Comprehensive Rail and Track Related Research    

Dr. Allan Zarembski Papers

Allan M. Zarembski Ph.D., P.E., F.A.S.M.E. - Bio and List of Published Books & Articles

The following articles were reproduced by permission of Railway Track & Structures

Table of Contents

Section 1 - Rail Life

During the past two decades, significant changes in track and rail maintenance practices have occurred. Concurrent with these changes, there have been significant revisions in the criteria used to determine when rail should be replaced in track. The new result of these changing practices has bee the extension of the service life of the rail and an overall reduction in rail maintenance costs.

Changing Face of Rail Replacement
Replacing Branchline Rail
Using Rail Information
More Rail Reliability Issues
Extending Rail Life
Extending Wheel/Rail Life 

Section 2 - Rail Fatigue

As a result of improved rail maintenance practices such as lubrication, rail fatigue has emerged as a key rail replacement criteria for mainline tangent and shallow-curved CWR track. This, in turn, requires the monitoring of the fatigue defects as well as determining a proper point in time for relaying the rail based on the defects formed. Furthermore, it requires a better understanding of the nature, development, and growth of these fatigue defects.

Rail Fatigue - When to Relay
Predicting Rail Defects
Separating Shelling and Spalling
Rail Steel Composition and Fatigue Life
Detection of Rail Steel with Increased Fatigue Potential
Crack Growth in Rails

Section 3 - Rail Wear & Lubrication

In the face of growing evidence of the benefits of rail lubrication­ in extending the wear life of standard carbon rails, increased attention is being focused on the techniques used to apply lubrication to the rail head. Recent test data has shown that effective lubrication can extend the wear life of standard carbon rail by factors of three or more for moderately and heavily curved track. This in turn has led to more careful examination of the practices and technologies surrounding rail lubrication. It has also led to the need for a better under­standing of the problems that can develop as a result of extensive lubrication.

"Greasing" the Way to Savings
Linking Lubrication and Rail Wear, Fatigue
Rail Lubrication Caveats

Section 4 - Rail Grinding

As railway engineering departments have increased their awareness of the true costs associated with the maintenance of critical track components, there has emerged a new philosophy of maintenance for these valuable assets, "preventive maintenance."  Rail in particular has lent itself to this new maintenance approach. Engineering personnel can no longer simply lay the rail and leave it in place until it is time to cascade it into secondary or branch track. Rather, maintenance practices such as rail grinding can be used to extend the service life of this valuable and expensive asset.

Rail Surface Maintenance: Combining Old and New
Profile Rail Grinding
Preventive Rail Grinding
More Rail Grinding Economics
Corrective vs. Preventive Grinding

Section 5 - Track Structures

As the loadings imposed by freight trains have increased, the ability of the track structure to withstand these loadings without excessive deformation, i.e. the "strength" of the track, has become of increasing concern to track maintenance officers. This concern has specifically been directed to the question of whether the traditional track structure can withstand today's greater loadings. It is only through a proper understanding of the load carrying capacity of the track structure can this concern about the adequacy of the track's strength be addressed.

Testing Track Strength
Gage Widening Strength
Modeling Track Component Life
Effect of Track Stiffness on Vehicle Rolling Resistance
Track Modulus vs. Track Structure
Track Modulus Characteristics
Continuous Measurement of Track Gauge Strength
Lateral Ballast Resistance
Track Structure Sensitivities
Vertical Wheel Loads: The Distribution on Cross-Ties
Distribution of Vertical Wheel Loads: Ballast and Subgrade

Section 6 - Track Geometry

The maintenance of proper support and geometry of the track structure is essential to maintaining the integrity of the track. However; defining the quality of track support is extremely difficult, and can result in various interpretations of track support conditions. The use of track quality indices to measure and define the condition of the track and its geometry is a technique that has emerged in recent years as a valuable tool in track maintenance planning and program development.

What is Track Quality?
Planning Through Track Geometry: Part I
Planning Through Track Geometry: Part II
TQIs: Part I - Statistical
TQIs: Part II - Alternatives
Effect of Axle Load on Geometry Measurements

Section 7 - Maintenance Planning

As railroads have become more complex and economically sophisticated, the need to plan and properly execute their system-wide track maintenance programs has also become more complex and difficult. The need to accurately define replacement requirements and to optimize the cost of maintenance has led railroads to the development and use of sophisticated maintenance planning tools. These tools allow for a more accurate forecasting of future component replacement and maintenance needs, as well as a better control of future maintenance costs.

Changes in Track Maintenance Planning
Forecasting Maintenance Needs
Track Replacement Needs as a Function of Traffic Densities

Section 8 - Wheel/Rail Dynamics

Increasing attention is being devoted to the dynamic interaction between wheel and rail and its associated dynamic load environment. This interest has arisen from the growing aware­ness of the damage produced by greater wheel / rail loading, both static, because of heavier cars, and dynamic, due to such diverse factors as wheel and rail surface anomalies, vehicle suspension characteristics, curving performance, etc. By hav­ing a better understanding of the total load environment, dynamic as well as static, the most effective track and vehicle systems can be developed and implemented.

