Bob was born in 1909 in what was then countryside between Falkirk and Carron in Stirlingshire. His father was from Tophichen, an Iron Grinder, his mother from Stirling. But the family soon moved to Camelon and it was there that firstly he lost his father in 1918, Bob was nine, and the following year his mother remarried, her new husband a widower with slightly older children, the two families simply combining at his mother's address. 

Johnston would as a younger teenager play his football locally, clearly becoming a noteworthy centre-half but without junior honours. Indeed after Strathallan Hawthorn and Bothkennar United he made only a few appearances for junior Alva United before being scooped up. However, he would have to wait two years for a first-team appearance and throughout his Roker time would have stiff competition for his place. Yet he was clearly held in high regard. He was retained throughout as a player, then as a trainer, becoming senior trainer in 1951 and effectively assistant manager under his previously long-time playing colleague, Bill Murray. And meantime he coached the Norwegian national team in the late 1940s and even England B in matches against Scotland in the 1950s.

However, by the end of 1956-7 Sunderland was struggling. It had dropped from ninth in the First Division to third from bottom, Bill Murray was sacked, replaced by Alan Brown, who cleared out Murray's staff including Bert. It didn't help the club. It was relegated the following season and would not return for half a dozen more, by when he had managed a couple of local teams and run an off-license in the city until his early death at fifty-nine in 1968, to be buried in BIshopwearmouth Cemetery.