Turnbull played rugby as a boy for St. Peters RFC, one of the smaller teams based in Cardiff, along with his brothers, Maurice and Kevin. Maurice would later play for Cardiff and like his brother would also represent Wales, though he is better known for representing England at cricket.
Bernard Turnbull was first selected to play for Wales against Ireland in the 1925 Five Nations Championship under the captaincy of Idris Jones. Wales were humiliated in the match, losing 19-3, in the biggest victory Ireland had achieved against Wales. Turnbull scored the only points for Wales with a try, his only international points. Turnbull missed the 1926 Championship, but was re-selected for the 1927 tournament and in the opening match against England was given the captaincy. In a tight game played at Twickenham, Wales lost narrowly 11-9, and even scored more tries than their opponents; a good feat considering they played three quarters of the match with 14 men after Dai Jones was injured in the first half. Turnbull played in the next game of the championship against Scotland, but for the third time found himself on a losing Welsh team.
Turnbull's next game was against England in the 1928 Five Nations Championship, in a game Wales should have won but for a slip by the normally reliable Rowe Harding. Turnbull was now on a match losing streak for Wales but his next game was against France, who had failed to beat Wales in the first 13 Championship encounters. Like the 1927 match against England, France was a 14-man team for the majority of the game after an early injury; therefore when Wales lost the game the result was an even bigger embarrassment. Turnbull was not selected for the 1929 Welsh season but was back in 1930 for his final game against Scotland at Murrayfield. Wales lost 12-9 and Turnbull ended his international career without experiencing a Welsh victory.
In 1931, Turnbull faced the touring South African team as part of the Cardiff team. Turnbull turned out with his brother Maurice and fellow Welsh internationals Ronnie Boon, Archie Skym and captain Harry Bowcott. Although Cardiff lost, sports journalist 'Old Stager' said: "B. R. Turnbull was the best centre on the field, ubiquitous in defence and valiant in attack."[3]
Wales[4]
