  Using a complex representation of the Debney-Kerr-Schild (DKS) solutions and
the Kerr theorem we give a method to construct boosted Kerr geometries. In the
ultrarelativistic case this method yelds twisting solutions having, contrary to
the known pp-wave limiting solutions, a non-zero value of the total angular
momentum. The solutions show that twist plays a crucial role in removing
singularity and smoothing shock wave in the ultrarelativistic limit. Two
different physical situations are discussed.
