US Army Railroad Course Railway Track Maintenance II TR0671
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SUBCOURSE EDITION TR0671 1 RAILWAY TRACK MAINTENANCE II Reference Text (RT) 671 is the second of two texts on railway track maintenance. The first, RT 670, Railway Track Maintenance I, covers fundamentals of railway engineering; roadbed, ballast, and drainage; and track elements--rail, crossties, track fastenings, and rail joints. Reference Text 671 amplifies many of those subjects and also discusses such topics as turnouts, curves, grade crossings, seasonal maintenance, and maintenance-of-way management. If the student has had no practical experience with railway maintenance, it is advisable that RT 670 be studied before this text. In doing so, many of the points stressed in this text will be clarified. In addition, frequent references are made in this text to material in RT 670 so that certain definitions, procedures, etc., may be reviewed if needed. i THIS PAGE WAS INTENTIONALLY LEFT BLANK. ii CONTENTS Paragraph Page INTRODUCTION................................................................................................................. 1 CHAPTER 1. TRACK REHABILITATION............................................................. 1.1 7 Section I. Surfacing..................................................................................... 1.2 8 II. Re-Laying Rail............................................................................ 1.12 18 III. Tie Renewal................................................................................ 1.18 23 CHAPTER 2. TURNOUTS AND SPECIAL SWITCHES......................................................................................... 2.1 29 Section I. Components................................................................................ 2.2 29 II. Location...................................................................................... 2.13 45 III. Construction................................................................................ 2.18 48 IV. Maintenance................................................................................ 2.24 52 V. Special Switches and Track Constructions.............................................................................. 2.29 55 CHAPTER 3. CURVES.............................................................................................. 3.1 62 Section I. Characteristics............................................................................. 3.2 62 II. Superelevation............................................................................ 3.7 66 III. Spirals......................................................................................... 3.12 70 IV. Stringlining................................................................................. 3.16 73 V. Lining an Actual Curve .............................................................. 3.27 85 CHAPTER 4. GRADE CROSSINGS, GUARD RAILS, AND SEASONAL MAIN- TENANCE........................................................................................... 4.1 92 Section I. Crossings at Grade...................................................................... 4.2 92 iii Paragraph Page Section II. Guard Rails................................................................................. 4.7 96 III. Seasonal Problems...................................................................... 4.11 98 CHAPTER 5. SPECIAL PROBLEMS AND MAINTENANCE-OF-WAY MANAGEMENT................................................................................. 5.1 110 Section I. Typical Examples....................................................................... 5.2 110 II. Demolition and Rehabilitation.................................................... 5.9 116 III. Management................................................................................ 5.15 123 APPENDIX I. REFERENCES........................................................................... 133 II. GLOSSARY............................................................................... 134 INDEX................................................................................................................................... 147 *** IMPORTANT NOTICE *** THE PASSING SCORE FOR ALL ACCP MATERIAL IS NOW 70%. PLEASE DISREGARD ALL REFERENCES TO THE 75% REQUIREMENT. iv INTRODUCTION ______________ The first railway coach rolled along the tracks of the Stockton and Darlington Railroad in England in 1825. Ever since, trains have attracted widespread attention not only as a kind of transportation but also because of qualities that endear them to an admiring public. The small boy seeing a real train for the first time shares his thrill with the sedate banker whose hobby is making model rolling stock. This special and often sentimental interest in trains is understandable; trains are big and powerful, and they’re all going somewhere. They’re moving all sorts of people and products to all kinds of places. With cargo unseen and destination unknown, they provide lay observers with a choice of the practical or of the romantic and mysterious upon which to speculate. They excite our curiosity whether we are thinking about a trip, planning a shipment of goods, or just watching a long line of cars speeding along the rails. But what of tracks and roadbeds, those essential parts of all rail systems upon which all train movements depend? Though tracks and roadbeds have their own interesting history and color and their own importance, they do not come in for much attention from the general public, except possibly when new rails are being laid in regions that train service will benefit. Yet without smooth tracks and sound roadbeds, the finest diesel- electric locomotive and the handsomest new Vista Dome train would not go far. Neither would the products that enhance our personal living nor the men and material our armed forces require, for many of these travel by train. Keeping rail lines and rights of way in good condition is, therefore, a primary necessity. It’s an impressively big job, too, involving hundreds of millions of dollars and thousands of workers annually in maintaining and improving trackage in the continental United States. Additional funds are spent each year both for improving materials and equipment used in track work and for research to keep rails and roadbeds ready to adapt to the rapidly changing designs and increasing weight and speed of rolling stock. Advances in track work may be less spectacular than in car and locomotive designs, but to progressive railroading, civilian or military, they are equally important. 1 Improvements in track maintenance have been made. Among them are a more balanced track structure, with the subgrade, ballast, ties, rail, and fastenings so designed that under traffic they do not become permanently distorted; roadbeds stabilized by grouting water pockets with pressurized concrete; and ballast that serves as a reservoir for rain water to keep it from saturating the roadbed. In addition, longer service life for ties is assured through more effective wood preservatives and better tie plates, and new rail sections provide better distribution of stresses and reduce the problem of shelling--flaking of the top surface. New machines and power tools for lightening and speeding track work are increasing in variety and adaptability. One is an all-purpose loader for heavy track jobs; another raises and lowers tracks; a third cleans ballast. In short, mechanization of track maintenance has become a reality. Pick-and shovel methods have been replaced by machines that lay, repair, and maintain track better than ever before. And even maintenance scheduling is being done by automatic data processing. Rail-welding techniques have advanced, and electric butt welding, first tried in Switzerland and later brought to the United States by the Santa Fe, has proved a boon to many lines. In service now are more than 11,000 miles of main-line track consisting of continuous sections of welded rail up to 1 mile long. And such rail is completely “clickless-clackless.” Improved welding techniques foretell nearly universal use of welded rail on main-line tracks. New tools and machinery have made track work easier to perform, and current techniques make for safer, stronger, and smoother track and roadbed. Knowing how and when to use the tools and apply the new methods is nevertheless vitally important. This is the chief concern of the men charged with maintaining track. They must know the elements of track and the general procedures employed in rail and tie replacement, in the upkeep of roadbeds, and in similar jobs. In addition, they must also know how to handle more difficult work, such as the installation of switches, turnouts, crossings, crossovers, curves, and guard rails. They must also know how to cope with many special problems, situations, and devices, and be well versed in maintenance-of-way management, in making track charts, and in programming. How they deal with the more advance and complex phases of rail renewal and right-of-way repair is explained in this text. Reference Text 671 contains five chapters. The first, titled track rehabilitation, is about general repair work done on tracks. But track is not the only part of their section the track maintenance men must maintain. They have to understand how turnouts and special switches are operated and maintained, as discussed in 2 chapter 2. Curved track is more complicated to maintain than straight track, and chapter 3 is devoted to the problems it presents. In addition, the track maintenance men must know how to recognize well-maintained highway grade