A retirement system may be established for city employes by ordinance in any city of the second class A which system, when established, shall be administered by a city retirement board, which shall consist of the president of the city council, or his representative, who shall be its chairman, the city treasurer, or his representative, and one city employe to be selected, from time to time, by the city employes for a term of two years. Each member of the board shall take an oath of office that he will diligently and honestly administer the affairs of the board, and that he will not knowingly violate or permit to be violated any of the provisions of this act. Such oath shall be subscribed by the member taking it and shall be filed among the records of the board. The members of the board shall not receive any compensation for their services, but shall be reimbursed for all expenses necessarily incurred in the performance of their duty.

Two members of the board shall constitute a quorum.

The retirement system, herein provided for, shall be established immediately upon final enactment of the ordinance providing for the same.