Wheels & Axles
49 CFR Sec. 173.31(d) Examination before shipping. (1) No person may offer for transportation a tank car containing a hazardous material or a residue of a hazardous material unless that person determines that the tank car is in proper condition and safe for transportation. As a minimum, each person offering a tank car for transportation must perform an external visual inspection that includes: (iii) For missing or loose bolts, nuts, or elements that make the tank car unsafe for transportation;
AAR Rule 41 - Wheels.
A. Wear Limits, Gaging, Cause for Renewal.
Wheel Defect Gage No. 34401 or 34401A
1. Condemnable at anytime.
a. Thin flange: 15/16 inch thick or less, apply gage as follows
b. Vertical flange: Flat vertical surface extending one inch of from tread. :
c. High flange: Height is 1 1/2 inches or more above the approximate center line of tread.
d. Cracked or broken flange-any length. Chipped flange must exceed 1 1/2 inch in length by 1/2
inch in width and not a mere flaking of surface.
e. Cracked or broken rim. Chips broken from the uniform curling over of the outer edge of the
rim around the entire wheel are not considered a defect.
f. Shattered rim (break shows a smooth fracture)
g. Spread rim.
h.(1) Thin rim, 3/4 inch or less for 30 and 33 inch wheels.
(2) Thin rim 7/8 inch or less for 28, 36 and 38 inch wheels.
i. Shelled tread: When the shell or spall is 3/4 inches diameter or larger and the shells or spalls
are more or less continuous around the periphery of the wheel or whenever any shell or spall is 1
inch or more in diameter the wheel must be removed from service."Islands" of original tread
surface metal contained in the shell or spall will not be considered as part of the area of the shell
or spall.
j. Built up tread: A wheel is condemnable whenever the tread has built-up metal 1/8" or higher
than the wheel tread.
k. Grooved tread: One or more grooves worn to a depth of 1/8 inches or more.
l. Thermal cracks: Transverse cracks.
m. Cracked or broken plate:
n. Holes in plate, drilled. burned with torch or electric arc.
o. Loose: Any wheel showing evidence of movement on the wheel seat or oil seepage on the
back plate from inside of wheel fit.
q. Wrong diameter wheel, not standard to car.
r. Out of gage.
v. Scrape, dent or gouge anywhere in the wheel surface more than 1/8 inch deep.
1. Slid flat:
a. Two inches or over in length.
b. Two or more adjoining spots each 1 1/2 inch or over in length.
2. Wheels overheated as a result of fire.
E. 3. For other than 33 inch wheels, car must be stenciled to indicate wheel size standard to car.
4. Wheels must not be painted.
Hub (wheel)
AAR Rule 41 - Wheels.
A. Wear Limits, Gaging, Cause for Renewal.
Wheel Defect Gage No. 34401 or 34401A
1. Condemnable at anytime.
n. Holes in plate, drilled. burned with torch or electric arc.
o. Loose: Any wheel showing evidence of movement on the wheel seat or oil seepage on the back plate from inside of wheel fit.
q. Wrong diameter wheel, not standard to car.
r. Out of gage.
Axle
AAR Rule 43 - Axles
A. Wear Limits, Gaging, cause For Renewal.
1. Limits of Wear, applicable on shop track.
2. Additional cause for renewal.
a. Broken.
b. Damage between wheel seats 1/8 inch or deeper.
c. Damage due to overheating.
d. Wrong size axle (not standard to car).
e. Evidence of welding.
f. Axle bent unless associated with unfair usage.
AAR Rule 41 - Wheels.
A. Wear Limits, Gaging, Cause for Renewal.
.
o. Loose: Any wheel showing evidence of movement on the wheel seat or oil seepage on the back plate from inside of wheel fit.
q. Wrong diameter wheel, not standard to car.
r. Out of gage.
Rule 88 - Mechanical Requirements for Acceptance.
A. At any time
4. Axles
a. AAR standard (raised wheel seat) or AAR alternative standard (black collar) axles are required.
Tread (wheel)
AAR Rule 41 - Wheels.
A. Wear Limits, Gaging, Cause for Renewal.
Wheel Defect Gage No. 34401 or 34401A
1. Condemnable at anytime.
1. Slid flat:
a. Two inches or over in length.
b. Two or more adjoining spots each 1 1/2 inch or over in length
k. Grooved tread: One or more grooves worn to a depth of 1/8 inches or more.
l. Thermal cracks: Transverse cracks.
