This class was built primarily for A/S training and to replace the 'H' class which by this time were considered very much past their best. Originally not intended for war but forced into the role by hostilities and the fact that they could be produced very quickly.
In theory they were in all aspects inferior to almost all foreign submarines, their performance and success during WWII proved otherwise.
The need for these boats to be used operationally decreased after hostilities ceased in the Mediterranean and stopped altogether at the end of WWII. Consequently they were used in the role for which they were originally intended, Anti-Submarine Training boats.
191 oa - Ursula 197 oa after modification.
1 x 3 inch/45 QF MkI.
6 x 21 inch bow tubes, 4 reloads.
6 x 21 inch bow tubes, 2 reloads or later 6 MkII mines.
3,800/120 nmiles at 10 kts sf/2 kts sm.
27 in Peacetime (4 Officers and 23 Others).
31 in Wartime (4 Officers and 27 Others).