Tower Bridge as its northern landfall is in Tower Hamlets. The bridge consists of two bridge towers tied together at the upper level by two horizontal walkways, designed to withstand the horizontal tension forces exerted by the suspended sections of the bridge on the landward sides of the towers. The vertical components of the forces in the suspended sections and the vertical reactions of the two walkways are carried by the two robust towers. The bascule pivots and operating machinery are housed in the base of each tower. Before its restoration in the 2010s, the bridge's colour scheme dated from 1977, when
London Bridge Is Falling Down popular culture. There is considerable variation in the lyrics of the rhyme. The most frequently used first verse is: <poem>London Bridge is falling down, Falling down, falling down. London Bridge is falling down, My fair lady.</poem> In the version quoted by Iona and Peter Opie in 1951 the first verse is: <poem>London Bridge is broken down, Broken down, broken down. London Bridge is broken down, My fair lady.</poem> The rhyme is constructed of quatrains in trochaic tetrameter catalectic, (each line made up of four metrical feet of two syllables, with the stress falling on the first syllable in a pair;