined with granite. Cast-iron grilles are installed on the bridge.

The sidewalk was separated from the roadway by cast-iron railings of a simple pattern with cast-iron bollards. There were several ornaments on the facades of the superstructure. The pavement on the bridge is stone paving. Originally it was narrower, its width was 41 meters.

In 1842-1843, in connection with the construction of the Mariinsky Palace and the redevelopment of St. Isaac's Square, it was expanded upstream towards the Red Bridge to 97.3 meters. The superstructure was constructed of cast-iron tubing connected by bolts. Since 1925, cracks have appeared in the cast-iron boxes of the vault from the lower side, built in 1818.

In 1929-1930, the cast-iron arches on the lower side were replaced with reinforced concrete ones, and the old bridge abutments were preserved. The superstructure is a double-hinged arch. The cast-iron part, built in 1842, has been preserved to the present day.

In 1938, the stone paving on the bridge was replaced with asphalt concrete.

The bridge was repeatedly reconstructed in the XIX-XX centuries, its dimensions and design features changed. Despite this, its appearance has not changed, and the appearance of the ferry has reached us almost in its original form. To the bridge, as well as to the Mariinsky Palace located next to it, the saying applies that two emperors turned away from it: the position of the equestrian statues (the Bronze Horseman and the monument to Nicholas I) is directed away from the bridge.

The Blue Bridge, simple in its architectural design, is organically integrated into the ensemble of granite embankments of the Moika River. Next to it are the Mariinsky Palace, St. Isaac's Square with a monument to Nicholas I, St. Isaac's Cathedral, the buildings of the All–Russian Institute of Plant Growing named after N. I. Vavilov and his library, nearby is the Composer's House. You can also see the Admiralty building from the bridge.

Initially, according to the project of Geste, granite obelisks were used as lamps. Lanterns copying the lamps on the Alexander III Bridge in Paris were installed at the end of the XIX century. These lamps have been preserved on the bridge in their original form for a long time. The existing floor lamps were restored during the reconstruction of 2013-2014. on the model of the floor lamps of the Baltic railway station.

In 1971, a granite footstool decorated with the trident of Neptune was installed on the Moika embankment near the lower part of the Blue Bridge, designed by architect V. A. Petrov. The column marks the water level of the largest St. Petersburg floods: 1824, 1903, 1924, 1955, 1967. Petersburgers nicknamed it the "Neptune scale".

Major repairs of the bridge were carried out from April 2013 to September 2014. The reinforced concrete arch was reinforced with additional reinforcement, the construction of a reinforced concrete unloading arch over the cast-iron part was carried out, the restoration of the railing and cast-iron metal decking was carried out. Also, the power fence and floor lamps were recreated, the supports were repaired, the granite lining of the walls of the interface of the supports with the embankment, the cast-iron tubing was repaired. The river bottom is reinforced with concrete mats. Islands of safety appeared on the bridge.

Due to its record width, the Blue Bridge has become a kind of "invisible bridge" - many perceive it not as a crossing over the Moika River, but as part of the square. The Blue Bridge fits seamlessly into the surrounding architectural ensemble with all its historical buildings and monuments. Many guides conducting tours of St. Isaac's and Senate Square notice that the bridge and the nearby Mariinsky Palace "fell out of favor" with two Russian emperors at once: equestrian statues of Nicholas I and Peter I (the Bronze Horseman) they stand with their backs to the bridge and the palace.

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