Section 2--614. Substituted Performance

(1)  Where without fault of either party the agreed berthing, loading,
  or unloading facilities fail  or  an  agreed  type  of  carrier  becomes
  unavailable   or   the  agreed  manner  of  delivery  otherwise  becomes
  commercially impracticable but a commercially reasonable  substitute  is
  available, such substitute performance must be tendered and accepted.
    (2) If the agreed means or manner of payment fails because of domestic
  or  foreign  governmental  regulation,  the  seller may withhold or stop
  delivery unless the buyer provides a means or manner of payment which is
  commercially a substantial equivalent.  If  delivery  has  already  been
  taken,  payment by the means or in the manner provided by the regulation
  discharges   the   buyer's   obligation   unless   the   regulation   is
  discriminatory, oppressive or predatory.