The members of the retirement board shall be the trustees of the several funds provided for by this chapter, and shall have exclusive control and management of such funds, and shall have full power to invest the same, subject to the terms, conditions, limitations, and restrictions imposed by law upon savings banks in the making and disposing of investments by savings banks; and, subject to like terms, conditions, limitations, and restrictions, such trustees shall have full power to hold, purchase, sell, assign, transfer, or dispose of any of the securities and investments in which any of the funds provided for by this chapter shall have been invested as well as of the proceeds of such investments, and of any moneys belonging to such funds.