Browsing by Author "Palese, J. W."
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Item BNSF Tests Risk-Based Ultrasonic Detection(Railway Track & Structures Magazine, 2001-02) Palese, J. W.; Zarembski, Allan M.; Patel, P. K.As the railroad industry continues its focus on increased safety, rail defects and resulting rail caused derailments, have become an important area of interest. Analysis of FRA statistics on reportable mainline derailments, attributed to rail defects, shows an overall industry increase in reported derailments per billion gross ton mile (BGTM) of 4% in the period 1997 to 1999 [1,2]. This trend is illustrated in Figure 1 together with the corresponding increase in the average cost of rail related derailments for that same time period of more than 40%. Examining the FRA derailment data further, Figure 2 shows the distribution of derailments by rail defect type along with the average cost of derailment for that defect type. This figure clearly shows that the most predominant cause of rail related derailments is the transverse defect or TD class of defects, with the Detail Fracture (DF) representing the second most common cause of rail related derailments. For the entire range of rail defects, the average derailment cost varied from $200,000 to $1,400,000 depending on defect type, with an overall average of the order of $400,000. Note, this is FRA reportable cost only, the actual cost of the derailment, which could include loss of lading, train delays, or train rerouting, can be double that amount. This increasing trend in rail related derailments suggests that there is a need for improved rail maintenance and/or inspection practices to prevent the occurrence of these defects or to find the defects before they cause these expensive derailments. These improvements can take several forms, to include more aggressive rail replacement or maintenance practices or improved rail testing equipment. However, the focus of this article is on a easier to implement approach, one that can be applied almost immediately with a relatively modest impact on a railroad’s maintenance of way budget, specifically the improvement in the scheduling of conventional rail test equipment. As rail accumulates tonnage, it tends to develop more internal fatigue defects, based on various factors such as metallurgy of the rail, traffic (to include such factors as axle loading and speed), track support conditions, etc. This behavior is illustrated in Figure 3. As defects occur more frequently, it becomes important to test more frequently in order to insure that internal defects can be located and replaced before they have the opportunity to propagate to failure, and possibly result in a derailment. Earlier studies have indicated that approximately 1.3 derailments occur per thousand defects (detected plus service), thus highlighting the importance of matching test frequency to the rate of defect occurrence [3]. Simplistic rail test scheduling approaches, such as those based on annual tonnage levels, which do not account for aging rails and corresponding increased defects, do not give the railroad the flexibility to adjust test frequency to the actual rail conditions encountered. Likewise, simplified “rules of thumb” for scheduling ultrasonic testing, while often accounting for such factors as age of rail (usually in cumulative MGT) annual traffic density, class of track, type of traffic, defect counts, etc., do not do so in a manner that is directly tied into the “risk” of a derailment occurring. Rather, it is necessary to have a risk based scheduling methodology which makes use of site specific and directly measurable performance parameters that, in turn, can be related to a defined level of risk. Such a methodology was developed by US Department of Transportation Center Volpe National Transportation Systems Center [4], and further enhanced by ZETA-TECH Associates, Inc. [5].Item Controlling Track Forces during Introduction of New High Speed Trains(International Railway Journal, 2001-10) Zarembski, Allan M.; Palese, J. W.; Bell, J. G.As part of its program to introduce a new generation of high speed trains in the United States, Amtrak, the owner of both the equipment and the infrastructure, defined an objective of minimizing any increase in track maintenance or damage to the track structure or its components. The concrete ties on the Northeast Corridor were a particular source of concern in light of the tie cracking problems that had been experienced by Amtrak in the 1980s. The primary focus of attention was the dynamic wheel/rail impact forces applied to the track structure. Research studies have shown that significant increases in wheel/rail dynamic forces can occur at high speeds with a corresponding potential increase in track degradation, component failure, and track maintenance costs. To avoid this effect, Amtrak introduced a specific requirement for the design of the new high speed Northeast Corridor equipment to maintain the level of dynamic vertical wheel/rail forces applied to the track no higher than current levels. Thus for proposed new electric equipment to be operated at 150 mph, the dynamic impact forces were set at a level corresponding to the existing AEM7 electric locomotive operating at 125 mph. Likewise for the proposed new fossil fuel (diesel) equipment to be operated at 125 mph, the force levels were set to that of the existing F40 diesel locomotive operating at 90 mph.Item Implementation of a Dynamic Rail-Highway Grade Crossing Transition(Transportation Research Board, 1999-01) Zarembski, Allan M.; Palese, J. W.; Katz, LeonidA concern of railroad maintenance engineers is the abrupt change in vertical track stiffness or "modulus" associated with railroad/highway grade crossings. This abrupt change frequently results in increased dynamic wheel loading, increased/accelerated track degradation and poor ride quality. In order to control these increased loading effects and their associated maintenance problems (and costs) the concept of a transition grade crossing design was developed. The intent of this design was to "smooth" the transition from normal track to the stiffer grade crossing structure to minimize the dynamic impact forces associated with the stiffness