Joseph Armstrong and his younger brother George were locomotive engineers and staunch Methodists. Joseph, was born at Bewcastle, Cumberland on 21 September 1816. The family went to Canada in 1817, returning in 1824 to Newburn-on-Tyne. Joseph encountered both George Stephenson and Timothy Hackworth during his apprenticeship at Walbottle Colliery and worked for several railway companies before joining the GWR in 1854. He served as locomotive superintendent at its Wolverhampton works until transferred to Swindon as locomotive and carriage superintendent in 1864. During the period when the GWR was moving from broad- to standard-gauge rolling-stock he designed and adapted many locomotives and carriages. He introduced a number of improvements to the working conditions of his staff, served as President of the Swindon Mechanics' Institute and on the council of the Institute of Civil Engineers. He was a WM local preacher. He died of over-work on 5 June 1877. Two sons, John Armstrong (1851-1931) and Joseph Armstrong junior (1856-1888), and one grandson also became railway engineers.
George Armstrong (1822-1901), his younger brother, was born in Canada on 5 April 1822 and on leaving school worked in Walbottle colliery before following his brother to work as a railway engineer. In 1864 he succeeded his brother as locomotive superintendent at Wolverhampton, holding the post until he retired in 1897. He became a member of the Instiutution of Mechanical Engineers in 1866. Like his brother, he was a member of the WM church. He died in Wolverhampton on 11 July 1901.