Dynamic Load Augment From Steam Locomotives

Author(s):  
Gary Fairbanks ◽  
Harold Weisinger ◽  
Steven Zuiderveen ◽  
Anand Prabhakaran ◽  
Tanner Buel

Railroad bridges experience dynamic wheel load augment from rolling stock that cross the bridges, due to nominal bridge and suspension dynamics, as well as anomalies such as wheel flats. The level of dynamic augment is particularly high for steam locomotives due to the hammer blow effect associated with the driven wheels. Tests conducted in the early-mid 20th century had quantified some of these effects, and the resulting findings have been part of the impact formulae presented in the AREMA Railway Engineering Manual. However, there was concern that the impact associated with some of the non-cross counter-balanced, lighter, older locomotives, could be higher than specified by AREMA formulae. This paper describes the methodology and results from a series of tests that evaluated the levels of dynamic augment experienced by railroad track and an exemplar bridge under a set of narrow gauge steam locomotives, and compares the measurements to the design values specified in the AREMA Manual. Vertical and lateral loads on railroad track, and strain levels on multiple critical bridge members were measured under three different classes of light, narrow gauge steam locomotives, over a range of operating speeds and conditions. The tests were conducted on a 120 ft span, through truss bridge, and adjacent track on a tourist railroad. Dynamic augment values measured during the tests were generally lower than the values expected from AREMA formulae. Similarly, the peak lateral loads measured appear to be nominal and lower than the AREMA prescribed values. However, it should be kept in mind that these results are from tests conducted with three relatively light, narrow gauge locomotives, on specific bridge and track, whereas, the AREMA formulae are intended to cover a wider range of conditions. These tests tend to show that the legacy standards are conservative and are applicable to calculating regulatory required bridge loads where steam locomotives are concerned.

2021 ◽  
Vol 3 (3) ◽  
pp. 33-37
Author(s):  
Jairo Aparecido Martins ◽  
Estaner Claro Romão

This paper presents an investigation of changes on design and material of a Howe bridge under vertical loads. Specifically, it aimed to find out how small changes on Howe bridge design and material affected von Mises stresses as well as stresses at Z direction. As a method, it was used a finite element analysis (linear-elastic) by Autodesk F-360. Half of a bridge was designed (one bridge side) and loaded with a central higher load and two equal smaller lateral loads. In essence, von Mises stresses (s) and stress at Z direction (sz) decreased on stresses values until a certain design change, which was proportional to a raise of mass due to beams added on the trusses. With a change of material to a lighter metal, from steel to aluminum, it was possible to overcome the mass drawback brought by steel and utterly possible to end up for a more effective design for a Howe truss bridge by applying minimal design changes.


Author(s):  
Scott Cummings ◽  
Richard Reiff ◽  
John Punwani ◽  
Todd Snyder

Wheel shelling is the cause of a large portion of high impact wheels. The impact loads produced by shelled wheels can have a damaging effect on track components and rolling stock components such as roller bearings. Shelling is the result of accumulated rolling contact fatigue (RCF) on the wheel tread surface. To investigate the specific conditions in which RCF occurs, wheel load environment data was collected from a car with three-piece trucks running in revenue service. This data was analyzed in order to assess the predicted wheel RCF through the use of shakedown theory. An inspection team was dispatched to several track sites to record relevant information including a visual assessment of rail RCF, rail transverse profile, rail age, and friction conditions. Track inspections were conducted at locations where RCF was predicted and at nearby locations with similar curvature where RCF was not predicted. Conclusions from this work are the following: • The curve unbalance condition, which is a combination of curvature, track superelevation, and train speed, is an important factor in RCF. • Wheel/rail coefficient of friction in curves can be a factor in RCF. • Rail profile and track condition were not found to be major factors in this analysis. • Observed rail RCF condition correlated reasonably well with predictions when considering extenuating factors such as rail age and curve unbalance conditions. • Confidence was increased in previous simulation results involving three-piece trucks due to good correlation with the results of the current work. The simulation results suggest that the use of AAR approved M-976 trucks should reduce RCF. This work was funded by the Federal Railroad Administration (FRA) and the Wheel Defect Prevention Research Consortium (WDPRC), a group that includes railroads, private car owners, and industry suppliers.


