Overhead Contact System Research Articles

架線・パンタグラフ間の接触力の特徴と電車線診断手法の検討

架線・パンタグラフ間の接触力の特徴と電車線診断手法の検討

210 架線・パンタグラフ間の接触力測定による電車線診断技法の検討

210 架線・パンタグラフ間の接触力測定による電車線診断技法の検討

Dynamics of an Overhead Line and Pantograph System

The dynamic interaction between pantograph and catenary is studied. The overhead electrification system for high speed trains is modelled by visco-elastically connected double homogeneous strings system, one finite suspended on rigid concentrated supports and the second of infinite length. The pantograph is represented by one degree of freedom oscillator moving along the string at a constant speed. The model is new in that it gives possibility to consider the influence of the locomotive transverse vibrations on railway overhead contact system. The dynamic state of the investigated system is described by a nonlinear set of coupled partial differential equations with complicated boundary conditions. Dynamic transverse displacements of the connected strings are determined. General results are illustrated by numerical examples.

On wave solutions in overhead wire dynamics

This paper is concerned with the dynamics of the ‘simple catenary’ type of overhead contact system for current collection on electrified railway lines. First, on certain assumptions, a wave solution is derived for the dynamic response of the overhead system to a time-dependent travelling concentrated load applied direct to the wire. Secondly, a wave solution is derived for a special case of loading through a rigid mass travelling in point contact with the wire. For this case, when the velocity of the mass along the wire exceeds a certain critical value, the solution for the contact force on the wire diverges as the mass approaches and reaches a dropper. This critical velocity phenomenon is discussed in relation to its possible occurrence in more general solutions of the problem of the overhead system loaded through a pantograph.

Numerical Method for Calculating the Dynamic Behaviour of a Trolley Wire Overhead Contact System for Electric Railways

A numerical method is described that has been used for predicting the dynamic behaviour of a trolley wire overhead contact system when disturbed by the pantograph on the train roof. The vertical motion of the trolley wire is given by the solution of a fourth order partial differential equation and that of the pantograph is given by the solution of ordinary differential equations, these two solutions being linked by the conditions holding at the contact point. Results obtained from the method have encouraged British RaU to set up a test line of this equipment to see if a trolley wire can be developed as a cheap alternative to the present more elaborate systems.

Closure to “Discussions of ‘Railway Overhead Contact Systems, Catenary-Pantograph Dynamics for Power Collection at High Speeds’” (1968, ASME J. Eng. Ind., 90, p. 700)

Closure to “Discussions of ‘Railway Overhead Contact Systems, Catenary-Pantograph Dynamics for Power Collection at High Speeds’” (1968, ASME J. Eng. Ind., 90, p. 700)

Railway Overhead Contact Systems, Catenary-Pantograph Dynamics for Power Collection at High Speeds

A program has been prepared for the GE-625 computer in Fortran IV language to compute the dynamic behavior of a catenary and pantograph for railroad cars moving at constant velocity. The catenary is considered to consist of two wires joined by elastic droppers at arbitrary locations. The upper catenary wire is in turn supported by elastic towers at arbitrary locations. Account is taken of: Tension and mass in each wire; wire sag; damping of the wires; springing between shoe and wire; springing and damping between shoe and pantograph frame; damping of the pantograph frame to the railway car; lifting of the wire away from the shoe; and stops in the pantograph to limit motion between shoe and pantograph frame. Up to eight arbitrarily spaced pantographs can be included, with as many as sixty droppers and ten towers. Force at up to ten droppers can be printed as a function of time. The additional output is catenary deflection and forces and deflections of the pantographs. Results are presented for some interesting variations of the system constants.

Railway Overhead Contact Systems: First Paper: An Experimental Study of the Overhead Contact System for Electric Traction at 25 kV

