 In eight days in commission, "U-28"s tally was over 13,000 tons, already exceeding the totals of all four U-boats of the .The following month, "U-28" sank the 3,881-ton collier "Maston" from Cape Spartivento, Calabria, on 13 August, killing two men of the British ship's crew.Three days after "Maston" went down, "U-28" sank "Bradford City", a 3,683-ton British Q ship in the Straits of Messina, with no loss of life.