1882-1887 - apprenticed in the engineering works of Sir William G. Armstrong at Elswick-on-Tyne.

1887 - went to London to work in an independent practice as electrical contractor and consulting engineer, installing electrical lighting in many country houses; developed considerable skill in photography as a child, which remained a lifelong hobby.

Swinton produced the first photograph produced by X-rays in England, published in Nature (23 January 1896), within a month of the announcement of Röntgen's discovery. In association with Sir Charles Parsons, Swinton was also involved with the early development of the steam turbine, and with the construction of the turbine ship Turbinia, a torpedo-boat destroyer built in the mid 1890s.

1908 - Swinton proposed the use of cathode ray tubes for both the transmission of television pictures and their reception or display, but did not patent the idea; opposed the adoption of Baird's mechanical system by the BBC in the 1920s.