German wolf packs and how the allies responded?

In September 1939 with the beginning of World War II German U-boat operations got under way against allied forces the allies responded to the U-boat threat with a number of counter measures 
The combined affect of protection of ships by convoys harassment of U-boats by airplanes and other anti-submarine warfare measures reduced the ability of the U-boats to cut Britain off from her 
suppliers in North America In order to assess the effectiveness of the allied response it is first necessary to look at the U-boats In looking at the U-boats it is not only necessary to look at the 
various types of U-boats and their deployment but also to look at the Germans goals and the tactics that they employed in an attempt to reach those goals 
The Treaty of Versailles ending world war one prohibited Germany from having any U-boats When the treaty was changed under The Anglo-German Naval agreement one of the things that the 
Germans did to rebuild their navy was to rebuild the U-boat wing Their first U-boats were for general sea-going and coastal abilities the U-boats first built for this purpose were types I and II The type I had a surface speed of 1775 knots and 825 knots submerged on electric engines for armament it had 41 inch 
and 22 mm anti-aircraft guns and six torpedoes In comparison the type II had speeds of 13 knots surfaced and 7 knots submerged with three torpedoes and one 20 mm anti-aircraft gun The type II was 
smaller than the type I