313.11  Bids — specialized construction.
  The department may contract for specialized construction work for beam straightening, beam replacement, and beam repair on bridges, without advertising for bids as required under section 313.10, if all of the following conditions are met:
  1.  The work is of a specialized type in which fewer than five contractors engage.
  2.  The department solicits written bids from all available contractors engaged in the specialized type of work.
  3.  The work can be done for less than forty thousand dollars.
90 Acts, ch 1137, §1