Requirements are prioritized to determine which requirements will be included and excluded from the project. Rationale/Purpose Defining requirements specifies the capabilities, features or attributes of the projectâs deliverables.
On January 31, 1917, Germany, determined to win its war of attrition against the Allies, announced it would resume unrestricted warfare in war-zone waters. Three days later, the United States broke diplomatic relations with Germany, and just hours after that the American ship Housatonic was sunk by a German U-boat.
If under attack by surface ships, there was some chance for some of the crew to escape and be rescued by the attackers: three of four u-boats sunk off the US coast with survivors were sunk by surface ships, compared to only one u-boat sunk by aircraft attack with survivors. U-166 - sunk 30 July 1942 in the Gulf of Mexico. No survivors, 52 dead.