  Cylinders in projective varieties play an important role in connection with
unipotent group actions on certain affine algebraic varieties. The previous
work due to Dubouloz and Kishimoto deals with the condition for a del Pezzo
fibration to contain a vertical cylinder. In the present work, as a
generalization in the sense of singularities, we shall determine the condition
under which a del Pezzo fibration with canonical singularities admits a
vertical cylinder by means of degree and type of singularities found on the
corresponding generic fiber.
