Mott, Hay and Anderson (MHA) was a successful 20th century firm of consulting civil engineers based in the United Kingdom. The company traded until 1989, when it merged with Sir M MacDonald & Partners to form Mott MacDonald. History Early years The company was founded as a private partnership between Basil Mott and David Hay on 30 July 1902. Prior to forming the partnership both had spent time building London tube railways and Hay had worked on the Blackwall Tunnel, so it was no surprise that they concentrated on heavy civil engineering projects such as bridges, tunnels, railways and docks. 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. The firm also advised on proposals for underground railways in Sydney, Africa and Russia. David Anderson was made a partner in 1920 after returning from army service. The firm was thereafter known as Mott, Hay and Anderson (MHA). During the 1920s, MHA designed the rolling bridge over the river Dee at Queensferry, the Wearmouth Bridge in Sunderland and the Trent Bridge in Nottingham. They also designed the enlargement of the City & South London Railway tunnels and their extension past Camden Town and Clapham South to form the Northern line of London Underground. In 1920, Basil Mott joined forces with Sir Maurice Fitzmaurice and John Brodie to advise on the best way to build a new crossing of the river Mersey in Liverpool. In 1922 a tunnel was recommended. Mott, Hay and Anderson subsequently designed the works and supervised the construction of the tunnel. The tunnel, named Queensway was opened in July 1934. In the 1930s, the firm designed the first bolted concrete tunnel linings, for the London Passenger Transport Board. The new tunnel linings were used on the Ilford extension of the Central line between Redbridge and Newbury Park. MHA designed a road tunnel at Dartford and supervised the construction of its pilot tunnel beneath the Thames, but preparations for construction of the full-size tunnel were stopped in 1931 due to economic difficulties. G L Groves became a partner in