Blue Bridge, Heritage bridge in Kronstadt, Russia

Blue Bridge is a road bridge in Kronstadt, Russia, spanning the Obvodny Canal and featuring blue painted metal railings with granite supports on each side. It carries both vehicle and foot traffic and connects different parts of the city along Makarovskaya Street.

Construction began in 1791 under the merchant F. Bekrenev of Petrozavodsk and was finished by June 1794; the wooden drawbridge with a chain mechanism was first painted green, then blue. In 1874 it was rebuilt to a design by Lieutenant Colonel Petrovsky as a turning iron bridge with a wooden deck, its metalwork by the Archimedes plant and gas lamps supplied by the Kronstadt gas works, completed by summer 1875. A 1964 overhaul widened the roadway and sidewalks.

The bridge's name comes from its blue paint, applied after the original green. Nearby, on the Obvodny Canal embankment, a monument to the blockaded stickleback was unveiled on 8 May 2005 for the 60th anniversary of victory in the Great Patriotic War; the fish helped Leningraders survive the siege.

The bridge is open at all times and can be reached on foot from the surrounding streets in the city center. Walking along the canal banks nearby gives a good view of the railings and the granite supports.

The Kronstadt tide gauge is fixed to the abutment of the Blue Bridge: in 1840 hydrographer M. F. Reineke marked the mean level of the Gulf of Finland from 1825–1839 observations, and this line became the zero of the gauge from which depths and heights are measured in Russia. The 1874 rebuild dismantled the bridge piers down to water level and destroyed Reineke's original notch.