Association of American Railroads SAFETY AND OPERATIONS AAR SCALE HANDBOOK 2013 Edition The rules and specifications for construction and maintenance of track scales for the weighing of railroad vehicles. Includes railroad-related hopper scales, belt conveyor scales, mass flow meters, and non-railway vehicle scales. Published by The Association of American Railroads 425 Third Street SW, Washington, D.C. 20024 Printed in U.S.A. Copyright © 2013 by the Association of American Railroads (AAR) Safety and Operations 425 Third Street SW Washington, D.C. 20024 All rights reserved, including the right to reproduce this book in any form. No portion of this publication may be dis- played or otherwise made available to multiple users through any electronic distribution media including but not lim- ited to a local area network or the Internet. No portion may be sold or used for advertisement or gain by any entity other than the AAR and its authorized distributor(s) without written permission from the AAR. ASSOCIATION OF AMERICAN RAILROADS SAFETY AND OPERATIONS 0 SCALE HANDBOOK Current as of January 1, 2013 FORWARD The rules and specifications contained herein apply primarily to weighing systems designed and installed to support railroad locomotives and cars and to weigh the latter. Accordingly, they also specify equipment, procedures, and tolerances for testing track scales intended for static or motion weighing of cars. The rules and specifications meet or exceed the minimum requirements of Handbook 44 as adopted by the National Conference on Weights and Measures (NCWM) under the direction of the National Institute of Standards and Technology (NIST). Handbook 44 is adopted, as law, by most states. As hereby issued, the material included in this handbook is under the jurisdiction of the Technical Services Working Committee of the AAR. Recommendations for updates, changes, and modifications are provided by Committee 34 of the American Railway Engineering and Maintenance of Way Association (AREMA). Committee 34 follows an affirmation program designed to maintain a current AAR Scale Handbook. The affirmation program is a continuous, systematic process whereby the entire handbook is reviewed in segments by members of the committee who have specific expertise in the appropriate subject. The current edition supersedes all previous editions of the AAR Scale Handbook. Part or Section headings indicate the “Amended year” or “Added year” when more than 50% of the part or section is changed. Article headings indicate the “Amended year” or “Added year” when any change is made to the Article. Undated parts, sections, or articles originated prior to 2003. The Chief Engineering Officer of the serving railroad or the Chief Engineering Officer’s designated representative may amend these specifications or any part of them in order to accomplish the stated objectives. Any amendment that does not comply with Handbook 44 or state law should have a consensus agreement in writing by all concerned parties prior to proceeding. AAR SCALE © 2013, Association of American Railroads i THIS PAGE INTENTIONALLY LEFT BLANK © 2013, Association of American Railroads ii ASSOCIATION OF AMERICAN RAILROADS SAFETY AND OPERATIONS 1 SCALE HANDBOOK TABLE OF CONTENTS Part 1 Specifications for the Location, Maintenance, Operation, and Testing of Railway Track Scales . 1–1 Part 2 Basic Specifications for the Manufacture and Installation of Railway Track Scales. 2–1 Part 3 Specifications for the Design and Installation of Low Profile, Pitless, and Instrumented Railway Track Scales . 3–1 Part 4 Rules for the Manufacture, Installation, Location, Operation and Testing of Railway Master Track Scales . 4–1 Part 5 Vehicle Scales. 5–1 Part 6 Hopper Type Scales . 6–1 Part 7 Belt Conveyor Scales (Amended 2009) . 7–1 Part 8 Mass Flow Meters (Added 2010) . 8–1 Part 9 Other Scales . 9–1 Appendix A Definition of Terms (Added 2003). .A–1 Appendix B Standard Forms and Reports . B–1 Appendix C Standard Methods of Test Car Calibration on a Master Scale (Added 2007) . C–1 Appendix D Guidelines for Using a Static Railroad Track Scale (Added 2008) . .D–1 AAR SCALE © 2013, Association of American Railroads iii THIS PAGE INTENTIONALLY LEFT BLANK © 2013, Association of American Railroads iv ASSOCIATION OF AMERICAN RAILROADS SAFETY AND OPERATIONS 0 Part 1 Specifications for the Location, Maintenance, Operation, and Testing of Railway Track Scales — 2013 — TABLE OF CONTENTS Section/Article Description Page 1.1 Locations . 1–3 1.1.1 General Conditions . 1–3 1.1.2 Alignment of Dead and Weigh Rails (Amended 2006) . 1–3 1.1.3 Factors for Motion Weighing. 1–3 1.1.4 Gradient for Static Weighing . 1–4 1.2 Maintenance and Operation . 1–4 1.2.1 Numbering Scales . 1–4 1.2.2 Major Mechanical Scale Repairs . 1–4 1.2.3 Cleaning . 1–4 1.2.4 Rust Prevention for Pivot and Bearing Steels . 1–4 1.2.5 Corrosion Prevention . 1–4 1.2.6 Removal of Ice (Amended 2013). 1–4 1.2.7 Weigh and Approach Rails. 1–4 1.2.8 Weighbeam. 1–5 1.2.9 Standing of Equipment Prohibited. 1–5 AAR SCALE 1.2.10 Restrictions to Use of Weigh Rails on Scales Equipped with Dead Rails. 1–5 1.2.11 Cars on Weigh Rails. 1–5 1.2.12 Use of Sand . 1–5 1.2.13 Stopping Cars on Scales (Amended 2012). 1–5 1.2.14 Inspection by Weighers . 1–5 1.2.15 Security of the Scale House . 1–5 1.3 Testing . 1–6 1.3 Testing . 1–6 1.3.1 Test Frequency . 1–6 1.4 Equipment for Testing . 1–6 1.4.1 Standards of Mass . 1–6 © 2013, Association of American Railroads 1–1 AAR Scale Handbook TABLE OF CONTENTS (CONT) Section/Article Description Page 1.5 Specifications for Railway Track Scale Test Weight Loads (Amended 2008). 1–6 1.5.1 General Guidelines . 1–6 1.5.2 Classification . 1–6 1.5.3 Primary Requirements . 1–6 1.5.4 Composite Railcar . 1–7 1.5.5 Test Weight Railcar . 1–7 1.5.6 Test Weight Railcart . ..