Flange (wheel)
AAR Rule 41 - Wheels.
A. Wear Limits, Gaging, Cause for Renewal.
Wheel Defect Gage No. 34401 or 34401A
1. Condemnable at anytime.
a. Thin flange: 15/16 inch thick or less, apply gage as follows
b. Vertical flange: Flat vertical surface extending one inch of from tread. :
c. High flange: Height is 1 1/2 inches or more above the approximate center line of tread.
d. Cracked or broken flange-any length. Chipped flange must exceed 1 1/2 inch in length by 1/2 inch in width and not a mere flaking of surface.
e. Cracked or broken rim. Chips broken from the uniform curling over of the outer edge of the rim around the entire wheel are not considered a defect.
f. Shattered rim (break shows a smooth fracture)
g. Spread rim.
i. Shelled tread: When the shell or spall is 3/4 inches in length and in width or larger and the shells or spalls are more or less continuous around the periphery of the wheel or whenever any shell or spall is 1" or more in length and in width, the wheel must be removed from service.
j. Built up tread: A wheel is condemnable whenever the tread has built-up metal 1/8" or higher than the wheel tread.
Roller Bearing, Roller Bearing Retainer (Frame Key) and Fasteners
AAR Rule 36 - Roller Bearings
A. Wear Limits, Gaging for Renewal.
1, b. Minor Derailment. Derailed trucks on empty or full cars involved in a derailment at a speed of not over 10 miles per hour or which have not moved on the ground more than 200 feet. Inspect bearings as follows.
1. Remove wheel sets
2. Bearing must be sufficiently clean to permit adequate inspection of all external parts.
3. Carefully inspect the outer cup for cracks or breaks.
4. Inspect for loose front or back seals.
5. Inspect for loose or missing end cap screws.
6. Insect for loose backing rings.
7. Inspect bearings in accordance with the guidelines in Rule 36, A.3.
8. Check for bent axle in accordance with Rule 43, E.5.
9. Inspect end cap for cracks, broken ears or nicks, dents and gouges in excess of 1/8" deep.
10. If these checks are satisfactory, continue wheels in service. Otherwise the bearings must be removed, disassembled and inspected for damage.
2. Overheated, submerged, or welding arcing damage.
4. External parts visibly cracked, broken or bent.
8. Wrong size roller bearing not standard to car.
10. Loose Backing Ring. A backing ring that can be moved by hand is considered to be loose.
11. Loose, Cocked or Damaged seal.
a. Seal can be rotated or moved by hand with use of a suitable probe to see if it is cocked or out of position.
b. Seal is visibly damaged.
12. One or more visibly loose or missing cap screws, missing locking plate, or missing lubricant fitting or plug except by design.
AAR Rule 26 - Lubrication, General Regulations for Periodic Lubrication Roller Bearings
A. Cause for Attention.
(Non-Rotating Housing End Covers)
1. Over Date
a. After expiration of 18 months.
b. After expiration of 17 months when car is on repair track or in transportation yards.
c. Wheels changed and lubrication date is 12 months or over-lubricate only bearings not changed.
2. Stenciling missing, incorrect or indistinct.
3. Expiration of time limit is defined as being after the expiration of the period specified in section A.1.
E. General Information.
1. Each railroad is responsible for the lubrication of all cars on its line.
2. Owner is responsible for failure of roller bearings with end caps that rotate.
5. Owner is responsible for periodic lubrication of roller bearings with non-rotating housing end covers after the expiration of time limits regardless of circumstances.
6. Do not lubricate bearings with end caps that rotate.
AAR Rule 88 - Mechanical Requirements for Acceptance.
A. At any time
10. Roller Bearings
a. All cars must be equipped with AAR approved roller bearings listed in AAR Rule 36, Section B, Groups A-D.
Roller Bearing Adapter
AAR Rule 37 - Roller Bearing Adaptor
A. Wear limits, gauging cause for renewal.
1. Cracked, broken, missing.
2. Adaptor worn to the extent that a bright narrow wear band is visibleon the bearings outer ring at either end as shown below.
3.a. If the crown on top of adaptor has worn to such a condition that frames would wear on relief portions , adapters must be replaced.
When crowns have worn to the extent that truck frame contacts any relief area adapter must be scrapped.
4. Wrong size adapter not standard to car.