LREE-9316C.pdf

lree9316c

MASSACHUSETTS

BAY

TRANSPORTATION

AUTHORITY

TECHNICAL SPECIFICATION

LREE - 9316

SPECIFICATION for REPROFILING TIRES

ISSUED: 12/09/93

REVISION A:

REVISION B:

REVISION C:

06/09/94

05/07/98

03/22/02

LIGHT RAIL EQUIPMENT ENGINEERING

LREE – 9316C

Specification for Reprofiling Tires lree-9316c

TABLE OF CONTENTS

DESCRIPTION PAGE #

1.0 SCOPE

2.0 APPLICABLE DOCUMENTS

3.0 VARIATIONS

3.1 Conflicts

3.2 Oral Statements

4.0 REQUIREMENTS

4.1 General

4.2 Workmanship

4.3 Handling

4.4 Hardness

4.5 Mechanical Dimensions

4.6 Circular Runout

4.7 Minimum Material Removal

4.8 Diameter

4.9 Surface Finish

4.10 Marking

4.11 Protective Coating

4.12 Witness Marks

4.13 Quality

5.0 PREPARED BY

6.0 APPROVED BY

7.0 REVISIONS

1.0 SCOPE

This specification establishes the requirements for the reprofiling of metal tires used on Light

Rail Vehicles.

2.0 APPLICABLE DOCUMENTS

The following documents form part of this specification to the extent specified herein:

2.1 MBTA Drawing No. 47639, Rev. B entitled Green Line Wheel Profile (See Page 8)

2.2 Individual pages from the American Railroad Wheel and Axle Manual, Edition 11

(See Pages 9-11 and 13-16)

2.3 MBTA Drawing No. 47652, Rev. B entitled Contour Gage (Green Line Wheel

Profile) (See Page 12)

3.0 VARIATIONS

3.1 Conflicts

Any conflicts shall be referred in writing to Light Rail Engineering for resolution.

3.2 Oral Statements

Oral statements by any person or persons shall not be permitted in any manner or degree to modify or otherwise affect the requirements of any portion of this specification.

4.0 REQUIREMENTS

4.1 General

4.1.1 Proposals offering equipment not meeting the entire scope of this specification shall not be accepted.

4.1.2 Abnormal tire conditions shall be brought to the attention of Light Rail

Engineering prior to machining of the tires.

4.1.3 Tires provided to the machine shop shall be inspected for defects (see AAR

Manual). Any tire with a defect that cannot be removed by machining within the prescribed tolerances shall be scrapped immediately in order to prevent loss of time and money.

4.1.4 Depending upon current requirements, 3 1/2 or 4 inch width tires shall be provided by Light Rail Equipment Department to the machine shop selected to reprofile tires.

4.1.5 The quantity of tires provided shall be determined by Light Rail Equipment

Department.

4.2 Workmanship

4.2.1 Tires shall be processed in a careful and workmanlike manner in accordance with good design and sound practice and shall be free from defects that effect life, serviceability and/or appearance.

4.2.2 All workmanship shall be of high grade and shall conform to the best machine tool industry practices in all respects for railway passenger cars and surface rail vehicles.

4.2.3 All surfaces shall be smooth, free from burrs, fins and other sharp projections.

4.2.4 No metal rollover shall be present on the front surface of the tire (side opposite flange).

4.2.5 No nicks, voids, scratches, slag, spalling or other imperfections shall be present on tire circumference.

4.2.6 Imperfections on the flange, including the back, are unacceptable.

4.2.7 The throat radius of the tread contour shall be free of any step, gouge, and/or blemish after reprofiling.

4.2.8 A smooth transition from the tire outer circumference to the front face and the back side of the flange to the back of the tire shall be present.

4.2.9 Step indexes on reprofiled surfaces are unacceptable and are cause for rejection.

4.2.10 No flat spots on the outer circumference of the tire shall be present.

4.2.11 Shelled, galled thread and/or subsurface defects discovered during machining shall be evaluated by Light Rail Engineering prior to proceeding.

Acceptability is defined in the American Railroad Wheel and Axle Manual, Edition 11 or later.

4.2.12 If the tire is rejected in the reprofiling process, the tire must be segregated and marked as scrap. Tires that are scrapped shall be marked with an "S" on both sides of the tire using white or yellow paint stick. Scrapped tires shall be returned to the MBTA.

4.2.13 The tires shall be delivered clean with all cutting oils and grease removed.

Any chemical used to clean the tires shall not cause damage to the tire material.

