This depends on which London Bridge is meant.
There were various wooden and stone bridges that preceded the current London Bridge. The original London Bridge, which featured an intricate complex of houses, shops and a chapel, 19 small arches and a drawbridge with a gatehouse at each end, took 33 years to construct (1176-1209). This was replaced by a new bridge which took six years to build (1825-1831). Construction of the most recent London Bridge was begun in 1967 before the previous bridge was removed (and which now resides in Arizona), so took around five years to build, being completed in 1972.
1886 to 1894
Eight years
About six years.
1886 to 1894
The current bridge was built between 1968 and 1973.
Tower Bridge is in London.
how long does it take to build a beam bridge of 2400 sq ft
Ten
The present bridge was built between 1968 and 1973.
it took 3 months to build the iron bridge in Newport Pagnell
It took approximately 6 years to build the London Eye.
About 4 years.