Orr was born in Scotland, and worked in the coal industry there before serving in the 14th Highland Light Infantry in World War I.

As part of his role with the Mineworker's Council of Action, he was also the national organiser for Australia's Militant Minority Movement, and he was elected as General Secretary of the Australian Coal and Shale Employees' Federation in 1933 as a result of his involvement with these groups.

On one occasion his suggestion that striking miners should be armed (to protect themselves from strike-breakers and police) resulted in a charge of incitement to murder.

[1] Orr was a competent organiser, orator and arbitrator, and during the 1930s was able to gain a number of major concessions for miners as a result of strike action and negotiation.

Actions and discussions which he organised were responsible for the introduction of a 40-hour working week for miners below ground, the appointment of a Health and Safety Commission for Mines, and a Royal Commission which resulted in the Coal and Oil Shale Mine Workers' (Pensions) Act of 1941, improving miners' retirement options.