Increasing train speeds and the use of multiple pantographs have emphasized some of the problems of ensuring good current collection from the light overhead contact system used for railway electrification at 25 kV in Britain and overseas. The development, in Britain, of instrumentation and test methods is described, and the problems which arise as a result of ‘hard spots' and resonance effects are referred to. Experimental investigation has shown that greatly improved current collection can be obtained, by suitable modifications, even at speeds exceeding 100 mile/h, and under features such as bridges with minimum clearance. The main principle employed, which has been called ‘stiffness grading’, is to ensure a smooth transition of stiffness, or compliance of the overhead contact system through such features. These are, of necessity, considerably stiffer than normal open route equipment because of the strictly limited electrical clearances. The result is achieved primarily by modifications to the geometry of the equipment. It has been shown that such modifications can reduce appreciably the tendency of the system to build up oscillations of large amplitude, particularly in sequences of spans of approximately equal lengths. This tendency is much more marked where multiple pantographs are used, especially at certain spacings. Such phenomena can be remedied even more effectively by introduction of damping into the system and this can be achieved more conveniently by use of viscous dampers on the pantograph rather than on the overhead contact system. Appendix I describes recent test results which show that modified simple catenary equipment may be suitable for British Railways ‡ requirements if a smooth pantograph trajectory is ensured by suitable control of contact wire profile. This can be achieved by the use of mid-span sag. It will give an appreciable reduction of cost.

The development of and field tests on different types of high-voltage overhead traction equipment

With the increase in the high-voltage overhead-contact system of railway electrification throughout the world in the past 10 years it has become increasingly necessary to investigate in greater detail the problems associated with current collection, particularly with the lighter overhead equipment used in this system and the higher train speeds possible with electrification. These problems have been dealt with in connection with the 25 kV a.c. electrification schemes in British Railways by the design of overhead equipment to meet the particular requirements and also by the development by the London Midland Region of a specially instrumented high-speed test car capable of measuring all the factors influencing current collection.

Overhead Contact Systems for Railway Electrification

Overhead Contact Systems for Railway Electrification

Sleet Problems on Electrified Railroads

Sleet storms, or more properly ice storms, have always presented serious difficulties to the operators of overhead electric conductors of all classes. For more than 25 years some electric-power companies have been using the circulation of electric current to heat the conductors, either to melt off the ice or to prevent it from forming. The technique of such procedure is well-known and will not be dealt with in this paper, other than to present fundamental theoretical data. Electrified railroads operating with overhead contact systems have similar ice storm problems, and, in addition, a number of special problems caused by such ice. These problems are outlined in this paper, and some means which have been used or proposed for their solution are described, Operating experience with one special application to a case of severe exposure to ice storms and high wind velocities is cited. Some of these special railroad problems have not yet been satisfactorily solved.

Sleet problems on electrified railroads

Sleet storms, or more properly ice storms, have always presented serious difficulties to the operators of overhead electric conductors of all classes. For more than 25 years some electric-power companies have been using the circulation of electric current to heat the conductors, either to melt off the ice or to prevent it from forming. The technique of such procedure is well-known and will not be dealt with in this paper, other than to present fundamental theoretical data. Electrified railroads operating with overhead contact systems have similar ice storm problems, and, in addition, a number of special problems caused by such ice. These problems are outlined in this paper, and some means which have been used or proposed for their solution are described. Operating experience with one special application to a case of severe exposure to ice storms and high wind velocities is cited. Some of these special railroad problems have not yet been satisfactorily solved.

Papers on overhead contact systems

H. F. Brown: Mr. Viele's paper emphasizes many points which are in line with similar experience on the New Haven system such as I. The advantage of the auxiliary wire above the working conductor. 2. The necessity for proper steadying devices for the trolley, on both tangent and curve construction, especially against transverse wind loads. 3. The avoidance of long spans in exposed locations. 4. The advantage of locating sectionalizing and splicing devices at or near the supports. 5. The avoidance of hanger members which do not make a positive contact with both the messenger and the contact. 6. The importance of correlating the pantograph design with that of the overhead contact system, and the possibility and desirability of further refinement in the pantograph design.

Abridgment of catenary design for overhead contact systems

THE rational mechanical design of any overhead contact system must be based upon certain fundamental rules of mechanics, usually those dealing with statics, or forces in equilibrium, applied to the physical characteristics of the track alinement. Theoretically a problem for the civil engineer, the general solution and detailed application of the design has been assigned to the electrical engineer in most cases, as the number of papers presented on this subject would indicate.

Abridgment of current collection from an overhead contact: System applied to railroad operation

This paper discusses, from a non-mathematical standpoint, certain factors which should enter into the design of an overhead contact system on an electrified railroad. It emphasizes desirable features, mechanical and structural, and indicates practical limits which conditions will permit in the attainment of these features. Tests made by the Pennsylvania Railroad with slow-motion photography are outlined. These tests were made to determine operating conditions of the catenary construction with two different types of supporting attachments, over both curved and tangent track. Deflections and oscillations were studied in order to bring out the most productive sources for future study and improvement of the design in respect both to elimination of wear and to maintenance of uniformly good current collecting qualities.

