Mott, Hay and Anderson
Mott, Hay and Anderson (MHA) was a UK-based consulting civil engineering firm founded in 1902 by Basil Mott and David Hay. David Anderson joined in 1920, and the company became Mott, Hay and Anderson. They specialized in heavy civil engineering projects such as bridges, tunnels, railways and docks and remained active until 1989, when they merged with Sir M MacDonald & Partners to form Mott MacDonald.
Early on, the partners used their experience from building London tube routes on projects like reconstructing and extending the City & South London Railway, enlarging the Central London Railway, and creating lifts under St Mary Woolnoth church at Bank Underground station. They also did underpinning work on Clifford’s Tower and widened Blackfriars Bridge, with Anderson serving as resident engineer on that bridge project. The firm also advised on underground railways in Sydney, Africa and Russia.
In the 1920s and 1930s, MHA designed notable bridges and railway works, including the Queensferry crossing over the River Dee, the Wearmouth Bridge in Sunderland, and the Trent Bridge in Nottingham. They enlarged the City & South London Railway tunnels and extended them to form part of the Northern line of the London Underground. They advised on a new Mersey crossing in Liverpool, which led to the Queensway tunnel opened in 1934. They also introduced early bolted concrete tunnel linings for the London Passenger Transport Board and designed a road tunnel at Dartford.
During the 1930s, G L Groves joined as a partner, but the firm kept its name. Two founding partners died in 1938, and wartime work during World War II included designing deep-level London shelters, armaments factories, repairing bomb damage to bridges, tunnels and docks, and converting unfinished Central line tunnels into aircraft factory space.
After the war, MHA designed the Tyne Tunnel and continued designing many major road tunnels, including Dartford’s second tunnel, Mersey Kingsway, Blackwall’s southbound tunnel, the Hatfield and Penmaenbach tunnels, and others. They also contributed to the design of the Forth Road Bridge and the Severn Bridge with Freeman Fox & Partners. Other projects included the Tamar Bridge in Cornwall and the Kuala Lepar Bridge in Malaysia, and work on London Bridge.
In the 1960s, work on the Victoria Line divided tunneling duties between MHA and Halcrow. John Bartlett, a partner, patented a bentonite-slurry shield tunnel boring machine, helping pave the way for the modern earth pressure balance TBMs. An alliance with Australian firm John Connell Group led to the Melbourne Underground Rail Loop project, opened in 1981, and eventually to a joint venture in Hong Kong for the Chek Lap Kok airport area and the Lantau Link.
As time passed, many of the founders’ projects aged, and the firm updated its ventilation and tunnel systems. In the 1980s, the Blackwall northbound tunnel was refurbished under MHA’s supervision. The company also explored opportunities like the Medellín Metro in 1979 and worked on Channel Tunnel plans for decades.
MHA played a major role in Channel Tunnel discussions and designs. They first explored a Britain–France tunnel in 1930 and later advised on an early, now-familiar service-tunnel concept. In the 1970s, they helped British Rail and SNCF with aerodynamics studies for high-speed trains in long tunnels. They were advisers to the Channel Tunnel Companies and worked on exploratory contracts when political support fluctuated. In the early 1980s, MHA contributed design services for the British side of the Channel Tunnel and, between 1986 and 1994, spent about 650 man-years on Channel Tunnel design work.
In 1989, Mott, Hay and Anderson merged with Sir M MacDonald & Partners to form Mott MacDonald, a firm that grew beyond traditional consulting engineering and took on broader roles, including education services for Islington in London.
This page was last edited on 2 February 2026, at 22:44 (CET).