essentially by non-driven elements

Full Title

Removing undesirable matter from the permanent way of railways; Removing undesirable matter from tramway rails (E01H1/00 - E01H6/00 take precedence; ) > Methods or apparatus for removing ice or snow from railway tracks, e.g. using snow-ploughs (operating only on rails or flange grooves E01H8/10) > essentially by non-driven elements