IPC 2013 : E01B 3/18 : Composite sleepers.

IPC2013 > E > E01 > E01B > E01B 3/00 > E01B 3/18[2] > Composite sleepers.
Notes[t] E01 - E06: BUILDING
Notes[g] E01B 1/00 - E01B 26/00: Structure of the permanent way for railways or tramways
E SECTION E — FIXED CONSTRUCTIONS.
E01 CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES.
E01B PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS (derailing or rerailing blocks on track, track brakes or retarders B61K; removal of foreign matter from the permanent way, vegetation control, applying liquids E01H).
E01B 3/00 Transverse or longitudinal sleepers (for switches or crossings E01B 7/22 ); Other means resting directly on the ballastway for supporting rails.
E01B 3/18 · · Composite sleepers.