Born in Bolton, Openshaw was a keen cricketer, and once took all ten wickets in a Bolton Cricket League match. He moved to Crewe to find work, and became an engineer in the railway workshops there. He joined the Amalgamated Engineering Union and in 1930 was one of the youngest members to be elected to the union's executive council.
Openshaw represented the AEU on the National Executive Committee of the Labour Party from 1940 to 1948, and at the Trades Union Congress (TUC). He served as the TUC's representative to the American Federation of Labour in 1947, and was also elected to the General Council of the TUC in 1948.
In 1953, Openshaw was elected as the President of the AEU; he served until his retirement, three years later.
|Trade union offices|
Tom O'Brien and Sam Watson
| Trades Union Congress representative to the American Federation of Labour
With: Arthur Deakin
Herbert Bullock and William Harold Hutchinson
| President of the Amalgamated Engineering Union
1953 – 1956