Barrett's natural gifts were reinforced by a robust constitution and formidable capacity for hard work. ... Each night [during his time as a pastor], the hours from 10pm to 2am were set aside for research. The lectureship at Durham in 1945, and chair in 1958, allowed him to settle into a more reasonable 14-hour day, which he carried into retirement.Do read the whole thing. (HT: Mark Goodacre)
Here is another obituary in the Telegraph, whose author obviously missed Barrett's sense of humour.
My own reflections on Barrett are here.