Mott, Hay and Anderson was founded as a private partnership between Basil Mott and David Hay in 1902, with the original firm name of Mott & Hay. Prior to forming the original partnership, Mott and Hay had spent time building London tube railways and Hay had worked on the Blackwall Tunnel. Both engineers had worked together since 1888 on the City and South London Railway under Sir Benjamin Baker and James Henry Greathead. Early projects included the reconstruction and extension of the City & South London Railway, the building and extension of the Central London Railway, the construction of lifts beneath St Mary Woolnoth church at Bank Underground station, the underpinning of Clifford's Tower, the reconstruction of Southwark Bridge and the widening of Blackfriars Bridge. Mott and Hay employed a young engineer called David Anderson as resident engineer for the latter project.