transition into the crossing. This paper presents the results of an FRA sponsored study of a modified crossing system. The study consisted of an analytical phase, which determined the type of transition required, a design phase which took a conventional concrete crossing design and introduced a series of transition zones, and a testing phase. In the latter phase, a modified PREMIER Concrete Railroad Crossings STEP-PANEL Crossing was manufactured and installed at the Bates Mill Road Crossing of the high-speed NJ Transit Atlantic-City Line, in the vicinity of Atco, NJ. Results of high-speed vertical -dynamics measurements, performed on the Bates Mill Crossing, supported the results of the analytical modeling, and showed that the use of the transition resulted in the elimination of approximately 60 - 70% of the additional dynamic loading at the crossing.Item On the Derailment of Rail Vehicles Through Turnouts: A Review of Derailment Causes and Mechanisms(1996-08) Zarembski, Allan M.; Palese, J. W.; Holfeld, D. R.This paper presents a review of causes and mechanisms associated with the derailment of rail vehicles in turnouts. The paper makes use of several recent studies of derailment causes in both transit and freight rail environments and addresses those factors that contributed to the derailments. This specific area of focus is that of track caused derailments for the several classes of rail vehicles together with remedial actions that can be taken to prevent future occurrences.Item On the Development of Computer Model for the Economic Analysis of Alternate Tie/Fastener Configuration(American Railway Engineering Association, 1991-12) Zarembski, Allan M.; Palese, J. W.; Martens, J. H.The recent trend in rail manufacturing has focused on the development and manufacture of "clean steel", which has been defined as steel with a significantly reduced level of inclusions. This trend has been in response to the increasingly severe loading environment that today's rail is subject to, together with an increasing emphasis on reduction in rail failures (defects), and a corresponding increase in the rail's service life, particularly under conditions where fatigue is the dominant mode of service failure. As a direct result of this, steel manufacturers have been upgrading their steel making process to eliminate inclusions and impurities that could result in rail defects. This trend has been accentuated by recent indications of a relationship between increased rail cleanliness and a reduction in the development of fatigue defects in the rail [1,2]. However, this relationship appears to be quite complex, depending on the definition of rail cleanliness (using such techniques as the ASTM-volume fraction of oxide inclusions or the total length of oxide stringers [3]), the type of inclusions, as well as other metallurgical properties such as rail hardness [2]. However, data showing a direct correlation between changes ("improvements") in manufacturing process, aimed at increasing the level of cleanliness, and reduction in the level of rail fatigue defects in service, has been extremely limited. The purpose of this report is to present two such sets of data relating the in service performance of rail, made by one rail manufacturer, Bethlehem Steel Corporation, to changes in the rail steel making process. These two sets of data represent actual fatigue defect histories on two major u.s. railroads under a broad mix of traffic. The objective of this activity was to analyze the performance and behavior of standard carbon rail and fully heat treated rail produced by Bethlehem Steel Corp. and to define the relationships between performance, specifically development of fatigue defects, and manufacturing process and practice as defined by the time period of rail manufacture.Item Rail Maintenance Planning Using Computerized Rail Forecasting Models(1993-06) Palese, J. W.; Zarembski, Allan M.This paper presents the development and use of rail life forecasting models for rail maintenance planning. This class of rail life forecasting models make use of computerized life prediction models to calculate the replacement life of the rail due to its major failure mechanisms, wear and fatigue. By using these mechanistic dependent failure models to predict the life and thus the replacement point of the rail, it is possible to forecast capital, as well as maintenance, requirements; for both short and long term. Also by knowing where and when the rail must be replaced, it permits more accurate planning and scheduling of the; rail maintenance activities. The use of this type of forecasting model on a North American railway is illustrated together with an example of a specific application.Item Reduction of Dynamic Wheel/Rail Impact Forces at Grade Crossings Using Stiffness Transitions(American Society of Mechanical Engineers, 2001-11) Zarembski, Allan M.; Palese, J. W.; Katz, LeonidThis paper presents the results of combined analytical and field study of the use of vertical stiffness transition zones to reduce dynamic wheel/rail impact forces at the interface between conventional track and high/rail grade crossings. These interfaces are traditionally sites of severe dynamic impact forces and corresponding rapid degradation of the geometry of the track. A recent FRA sponsored research study developed a new analytical technique to define the number of and magnitude of the stiffness transition zones needed to reduce the dynamic impact forces. This technique was used to design a series of transitions for a concrete grade crossing, which were installed on New Jersey Transit's Atlantic City Line in the vicinity of ATCO New Jersey in 1998. Field tests performed on the grade crossing after installation showed a significant reduction in measured dynamic vertical accelerations across the grade crossing as compared to other crossings on the same line. Recent follow up evaluation of this grade crossing showed that it is performing significantly better than similar adjacent grade crossings on the same line and that there has been a marked reduction in degradation of the track/grade crossing and associated maintenance. This paper will present the results of the theoretical formulation. analytical study, and the field tests.