October 21, 1998

CIRCULAR LETTER

(c-8933)

Subject:      Implementation of Changes to Section G II, Rules 1A8 and 1A11.

TO MEMBERS AND PRIVATE CAR OWNERS

File Number: TWBL-16.3

TWBL-23.1

Please refer to Circular Letters c-8692, dated January 23, 1997 and c-8819, dated November 26, 1997. These two Circular Letters proposed modifications of Section G II, Rules 1A8 and 1A11. Industry comments regarding these changes were received in accordance with S-050 and were duly considered by the Wheels, Axles, Bearing, and Lubrication Committee. The modification of Rule 1A11 was also considered by the Technical Services Working Committee.

The Committees have approved the attached changes to be effective January 1, 1999. This is your authority to replace pages G II – 1 and G II – 2 in your Manual of Standards and Recommended Practices with the attached pages.

Internet only users can call Kathy Pacheco at 877-999-8824 (toll free) for paper copies of the changes.

Sincerely,

Thomas Stahura

Rule 1A1 Axles must meet the specified machine tolerances within this manual. When specified machine tolerances cannot be maintained, lathes must be adjusted or repaired.

Rule 1A2 New and converted axles (as defined in Rule 2A2(e)) must conform to dimensions and specifications as shown in this manual (see Figures 4.3, 4.4, 4.6, 4.12, 4.13, 4.16 and 4.17). Secondhand axles must conform to dimensions and specifications as shown in this manual (see Figures 4.9, 4.10, 4.11 and 4.15-4.17).

Rule 1A3 If axle is stenciled "Overheated – Scrap" or if journal surface or end of axle has any discoloration due to overheating (light straw, dark straw or any departure from the normal bright finish) or if circumferential checks or cracks are found in the journal, the axle must be scrapped. Journal must be mutilated or axle must be suitable marked to prevent reuse.

When roller bearings are removed from axles marked "RB Overheated," the axle must be inspected and if found to be overheated the journal must be mutilated or the axle suitable marked to prevent reuse.

Rule 1A4 Centering holes in the ends of axles must form an angle of 60 degrees and be in accordance with Figure 4.12. Any burrs around centers must be removed. Centering holes must be wiped clean before placing the axle in the lathe in order that journals and wheel seats will no be eccentric and grit will not cut the lathe centers.

Rule 1A5 Files may only be used to break sharp edges of dust guard seats, end of axles and to work down upset ends or surface defects of roller bearing axles providing the bearing seat diameters are not reduced below minimum and the surface roughness meets specifications. Files must not be used on fillets or wheel seats.

Rule 1A6 Wheel seats or secondhand axles need not be returned prior to mounting provided they meet specifications of Rules 1A2, 1A6 and 1A7. Wheel seats requiring correcting may be machine cut, ground, rolled or polished with abrasive cloth (80 grit or finer). Any depression, circumferential scores or checks, damage, injury, longitudinal channelway or crack in the wheel seats must be removed. To insure true entry of the axle into the wheel bore a taper must be turned on the outer end of the wheel seat starting at least ¹/₃₂" less than wheel seat diameter and extending a maximum of ½".

Rule 1A7 At the beginning of each shift, from each lathe in service, an axle wheel seat must be checked at not less than three points in its length and on two different diameters at each of these points to insure rotundity. Measurements shall be taken a minimum of 1 inch from the wheel seat outboard edge, at the center and 1 inch from the wheel seat inboard edge. The variation for any two of these measurements must not exceed 0.002". As the wheel seat is measured from the journal end to the axle center, at no point should the dimension decrease. Outside micrometer calipers must be used for measuring axle wheel seats.

Rule 1A8 Wheel seats and journals of loose axles which have previously been in freight car service and the entire length of loose axles which have previously been in other service must be magnetic particle tested by the wet method before remounting. Axles with cracks must be repaired prior to returning to service. Inspectors must be qualified and certified to ASNT level I for magnetic particle inspection. Machinery must be set up and operated in accordance with documented procedures. The manufacturers’ instructions should be followed unless departure is both justified and documented.

