Bundle Transfer of L-Homology Orientation Classes for Singular Spaces

We consider transfer maps on ordinary homology, bordism of singular spaces and homology with coefficients in Ranicki's symmetric L-spectrum, associated to block bundles with closed oriented PL manifold fiber and compact polyhedral base. We prove that if the base polyhedron is a Witt space, for example a pure-dimensional compact complex algebraic variety, then the symmetric L-homology orientation of the base, constructed by Laures, McClure and the author, transfers to the L-homology orientation of the total space. We deduce from this that the Cheeger-Goresky-MacPherson L-class of the base transfers to the product of the L-class of the total space with the cohomological L-class of the stable vertical normal microbundle.