Transactions of the American Society of Civil Engineers, Vol. LXX, Dec. 1910 E-Book

Beverly S. Randolph

• Herausgeber: Science & Technology Publishing
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 26

Veröffentlichungsjahr: 2025

Beschreibung

Transactions of the American Society of Civil Engineers, Vol. LXX, December 1910: Locomotive Performance On Grades Of Various Lengths, Paper No. 1172 is a comprehensive technical treatise that delves into the intricate dynamics of locomotive operation over railway grades of differing lengths and inclines. Authored by E. E. Russell Tratman and presented to the American Society of Civil Engineers, this seminal work meticulously examines the challenges and solutions associated with the performance of steam locomotives when traversing varying gradients, a subject of paramount importance in early 20th-century railway engineering. The paper provides a detailed analysis of the mechanical and operational factors influencing locomotive efficiency, including tractive effort, resistance, speed, and fuel consumption. Through a combination of theoretical calculations, empirical data, and case studies, Tratman explores how grade length and steepness impact the hauling capacity and overall performance of locomotives. The work includes numerous tables, diagrams, and mathematical models that illustrate the relationships between grade characteristics and locomotive output, offering valuable insights for engineers tasked with designing and operating efficient railway systems. In addition to its technical rigor, the paper discusses practical considerations such as the economic implications of grade selection, the importance of proper locomotive selection for specific routes, and the potential for technological advancements to mitigate the challenges posed by steep or extended grades. The author also references contemporary practices and innovations in railway engineering, situating his findings within the broader context of ongoing developments in the field. Locomotive Performance On Grades Of Various Lengths stands as a vital historical document, reflecting the state of railway engineering knowledge in the early 1900s and providing a foundation for subsequent advancements in locomotive design and railway construction. It remains a valuable resource for historians, engineers, and enthusiasts interested in the evolution of railway technology and the practical challenges faced by early civil engineers in the development of efficient and reliable rail transportation networks.

Leseprobe

AMERICAN SOCIETY OF CIVIL ENGINEERS

INSTITUTED 1852

TRANSACTIONS

Paper No. 1172

LOCOMOTIVE PERFORMANCE ON GRADES OF VARIOUS LENGTHS.

By Beverly S. Randolph, M. Am. Soc. C. E.

With Discussion by Messrs. C. D. Purdon, John C. Trautwine, Jr., and Beverly S. Randolph.

In the location of new railways and the improvement of lines already in operation, it is now well recognized that large economies can be effected by the careful study of train resistance due to grades and alignment, distributing this resistance so as to secure a minimum cost of operation with the means available for construction.

While engaged in such studies some years ago, the attention of the writer was attracted by the fact that the usual method of calculating the traction of a locomotive—by assuming from 20 to 25% of the weight on the drivers—was subject to no small modification in practice.

In order to obtain a working basis, for use in relation to this feature, he undertook the collection of data from the practical operation of various roads. Subsequent engagements in an entirely different direction caused this to be laid aside until the present time. The results are given in Table 1, from which it will be seen that the percentage of driver weight utilized in draft is a function of the length as well as the rate of grade encountered in the practical operation of railways.

In this table, performance will be found expressed as the percentage of the weight on the drivers which is utilized in draft. This is calculated on a basis of 6 lb. per ton of train resistance, for dates prior to 1880, this being the amount given by the late A. M. Wellington, M. Am. Soc. C.. E.,[A] and 4.7 lb. per ton for those of 1908-10, as obtained by A. C. Dennis, M. Am. Soc. C. E.,[B] assuming this difference to represent the advance in practice from 1880 to the present time. Most of the data have been obtained from the "Catalogue of the Baldwin Locomotive Works" for 1881, to which have been added some later figures from "Record No. 65" of the same establishment, and also some obtained by the writer directly from the roads concerned. Being taken thus at random, the results may be accepted as fairly representative of American practice.

Attention should be directed to the fact that the performance of the 10-34 E, Consolidation locomotive on the Lehigh Valley Railroad in 1871 is practically equal to that of the latest Mallet compounds on the Great Northern Railway. In other words, in the ratio between the ability to produce steam and the weight on the drivers there has been no change in the last forty years. This would indicate that the figures are not likely to be changed much as long as steam-driven locomotives are in use. What will obtain with the introduction of electric traction is "another story."

These results have also been platted, and are presented in Fig. 1