Author(s):  
Yuriy Boronenko ◽  
Rustam Rahimov ◽  
Waail Mahmod Lafta

Abstract Determine and control the impact of rolling stock on the railway track, one of the significant subjects of railway engineering, especially with heavy traffic and innovative freight cars with increased axle loads. Different methods utilized to measure the lateral impact of rolling stock on a railway based on the use of strain gauges installed on the rail differ in the location of strain gauges and the specifics of processing the received signals. The shortage of these methods that the lateral force arising from the wheel/rail interaction determined when the wheel position over the strain gauges sections. Therefore, continuous registration of details in the wheel/rail contact is impossible. Multiple passes of the test rolling stock along the measuring section are required to receive the right results. In this article, a new method developed to continue recording the lateral forces of the wheel/rail interaction by measuring stresses in two sections of the rail on a significant part of the sleeper space. The railway track experiments approved this method’s ability to restore the lateral force of not more than 4% standard deviation along the measuring zone’s length and increased the volume of reliable statistical data obtained, improved the measurement accuracy, and reduced the time and cost.


2012 ◽  
Vol 43 (1-2) ◽  
pp. 54-63 ◽  
Author(s):  
Baohong Lu ◽  
Huanghe Gu ◽  
Ziyin Xie ◽  
Jiufu Liu ◽  
Lejun Ma ◽  
...  

Stochastic simulation is widely applied for estimating the design flood of various hydrosystems. The design flood at a reservoir site should consider the impact of upstream reservoirs, along with any development of hydropower. This paper investigates and applies a stochastic simulation approach for determining the design flood of a complex cascade of reservoirs in the Longtan watershed, southern China. The magnitude of the design flood when the impact of the upstream reservoirs is considered is less than that without considering them. In particular, the stochastic simulation model takes into account both systematic and historical flood records. As the reliability of the frequency analysis increases with more representative samples, it is desirable to incorporate historical flood records, if available, into the stochastic simulation model. This study shows that the design values from the stochastic simulation method with historical flood records are higher than those without historical flood records. The paper demonstrates the advantages of adopting a stochastic flow simulation approach to address design-flood-related issues for a complex cascade reservoir system.


2021 ◽  
Author(s):  
Mark M. Dekker ◽  
Rolf N. van Lieshout ◽  
Robin C. Ball ◽  
Paul C. Bouman ◽  
Stefan C. Dekker ◽  
...  

AbstractRailway systems occasionally get into a state of being out-of-control, meaning that barely any train is running, even though the required resources (infrastructure, rolling stock and crew) are available. Because of the large number of affected resources and the absence of detailed, timely and accurate information, currently existing disruption management techniques cannot be applied in out-of-control situations. Most of the contemporary approaches assume that there is only one single disruption with a known duration, that all information about the resources is available, and that all stakeholders in the operations act as expected. Another limitation is the lack of knowledge about why and how disruptions accumulate and whether this process can be predicted. To tackle these problems, we develop a multidisciplinary framework combining techniques from complexity science and operations research, aiming at reducing the impact of these situations and—if possible—avoiding them. The key elements of this framework are (i) the generation of early warning signals for out-of-control situations, (ii) isolating a specific region such that delay stops propagating, and (iii) the application of decentralized decision making, more suited for information-sparse out-of-control situations.


