Thomas Blackadder established his own engineering firm, The Blackadder Brothers' Garrison Founder and Engine Works in 1851. His son, Thomas Blackadder Jr. was born 4th October 1865. He worked in his father's foundry and was awarded a Master Mason certificate in 1924. He served in the navy for a number of years. He was married to Violet Isabella Blackadder (b. 1895, d. 1984), daughter of James and Violet Scott. Thomas Blackadder Jr. died in 1941. They had two children. His son is Thomas Scott Blackadder (b.1926), who was the CEO of Diamond Power Speciality Ltd between 1963-1994. His daughter is Dame Elizabeth Blackadder (b. 1931, d. 2021), a famous Scottish painter.