An Introduction to Ships of the Convoy War - the Battle of Atlantic in Steel Part 1 Corvettes...

The Battle of the Atlantic was the supply system that made Allied campaigns from Russia and Burma to Australia possible.

Detection and depth-charge attacks posed hard tactical choices because the escort's first duty was moving the convoy safely onward.

Aircraft could make submarine operations harder, but using scarce fleet carriers for the task created a serious strategic risk.

Early-war convoys were generally far smaller than later invasion convoys, and unreliable German torpedoes briefly eased the danger.

The Flower's modest size, 16-knot speed, and limited range made overseas bases and refuelling central to long-distance escort work.

Small escorts could be modified in service, while Flower construction showed the strategic value of ships that yards could produce quickly.

The class's modest submarine kill count matters less than the merchant ships and cargo its escorts got through.

The Castle class was only modestly larger than the Flower, but its reported higher speed addressed the risk of an escort falling behind its convoy.

A 1944 action illustrates why escorts continued to attack doubtful sonar contacts: driving submarines away was itself a convoy-protection result.