Obituary: Constance Tipper

"Her vigour in prosecuting her work in an extremely male preserve will always be remembered and admired by those who came into contact with her . . ." Thus the late Lord Baker about Constance Tipper, the distinguished yet unpretentious woman who made an important contribution to Britain's survival in the Second World War. She was the first to discern the reasons why Liberty ships tended to break in two.

It was in 1943 that Tipper began her important work on the cause of brittle fracture in Liberty ships, after the appointment of J.F. Baker (later Lord Baker) as Professor of Engineering at Cambridge. The Liberty ships were the merchant ships, constructed with great haste at the beginning of the war, which brought vital supplies across the Atlantic to Britain. A number of these ships, complete with their cargoes, had been lost in heavy seas, breaking up like glass, a crack running instantaneously right round the ship. Tipper revealed that the fault in the ships lay not in the method of fabrication and use of welding, as had been suspected, but in the material used, which became dangerously brittle under certain conditions. Her name is now known to engineers of all ages as the creator of the "Tipper Test" for determining brittleness in steel.

Constance Elam, the daughter of a surgeon, started her education at St Felix, Southwold, and went to Newnham College, Cambridge, in 1912. She graduated in 1915 with a Third in Part I of the Natural Sciences Tripos, but this did not prevent her from achieving a DSc in London in 1926, and a ScD in Cambridge in 1949.

In 1915 she went to the Metallurgical Department of the National Physical Laboratory in Teddington, but quickly moved in 1916 to the Royal School of Mines in Kensington, west London. She was appointed Research Assistant to Sir Harold Carpenter at the Royal School of Mines in 1917, and awarded two successive Fellowships - the Frecheville (1921-23), and the Armourers' and Braziers' (1924-29). Having evolved a method of preparing metal crystals she worked at this time with G.I. Taylor of Cambridge, accumulating data on the deformation of these crystals under strain. The Royal School of Mines arranged with Lord Rutherford at the Cavendish Laboratory that whilst continuing to be employed by the school she should work in Cambridge. In 1928 she married George Tipper, a graduate of Clare College, Cambridge, and the Superintendent of the Geological Survey in India. When she left the Royal School in 1929 she settled in Cambridge and continued her work there for over 30 years.

Her old college, Newnham, made her a Research Fellow for the year 1930- 31. The university, in the Cambridge fashion of those days, gave her testing facilities in the Engineering Department and in 1933 a room in that department, but she had no official status even though the Leverhulme Trust awarded her a Research Fellowship for two years in 1936. She felt her position keenly, but she was still prepared in 1939, on the withdrawal of several lecturers to wartime jobs, to undertake a considerable amount of teaching for the department. She also took charge of the Heat Treatment laboratory where important work was carried out in connection with war contracts.

Newnham elected her an Associate Fellow for three years; and in 1949 Cambridge University made her a Reader. From this time until her retirement in 1960 she was a full member of the Faculty of Engineering and the only woman at the time to hold office in that traditionally male department. She took a full share in teaching both undergraduates and graduates, and continued her research work in what little time was left after her teaching commitments had been met.

Her published work includes a book for the Oxford University Press, Deformation of Metal Crystals (1935), and The Brittle Fracture Story (1962), with the Cambridge University Press.

After officially retiring in 1960 Constance Tipper continued until well into her seventies with consultancy work at the Barrow shipyards, and in overseeing progress and improvements in metal bridge construction and other metal structures. She bought Bank House, Langwathby, in Cumbria, in 1955, principally to enjoy the family hobby of fly-fishing. She also enjoyed gardening, water- colour painting and playing the piano.

Constance Tipper celebrated her 100th birthday in 1994, and to mark the occasion Newnham College planted a variegated sweet chestnut in the gardens, now known as the Tipper Tree.

Phyllis Hetzel

Constance Fligg Elam, metallurgist: born New Barnet, Hertfordshire 6 February 1894; Reader in Mechanical Engineering, Cambridge University 1949-60; married 1928 George Tipper (died 1947); died Penrith, Cumbria 14 December 1995.