Catenary Design for Overhead Contact Systems

This paper is intended to outline methods which have been found useful in the design of overhead contact systems where catenary construction is employed, with especial reference to the single catenary construction installed in 1925 on the Danbury Branch of the New York, New Haven, and Hartford Railroad as an extension of its 11,000-volt, single-phase, a-c. electrified zone; and on the New York, Westchester, and Boston Railway on its extension from Larchmont to Harrison, N. Y. Part I deals with construction over straight or ``tangent'' track, and is a review of methods and formulas which, while not new, are necessary as an introduction to Part II, which not only includes tangent-chord construction, but deals at length with the design of the so-called inclined catenary and its adaptation to curved track.

Current Collection from an Overhead Contact System Applied to Railroad Operation

This paper discusses, from a non-mathematical standpoint, certain factors which should enter into the design of an overhead contact system on an electrified railroad. It emphasizes desirable features, mechanical and structural, and indicates practical limits which conditions will permit in the attainment of these features. Tests made by the Pennsylvania Railroad with slow-motion photography are outlined. These tests were made to determine operating conditions of the catenary construction with two different types of supporting attachments, over both curved and tangent track. Deflections and oscillations were studied in order to bring out the most productive sources for future study and improvement of the design in respect both to elimination of wear and to maintenance of uniformly good current collecting qualities.

Discussion on “unprotected top-contact rail for 600-volt traction system” (Jones), “third rail and trolley' system of the West Jersey and Seashore Railroad” (Duer), “contact system of the Southern Pacific Company, Portland Division” (Lebenbaum), “construction and maintenance costs of overhead contact systems” (Amberg and Zogbaum), “contact system of the Butte, Anaconda and Pacific Railway” (Cox), and “contact conductors and collectors for

Discussion on “unprotected top-contact rail for 600-volt traction system” (Jones), “third rail and trolley' system of the West Jersey and Seashore Railroad” (Duer), “contact system of the Southern Pacific Company, Portland Division” (Lebenbaum), “construction and maintenance costs of overhead contact systems” (Amberg and Zogbaum), “contact system of the Butte, Anaconda and Pacific Railway” (Cox), and “contact conductors and collectors for

Conditions affecting the success of main line electrification

In this paper are laid down the conditions affecting the success, for both the public and the railroad, of a main line electrification project, as they have developed in the author's experience with the New Haven 11,000-volt, 25-cycle, single-phase, overhead contact system. Reliability of service and comfort and cleanliness in operation constitute success from the point of view of the public, while the railroad requires, in addition, economic success. Success is dependent, apart from the engineering, construction, and operating features, entirely upon the density of traffic. A commercially successful electrification is one which cuts the operating expenses of steam-operated territory it has replaced to a figure such that the savings effected are sufficient to justify the investment. The savings in operating expenses made by electrification are, in the order of their importance: saving in fuel; saving in motive-power maintenance and repairs; saving in train-miles. As specimens of the reliable data being obtained from the operation of the New Haven system, statistics from a recent monthly operating report are presented in tables as follows: 1. The amount, distribution and cost of electric power generated at Cos Cob station. 2. Statistics and operating costs of electric passenger service. 3. Statistics and operating costs of electric freight service. 4. Statistics covering line and equipment failures. Tables are also presented showing construction costs for catenary construction of different types, including anchor and sectionalizing bridges.

Overhead Contact Systems, Construction and Costs

This paper, written with special reference to the New Haven electrification, gives a brief analysis of the systems and points to be considered in equipping trunk lines with overhead catenary construction. The paper is subdivided into five parts, viz: catenary systems, supporting structures, sectionalization, special construction and cost data. Under ``Catenary Systems'' a short description is given of the various types used on the New Haven, stating the conditions for which each is best adapted. The same applies to the supporting structures and sectionalization. Under `` Special Construction '' only the cross-overs and river crossings have been considered more fully, while other special work has only been mentioned, as it was not within the scope of this paper to go into the details of construction. With reference to the cost data: It should be borne in mind that the figures given apply to the New Haven construction which was installed in the section with greatest traffic density, also through thickly settled communities. Therefore, the figures given will be of little value for comparison or estimating unless these Conditions are equated.