Wheel/Rail Impact Loading
Track Stiffness and Impact
The Effect of L/V
Dynamic Loading of the Track Structure: Part I - Vertical Loads
Dynamic Loading of the Track Structure: Part II - Lateral Loads
Dynamic Loading of the Track Structure: Part III - The Effect of Premium Suspensions

Section 9 - Track Buckling

Because of its potential for catastrophic failure, track buckling is a major area of concern for any maintenance officer who deals with and uses continuously welded rail (CWR). Since there still does not exist an effective technique for detecting locations in track prone to buckling, it is imperative that track forces employ preventive and safe M/W practices to avoid track buckling occurrences. Furthermore, it is important to understand those factors that can lead to or contribute to the occurrence of lateral track buckling.

Vehicle Dynamics and Track Buckling
Temperature and Rail Laying
Train Energy's Effect on Track Buckling

Section 10 - Rail Inspection

Since rail defects can often develop completely within the head or web of the rail, non-destructive testing of the rail is essential in locating these defects before they cause a failure under service conditions. Development of improved rail testing techniques and more effective rail inspection strategies is a continuing pursuit as is optimization of inspection schedules for both heavy- and light-density rail lines.

Economics of Rail Inspection
Misreading Rail Flaw Size
Monitoring the Railhead
Effective Rail Inspection
EMATs for Rail Inspection?
Scheduling Rail Testing

Section 11 - Rail Miscellaneous (Welding / Corrugations)

While fatigue and wear often dominate rail research, other problem areas such as effective rail welding, development of surface defects such as corrugations, etc., also arise on a regular and recurring basis. Railway engineers must also be able to deal with these various (miscellaneous) rail defect areas.

Field Welding Rail
Rail Corrugations on Freight Railroads
Types of Rail Corrugations
Economics of Alternate Repair Welding Techniques

Section 12 - Ties and Fasteners

Proper matching of tie / fastener systems to different operating environments must be based on the adequacy of the system to withstand the specific load environment. Furthermore, a better understanding of the nature of and rate of tie and fastener failure can lead to a more effective maintenance program aimed at maintaining an appropriate and adequate level of tie and fastener strength.

Rail Fastener Performance: What About Strength?
Rail Fastener Performance: The Intangibles
Missing Fasteners vs. Gage Strength
Examining Wood Tie Failure
Extending the Life of Wood Crossties
Wood Tie Life: Part I - Average Tie Life
Wood Tie Life: Part II - Distribution of Failed Ties
Strength Properties of Wood Crossties

Section 13 - Ballast and Subgrade

Ballast, subballast, and subgrade represent a portion of the track structure which is frequently misunderstood and often neglected. Monitoring the condition of the ballast and subgrade is often difficult with limited tools available to maintenance officers. Defining appropriate performance parameters and corresponding tests for railway ballast is particularly important because the economics of ballast use dictates that "local" sources of ballast be used frequently to avoid the significant expense of hauling the material long distances. Thus, the ability to evaluate key performance characteristics of ballast as well as of subballast, and subgrade materials is of real importance to railroads in their ongoing maintenance activities.

The Many Faces of Ballast Testing
Geotextile Performance
The Many Faces of Ballast Fouling
Using Radar to Investigate Roadbed
Cone Penetrometer Testing of Roadbed
Effect of Material Quality Ballast Life
Cost of Ballast Maintenance
Effects of Tamping on Ballast Degradation
Stone Blowing: An Alternate Approach to Track Surfacing
Identifying Sources of Ballast Fouling

Section 14 - Derailments

Derailments represent the ultimate railway catastrophe resulting in high repair and replacement costs, loss of equipment and commodities, and possible loss of human life. Understanding the relationship between track component defects and derailment risk is essential in reducing the incidence of track caused derailments and their associated costs.

Rail Defect Type vs. Derailment Risk
Track-caused Derailments

Section 15 - Life Cycle Costs

Traditionally, railroad product purchasing decisions rest upon two factors: performance and cost. Performance implies the ability of the product or component to carry out its function adequately and effectively, while cost refers both to purchase price and maintenance fees. True cost therefore is not simply the upfront purchase price or first cost of a component but rather the total cost of that component over its life in track, i.e. its life cycle cost. It is this cost that must be examined and compared.

MOW First Costs vs. Life Cycle Costs

Section 16 - Bridges

As the capacity and axle loads of freight equipment continue to increase, the life of the track structure and its components correspondingly decreases. This relationship holds true not only for track components, such as rail, but for railway structures as well, such as steel bridges. Proper understanding of the relationship between traffic loading, bridge stresses, and bridge fatigue will result in an overall effective bridge maintenance and/or replacement strategy, as well as minimization of costs in this potentially high expense area.

Fatigue Life of Steel Bridges
Fatigue Life of Bridges

Section 17 - Turnouts

Turnouts, by their nature and design, see high levels of force and correspondingly require high levels of maintenance. Because of the high costs associated with turnout maintenance, attention is being focused on techniques aimed at improving the dynamic interaction between freight vehicles and the turnout. Such an improvement in dynamic interaction, and the resulting reduction in dynamic wheel / rail forces, is expected to reduce turnout loadings and corresponding turnout maintenance costs, while allowing for an increase in operating speeds through the turnouts.

Reducing Wheel / Rail Forces in Turnouts
Improved Performance from "Premium" Turnouts