Robin Chadwick

Thirty-Minute Theatre was an anthology drama series of short plays shown on BBC Television between 1965 and 1973, which was used in part at least as a training ground for new writers, on account of its short running length, and which therefore attracted many writers who later became well known. (Wikipedia)

Robert Hammond has died while "doing the deed" with his secretary and mistress Jennifer, and now his three sons have inherited the family trucking company, and each one will try to run the business in his own way. (imdb)