HMS Erne (U03) from the left
Here we see the Black Swan class sloop HMS Erne (U3), the next step up from the corvette, and also used as a convoy escort ship. The three main turrets seen in this picture each carried two 4in anti-aircraft guns, as the sloops were not expected to encounter enemy surface vessels.
How to cite this article:
Rickard, J (9 March 2019), HMS Erne (U03) from the left , http://www.historyofwar.org/Pictures/pictures_hms_erne_u03_left.html