The moneys in the fund shall be kept separate and apart from any other fund by the treasurer of the municipality, and the moneys in the special fund may be invested by the corporate authorities of the municipality in securities legal for the investment of the sinking fund moneys of the municipality. The interest earnings on investments shall be paid into the special fund. The corporate authorities may sell any such securities and reinvest the moneys in other securities or convert such securities into cash when the same may be needed for expenditure under the provisions of this act.
53 P.S. § 1433