 Seeing this , the frigate captain Robin , friend of Louis Faidherbe , asked Prince Jérôme Napoléon , Minister of Algeria and the African Colonies , for approval for construction of a floating bridge . Opened on July 2 , 1865 , the bridge had a total length of 680 metres ( 2 @,@ 230 ft ) ( the floating part of the bridge had a length of 350 metres or 1 @,@ 150 feet ) and a width of 4 metres ( 13 ft ) . The floating part was formed from 40 metal pontoons which supported a wooden deck . Three of these pontoons were specially designed so that it could be created a 20 metres ( 66 ft ) gap so that large vessels could pass . The bridge was named Faidherbe Bridge by a decree of Napoleon III of France . 
