AAR Circular Letter
C-9551

November 21, 2002

Circular Letter

(c-9551)

 

Subject: Implementation of New AAR Standard S-286:  Specification for 286,000# GRL Cars for Unrestricted Interchange Service

TO THE MEMBERS AND PRIVATE CAR OWNERS                                                                                             File Number: CC-170.7.1

Comments on a proposed AAR Standard S-286, SPECIFICATION FOR 286,000 LBS. GROSS RAIL LOAD CARS FOR FREE/UNRESTRICTED INTERCHANGE SERVICE,  were solicited in Circular Letter c-9515 dated September 20, 2002.  The proposed Standard was reviewed and discussed in detail during a September 24 panel session in the Chicago meeting of the Mechanical Association Railcar Technical Services (MARTS).  In addition to valuable input received at the MARTS session, AAR received many written comments.

All of the comments were reviewed by the Equipment Engineering Committee (EEC) and received due consideration.  The EEC was responsive to the concerns over car owner/car builder lead times and to many of the technical issues raised.  The Technical Services Working Committee, at its November 7th meeting, adopted the proposed Standard S-286 (with revisions recommended by the EEC) effective for all new freight cars delivered after December 31, 2003.  Early, voluntary compliance with the new standard is strongly encouraged.

Please note that cars built with GRLs > 268K after 2003 not meeting new Standard S-286 are restricted to controlled interchange service and may therefore be operated only through bilateral agreements.

The new Standard is appended to this circular.

Highlights / Quick Reference:

Revisions from September 20th Circular Letter:

Editorial revisions to AAR Standard S-259 and by the Arbitration & Rules Committee to Interchange Rules 70 and 88 are being finalized and will be announced in a separate circular.

The new standard will enhance the mechanical performance of heavy axle load cars and reduce the forces at the vehicle/rail interface.  This the "Stress State" of the railroad will be reduced.

Please insert this circular in your copy of Section C of the Manual of Standards and Recommended Practices

Sincerely,

Patrick T. Ameen

 

Association of American Railroads

Manual of Standards and Recommended Practices

Car Construction - Fundamental and Details

 

SPECIFICATION FOR 286,000  LBS. GROSS RAIL LOAD CARS FOR

FREE/UNRESTRICTED INTERCHANGE SERVICE

 

Standard S-286-2002

 

Adopted November, 2002

 

Effective:  January 1, 2004

 

1.0 SCOPE

 

This specification applies to all new 4-axle freight cars built after December 31, 2003 that are designed and designated to carry a gross rail load (GRL) greater than 268,000, up to and including 286,000 lbs. Existing freight cars and those rebuilt, newly designated for increased GRL, or modified per Office Manual Rule 88 will be qualified for free unrestricted interchange service provided they meet all requirements of this specification.  Unless specifically addressed in this Standard, all appropriate AAR Standards must be met in the design, building and operation of cars in free/unrestricted interchange with a GRL greater than 268,000 lbs.  The following specifications outline the requirements for free/unrestricted interchange cars.  For purposes of the Standard, any reference to 286,000 lbs. shall include all 4-axle cars with a GRL greater than 268,000 lbs., up to, and including 286,000 lbs. Tank cars have additional requirements; refer to AAR Specification 2.5, MSRP M-1002.

 

 

2.0 REQUIREMENTS

 

2.1 CARBODY

 

2.1.1 Design Loads

 

Design of the carbody (including the sides, ends and underframe unless otherwise noted) shall be based on a GRL of 286,000 lbs.  Where standard design loads are not  specified in M-1001 for  286,000 lbs. GRL, then design loads for 100-ton cars in AAR Specification M-1001 should be used, and those loads should be multiplied by the factor 1.09.  When design loads are not specific to car GRL, the existing specifications will govern unchanged.  Examples of the latter are the 50,000 lbs. vertical coupler load of Section 4.1.5.3 and impact test coupler force of 1,250,000 lbs. in Section 4.1.10.

 

2.1.2 Fatigue Design

 

A fatigue analysis in accordance with Chapter VII of M-1001 must be performed on all cars built to this specification.  When applying fatigue design criteria to a 286, 000 lbs. design, 263,000 lbs GRL related REPOS loading multiplied by 1.09 must be used for new car analysis, if 286,000 GRL REPOS are not specified.  Cars built prior to the effective date of this specification and increased in gross weight through modification or on the basis of original construction are not required to have a fatigue analysis performed.  All cars built for 286,000 lbs. GRL after the effective date of this specification must have a minimum computer fatigue life of 1,000,000 miles.  High utilization cars must have a minimum computer fatigue life of 3,000,000 miles.

 

2.2 BRAKE SYSTEM

 

Brake Systems must meet the braking ratios of S-401 based on GRL.

 

2.3 BEARINGS

 

The bearing size of 6 1/2 X 9, 7 X 9 or 7 X 12 to be applied

 

2.4 AXLES

 

The axle size of 6 1/2 X 9, 7 X 9, 7 X 12 to be applied.  Axles are to be ultrasonically tested per AAR Specification M-101.  Axles with machined grooves at the inboard seal wear ring/journal contact area shall not be used.

 

2.5 WHEELS

 

Wheels are to be new 36 inch mounted on 6 1/2 X 9 axles and bearings or new 38 inch mounted on 7 X 9 or 7 X 12 axles and bearings.  Wheels are to be curved-plate, Class C

 

2.6 DRAFT SYSTEM

 

2.6.1 Draft Components

 

Couplers, yokes, followers and draft keys must be of Grade E steel.

 

2.6.2 Draft Gears

 

Draft gears must have a minimum of 3 1/4 inch travel and conform to AAR M-901E, M-901G, or M-901H latest revision or cars must be equipped with hydraulic cushioning units in accordance with Office Manual Rule 88

 

2.7 SPRINGS

 

Spring groupings are to be as specified in S-3014 or S-3015.  The Equipment Engineering Committee may approve alternative spring arrangements.

 

2.8 TRUCKS

 

2.8.1 Truck Performance and Castings

 

Truck shall have Preliminary, Conditional or Full Approval under AAR Truck Performance Specification M-976, latest issue.  Proponent may make application for approval to the Equipment Engineering Committee for a specific car and suspension combination if proponent can show that car and suspension performance are equal to or better than the performance outlined in M-976.  All the limiting nominal design dimensions for trucks contained in AAR Standard S-302 shall be adhered to.  Castings shall meet the requirements of AAR Standards M-202, M-203 and M-210.  Where standard design loads are not specified for 286,000 lbs. GRL, then the current test loads provided for axle loading of 6 1/2 X 12 journal X 1.09 shall be used for castings in 286,000 service.  Casting manufacturer to certify truck castings are designed to 286,000 lbs. GRL.

 

2.8.2  Side Bearings

 

Cars are to be equipped with constant contact side bearings in accordance with AAR Specification M-948 and Office Manual Rule 88.

 

2.9 STENCILING

 

Cars meeting the requirements of this specification are to be stenciled with a load limit that equates to GRL minus the lightweight or have a reduced load limit starred in accordance with Interchange Rule 70.