| B | SK | PERFORMING OPERATIONS; TRANSPORTING |
| B61 | KL | RAILWAYS |
| B61B | UKL | RAILWAY SYSTEMS; EQUIPMENT THEREFOR NOT OTHERWISE PROVIDED FOR (lifts or hoists, elevators, escalators, moving walkways B66B) [4] |
| B61C | UKL | LOCOMOTIVES; MOTOR RAILCARS (vehicles in general B60; frames or bogies B61F; special railroad equipment for locomotives B61J, B61K) |
| B61D | UKL | BODY DETAILS OR KINDS OF RAILWAY VEHICLES (vehicles in general B60; adaptation of vehicles to special systems B61B; underframes B61F) |
| B61F | UKL | RAIL VEHICLE SUSPENSIONS, e.g. UNDERFRAMES, BOGIES OR ARRANGEMENTS OF WHEEL AXLES; RAIL VEHICLES FOR USE ON TRACKS OF DIFFERENT WIDTH; PREVENTING DERAILING OF RAIL VEHICLES; WHEEL GUARDS, OBSTRUCTION REMOVERS OR THE LIKE FOR RAIL VEHICLES (for vehicles in general B60; axles or wheels B60B; vehicle tyres B60C) |
| B61G | UKL | COUPLINGS SPECIALLY ADAPTED FOR RAILWAY VEHICLES; DRAUGHT OR BUFFING APPLIANCES SPECIALLY ADAPTED FOR RAILWAY VEHICLES |
| B61H | UKL | BRAKES OR OTHER RETARDING APPARATUS PECULIAR TO RAIL VEHICLES; ARRANGEMENTS OR DISPOSITIONS OF BRAKES OR OTHER RETARDING APPARATUS IN RAIL VEHICLES (electrodynamic braking of vehicles B60L, in general H02K; arrangements in rail vehicles for adjusting wheel-braking force to meet varying vehicular or permanent-way conditions B60T 8/00; transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive, brake systems incorporating such transmitting means, e.g. air-pressure brake systems, B60T 13/00; construction, arrangement or operation of valves incorporated in power brake systems B60T 15/00; component parts, details or accessories of brake systems B60T 17/00; brakes in general F16D) |
| B61J | UKL | SHIFTING OR SHUNTING OF RAIL VEHICLES (shifting vehicles in general B60S; marshalling systems B61B) |
| B61K | UKL | OTHER AUXILIARY EQUIPMENT FOR RAILWAYS (energy-storing brakes B61H; protection of permanent way against weather influences E01B; rail cleaning, snow ploughs E01H) |
| B61L | UKL | GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC (brakes or auxiliary equipment B61H, B61K; point or crossing construction E01B) |