49 CFR 179.3 - Procedure for securing approval.
(a) Application for approval of designs, materials and construction, conversion or alteration of tank car tanks under these specifications, complete with detailed prints, must be submitted in prescribed form to the Executive Director - Tank Car Safety, AAR, for consideration by its Tank Car Committee and other appropriate committees. Approval or rejections of applications based on appropriate committee action will be issued by the executive director.
(b) When, in the opinion of the Committee, such tanks or equipment are in compliance with the requirements of this subchapter, the application will be approved.
(c) When such tanks or equipment are not in compliance with the requirements of this subchapter, the Committee may recommend service trials to determine the merits of a change in specifications. Such service trials may be conducted only if the builder or shipper applies for and obtains a special permit.