Adding even a few escorts to the normal force materially changed a convoy's defensive options. Groups grew from four or five ships to six or seven, with reserve groups of another four or five vessels available when needed. An attack involving roughly 30 U-boats is the example given for a concentration that could justify calling in such a surge force. That depth made it possible to reinforce a convoy confronted by a major threat instead of leaving it to fight alone with its routine escort. Escort numbers therefore created operational flexibility as well as a larger local screen.
Notable Point · 23:30-24:18
Reserve escorts and the ability to surge
Growing escort strength gave convoys a reserve: extra groups could be sent to reinforce a route facing a concentrated U-boat attack.