Brian,
Here are some notes extracted from the Admiralty War Diaries for 1 & 2 August 1940. Sorry could not find anything on 16 Aug 1940.
Admiralty War Diaries 1/8/40
Casualties and Defects - City of Brisbane and City of Dundee
Aground 1 mile NE of L.1 buoy. Request tugs to be sent immediately (Wolsey 1142/1 to C. in C. Nore). Have tried and failed to tow off City of Dundee. Am proceeding (Wolsey 1308/1 to C. in C. Nore).
Admiralty War Diaries 2/8/40
Enemy Air Activity - City of Brisbane
(Ashore South Long Sand) Bombed 16.57 during salvage operations damaged by 2 bombs (C. in C. Nore 1807/2) Unlikely vessel can be floated (C. in C. Nore 1921/2) Salvage operations had to be abandoned 1915/2 owing to persistent bombing attacks - vessel now badly damaged, all compartments on fire aft near magazine. Some loss of life among crew. (C. in C. Nore 1426/2)
Casualties and Defects - City of Brisbane
Aground in 51 33 N, 1 20 E, (South Long Sand)
If available request fighter protection when enemy raids approach. (C. in C. Nore 0433/2 to A.C.C., in C., F.C.)