2020 ◽  
pp. 442-451
Author(s):  
А.V. Batig ◽  
A. Ya. Kuzyshyn

One of the most important problems that pose a serious threat to the functioning of railways is the problem of freight cars derailment. However, according to statistics, the number of cases of the derailments of freight cars in trains annually grows. Тo prevent such cases, the necessary preventive measures are developed, and to study the causes of their occurrence, a significant number of mathematical models, programs and software systems created by leading domestic and foreign scientists. Studies of such mathematical models by the authors of this work have led to the conclusion that they are not sufficiently detailed to the extent that it is necessary for analyze the reasons of its derailment. At the same time, an analysis of the causes of the rolling stock derailments on the railways of Ukraine over the past five years showed that in about 20 % of cases they are obvious, and in 7 % of cases they are not obvious and implicitly expressed. The study of such cases of rolling stock derailment during an official investigation by the railway and during forensic railway transport expertises requires the use of an improved mathematical model of a freight car, which would allow a quantitative assessment of the impact of its parameters and rail track on the conditions of railway accidents. Therefore, taking into account the main reasons that caused the occurrence of such railroad accidents over the last five years on the railways of Ukraine, the article selected the main directions for improving the mathematical model of a freight car, allowing to cover all the many factors (explicit and hidden) and identify the most significant ones regarding the circumstances of the derailment rolling stock off the track, established on the basis of a computer experiment. It is proposed in the mathematical model of a freight car to take into account the guiding force, the value of which is one of the main indicators of the stability of the rolling stock. The authors of the article noted that not taking into account the influence of the guiding forces on the dynamics of the freight car can lead to an erroneous determination of the reasons for the rolling stock derailment or even to the impossibility of establishing them.


Significance The rail industry is also stressing its green credentials as it seeks approval for a merger between Canadian Pacific and Kansas City Southern that would create the first company with a pan-North American freight line. Impacts The impact of COVID-19 on demand for long-range travel, especially business travel, remains uncertain. Much of Amtrak's rolling stock is at or near the end of its useful service life, pushing up operating costs. Rail and urban transit modernisation would support Biden's aim of creating more jobs in US manufacturing and infrastructure. Replacing highway-funding petrol taxes with vehicle usage fees would encourage freight to move from road to rail.


2020 ◽  
pp. 344-395
Author(s):  
Richard Haw

The Niagara contract was a fitting judgment on John’s career to date, and the bridge itself was a triumph, eliciting praise and admiration from all over the globe, for both its handsome Egyptian architecture and the soundness of its design. It took four years to build and was the world’s first railroad suspension bridge, or at least the first successful one, fully demonstrating the strength and effectiveness of the suspension plan for heavy-going freight. It also compared very favorably with Robert Stephenson’s recently completed Britannia Tubular Bridge, the British engineer’s rival solution to the problem of long-span railroad bridges. A lifelong, committed abolitionist who wrote extensively about the evils of slavery, John also appreciated the impact his bridge had (somewhat incidentally) on the institution of slavery. Harriet Tubman (among others) used John’s bridge numerous times in the late 1850s to lead runaway slaves out of the United States and into British Canada.


2018 ◽  
Vol 239 ◽  
pp. 03005
Author(s):  
Lidia Shkurina ◽  
Eugenia Maskaeva ◽  
Stanislav Maskaev

the authors reviewed the quality of operational work of railway transport in the cost management system, presented methods for assessing the impact of the quality of rolling stock on the current costs of transportation activities, considered the issues of the impact of the quality of operational work on the formation of freight market demand and of financial result of the transport company - the owner of infrastructure and traction rolling stock, represented methods of assessing financial and economic efficiency of improving the quality of operational work for the company - a participant of the freight market.


Author(s):  
Wolfgang Fricke ◽  
Bjarne Gerlach ◽  
Matthias Guiard

Aboard ships windows are exposed to static as well as dynamic loads, e.g. impact loads. Failure can lead to serious consequences. Therefore two research projects were initiated in order to analyze the load carrying behavior of windows. In addition to quasi-static ultimate load tests and drop tests with water filled rubber bags special attention is paid to the Finite Element (FE) modeling. In particular the response — stresses and deformations — to quasi-static lateral loads can be calculated with good agreement to test results. Hence FE calculations can be useful to determine and compare failure mechanisms of different window designs. An ultimate load range can be estimated by taking into account the breaking strength range of glass. A comparison between FE calculations and results of the impact tests showed that these are sensitive to conditions which could hardly be measured during the test, e.g. the shape of the approaching water-filled rubber bag. Varying of parameters eventually yielded that window response to impact loads can also be calculated sufficiently, at least, to evaluate different window designs. Further investigations on this topic are in progress.


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