Ind. Code § 8-4-7-13

Sec. 13. It shall be competent for the board of directors of such union railway company to organize a board of managers, to consist of a representative from each proprietary company, as well as a representative from each associate company previously admitted, such representatives to be selected by the respective companies which they are to represent, and the president of the union railway company shall be ex officio president of such board. As associate companies are from time to time admitted to the use of the union railway property and facilities, as aforesaid, they shall each become entitled to have a representative on said board of managers; but after such board of managers shall have been organized, other associate companies shall only be admitted as aforesaid with the unanimous consent of all the members of such board of managers.