The provisions of this chapter relating to benefits and annuities shall not become operative until after the funds necessary to carry out this chapter have been provided. All claims for annuities or benefits arising before such funds are made available shall not be covered by this chapter; and the board is directed not to pay any annuities or benefits based upon any such claim; but, for the purpose of computing the length of service under this chapter, the board shall be authorized to include the period of time elapsing between February 1, 1950, and the date that it becomes operative.