London Bridge is a pre-stressed concrete box girder bridge.
John Mowlem & Co.
1973. The previous bridge was re-erected in Lake Havasu City, Arizona.
It was constructed by John Mowlem & Co.
Tower Bridge was constructed as an opening bridge to allow boats with tall masts to get into the Pool of London. It became available for use in 1894.
Nobody discovered it - it was built as a means of getting from one side of the River Thames to the other. It wasn't always there, it had to be constructed.
The current London Bridge was designed by Mott, Hay and Anderson. The bridge was constructed by contractors John Mowlem & Co from 1967 to 1972, and opened by HM Queen Elizabeth II on 17 March 1973. It is the tenth known bridge in this spot, the first having been built by the Romans.
By workmen using steel, iron, stones, mortar, cranes etc.
Because the original bridge was the ONLY bridge in London at that time.
Tower Bridge and London Bridge.
Gemini bridge
Tower Bridge is east of London Bridge.
London Bridge. The Olympic rings are on Tower Bridge - not London Bridge.