4.3 Handling

4.3.1 The tires shall be adequately protected during shipping, handling and storage to prevent damage.

4.3.2 The machine shop selected to reprofile tires is responsible for pick-up and delivery of the tires.

4.4 Hardness

The method of machining shall not affect the wheel hardness. The hardness of the tire after final machining shall be 321-363 HB.

4.5 Mechanical Dimensions

The tire profile shall be machined according to attached drawing 47639, Revision B.

(See Page 8)

4.6 Circular Runout

4.6.1 The circular runout of the tire outer diameter shall be to within 0.015 inches

TIR of the tire inner diameter.

4.6.2 The circular runout of the tire backside (flange side) shall be to within 0.030 inches TIR of the tire inner diameter.

4.7 Minimum Material Removal

4.7.1 A minimum amount of tire material removal to preserve tire life is required.

4.7.2 The machine shop has the responsibility of notifying the MBTA if the 24.300 inch minimum diameter cannot be achieved prior to tire reprofiling.

4.8 Diameter

4.8.1 The tire diameter shall not be machined to less than 24.300 inches.

4.8.2 Diameter measurements shall always be taken at the measurement or taping position of the tire outer diameter at the root flange of the radius for consistent readings. (Reference 47639, Revision B, Page 8)

4.8.3 The diameter of each pair of tires shall be machined to within 0.012 inches maximum for matching the tire pair on the same axle.

4.8.4 The diameter of two (2) pair of tires shall be machined to within 0.030 inches maximum for matching the four (4) tires on the same truck.

4.8.5 The two (2) pair of tires , machined as described above, shall be packaged in a lot of four (4) for truck installation.

4.9 Surface Finish

The surface finish of the tire on the reprofiled surfaces shall be Ra 350 micro-inches.

4.10 Marking

The finished tire diameter shall be marked with permanent ink on the front surface of the tire (side opposite flange).

4.11 Protective Coating

The reprofiled surface shall be coated with a protective coating to prevent rust and/or oxidation during shipment and storage. The coating shall not be a material, such as a lubricant, which may effect the braking rate of the vehicle when the tires are installed.

4.12 Witness Marks

Witness marks remaining in the tire after machining are not permitted.

4.13 Quality

4.13.1 The tire profile shall be inspected and accepted or rejected according to

MBTA standards.

4.13.2 The MBTA reserves the right to conduct testing and mechanical measurements of the tires and to reject a tire lot if a sample tire from that lot does not meet the requirements of this specification.

4.13.3 The usage of the tire is a safety sensitive application therefore ultimate tire integrity is required.

4.13.4 Traceability to the machine shop that has reprofiled the tires shall be done by permanently marking the tire on the front surface with the machine shop identification.

4.13.5 A contour gage shall be provided, by the machine shop that has reprofiled the tires, for Light Rail Engineering inspection of the tires. The gage shall be in accordance with MBTA Drawing No. 47652, Rev. B (See Page 12) and shall become property of the MBTA.

4.13.6 The contour gage shall be utilized by Light Rail Engineering to verify the correct tread and flange for the reprofiled tires.

4.13.7 The MBTA Quality Assurance designee, or Light Rail Engineering representative shall have the authority to identify and record, initiate or recommend disposition, verify correction, and to prevent further processing, delivery or installation of tires on vehicles until any reprofiling deficiency or unsatisfactory condition has been resolved.

7.0 REVISIONS

SECTION DATE DESCRIPTION REVISION

2.1 06/09/94 Added Contour Gage A

4.1 06/09/94 Added statement on inspection for defects A

4.2 06/09/94 Added statement on throat radius A

4.2 06/09/94 Added statement on scrapping the tire A

4.7 06/09/94 Changed minimum dia. from 24.5 inches to 24.3 inches A

4.8 06/09/94 Changed diameter from 24.5 to 24.3 inches A

4.13 06/09/94 Changed no go gauge to contour gage A

4.13 06/09/94 Added statement on QA or LREE representative A

Entire 05/07/98 Update to current format B

Procedure

2.0 05/07/98 Updated MBTA Drawing Numbers and added

B numbering 2.1.1 thru 2.1.3

4.5.1 05/07/98 Added "Rev. B" to Drawing No. B

4.8.2 05/07/98 Added "Rev. B" to Drawing No. B

4.13.5 05/07/98 Added "Rev. B" to Drawing No. B

03/22/02 Update specification to current format C