A detectability test must be conducted and documented prior to each shift of operation to ensure that the machinery in use is set up and operating properly and that the operator can detect a circumferential crack that is not otherwise visible to the naked eye. The test is designed to verify the effectiveness of light, the bath solution and the magnetic field during normal operation but must be conducted for the worst case scenario as follows:

• Bath solution concentration is highly dependent on agitation, therefore delectability must be check under normal conditions and not directly after manual agitation.
• The test piece (s) must be thoroughly cleaned of previous test indications and verified with the light before starting the test.
• The test piece (s) must be positioned as far away from the centerline of the magnetic field as a potential crack could be during normal operation. (e.g. if the center of the magnetic field is at the dust guard fillet, the test piece (s) should be positioned at the inboard edge of the wheel seat or at the end of the axle journal.)
• In the event that a detectability test fails, all axles processed since the last successful test must be recalled and reinspected after the problem is resolved. Several cracks of varying depths are recommended so that weakening of the solution, light intensity and/or magnetic field can be detected early and action taken before the limit is reach.

Axles must be demagnetized after magnetic particle inspection to less than 8 gauss at the axle surface and verified with a calibrated magnetic field strength indicator.

Rule 1A9 Axles having drive devices or brake discs mounted on the body of the axle between wheel seats must have the body of axle magnetic particle tested by the wet method when such wheel assemblies are processed through the wheel shop for driving device attention (see 2E3). It is not necessary to remove the brake discs or drive devices before testing.

Rule 1A10 Welding on axles is not permitted and any axle showing welding or cutting torch damage is scrap. Only electro-chemical metal deposition processes, covered in 1C6, are approved repair techniques.

Rule 1A11 Any nicks, gouges or deep scratches less that 1/8" deep, as measured from the original body contour, must be ground out and smoothly blended into the contour of the axle body. Areas repaired in this manner must be magnetic-particle tested. Any axle body machined (including grinding) must be magnetic particle tested after machining. Defects found, as the result of magnetic particle inspection must be removed without going below specification. Do not make nicks, pinch marks, chisel marks or stamping, etc., in the bodies of the axle, including axles having as forged bodies.

Rule 1A12 When axle markings consisting of manufacturer’s brand, date, serial number, heat number and grade of axle (U,D,F, etc.) will be obliterated due to refinishing, a record of this information shall be made and the marking restored after refinishing by cold stamping ¼" high figures shown in Figure 4.13.

Rule 1A13 Shops finish machining new axles must mark these in accordance with Figure 4.13, Note 12.

Rule 1C1 Maximum allowable runout between axle wheel seat and journal is 0.015" total dial indicator reading, see Figure 4.9. When runout exceeds this, axle wheel seats must be turned or centers corrected to bring axle wheel seat and journal runout within this tolerance.

Rule 1C2 Unmounted secondhand axles and any mounted axles involved in a major derailment must be checked on centers or by the alternate method, as shown in Figure 4.15, for bent condition using dial indicator on each journal and obtaining a reading near end of journal and near journal fillet. If total dial indicator reading between end and fillet on either journal differs more than 0.010" in one complete revolution the axle must be scrapped. Journal must be mutilated or axle must be suitable marked to prevent reuse.

Rule 1C3 Roller bearing axles with mounted wheels which have been in derailment must be checked for bent condition with roller bearing removed. This check, including tolerances, must be the same as specified in 1C2.

Rule 1C4 Cleaning Before attempting to qualify axles, the axle ends, journals, journal fillets, dust guard seats and wear ring grooves must be thoroughly cleaned.

• Abrasive method may be used provided it is 80 grit of finer.
• Fillets with fretting that cannot be removed with abrasive cloth may be refinished by grinding or machine cutting, providing the "U" dimension is not reduced below minimum length as checked with the gage shown in Figure 5.21.