This part establishes procedures for assigning priority for use by defense agencies, on commercial terms, of commercial shipping services, containers and chassis, and port facilities and services and for allocating vessels employed in commercial shipping services, containers and chassis, and port facilities and services for exclusive use by defense agencies (as defined in 340.2), at any time where appropriate under provision of title I of the Defense Production Act of 1950 (50 U.S.C. App. 2061 et seq.) as determined by the Secretary of Transportation. The procedures will provide the means to require vessel and port operators to provide defense agencies with existing commercial services and facilities not obtainable through established transportation procurement procedures. Thus the procedures will minimize interference with commercial operations and ensure rapid response to defense needs in times of crisis or war.