E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
E01B3/00—Transverse or longitudinal sleepers; Other means resting directly on the ballastway for supporting rails
E01B3/16—Transverse or longitudinal sleepers; Other means resting directly on the ballastway for supporting rails made from steel
E01B3/26—Transverse or longitudinal sleepers; Other means resting directly on the ballastway for supporting rails made from steel combined with inserts of wood artificial stone or other material