Two cargo tank vehicle designs are no longer authorized to transport hazardous materials requiring a specification package, the Federal Motor Carrier Safety Administration said last month. The rear-end protection devices on MC-331 cargo tank motor vehicles assembled with designs T-5314, certified on March 10, 1997, and T-5602-A, certified Sept. 12, 1997, by Chemical Transportation Engineering Consultants Inc. of Lubbock, Texas, do not meet minimum design requirements.