The board shall set up and maintain a benefit trust fund account in which shall be placed all payroll deductions, payments, and income from all sources. All property, money, funds, investments, and rights which shall belong to or be available for expenditure or use by the plan shall be dedicated to and held in trust for the members and for the purposes herein set out and no other. The board shall have power, in the name and on behalf of the plan, to purchase, acquire, hold, invest, lend, lease, sell, assign, transfer, and dispose of all property, rights, and securities, and enter into written contracts as may be necessary and proper to carry out its duties.