Transactions of the American Society of Civil Engineers

The paper first describes all the methods which have been proposed for the complete analysis of secondary stresses due to the rigidity of the joints in bridge trusses. Approximate methods, however, such as those of Engesser and Landsberg, which neglect the effect of the web system, are not included.

A typical through railway bridge of six panels is analyzed by each method in turn, using unsymmetrical loading, in order to test more thoroughly the advantages and disadvantages of each method. A critical comparison is then made of the methods thus applied.

Influence lines are developed for the secondary stresses in all the members of the main trusses, in the top chords as effected by the top lateral system, and in a typical cross-frame. These influence lines are then combined for the purpose of computing the maximum secondary stresses in certain typical members.

During 1924 larger quantities of petroleum and petroleum products have been in sto rage in the United States than ever before. Considering the quantity of this oil in storage and its generally inflammable nature, the fire loss has been remarkably low.

Refined oils (which comprise by far the largest part of oil storage in or near cities and towns), when ignited, simply burn quietly until they are extinguished or burned dry; but crude petroleums, and occasionally refined fuel oils, are liable to boil over while burning. In order to make the storage of these latter products as safe as that of the refined oils, it is necessary to surround the container with so-called fire-walls.

The service to be rendered by these structures is a peculiar one from an hydraulic standpoint, as their primary functio;n is to withstand the single wave of oil thrown out by the “apos;boil-over”. In an effort to find the best possible design, the series of model tests here described was conducted, the outstanding result being a demonstration of the value of some form of flash-board or coping which will curl the advancing wave back on itself.

The purpose of this paper is to discuss the amount of future traffic upon American highways and to compare this with the traffic capacity of a two-lane road.

In order to do this, it is necessary to project what the progress is to be in the future, and this is always fraught with many uncertainties. Even if the physical facts on which to base a prediction are known, social forces may not continue to act as in the past, and thus new conditions arise that affect vitally the results. If the facts are known, and the forces, both social and economic, do not sensibly change, then one may predict with considerable assurance what the future may be expected to bring forth.

The physical facts upon which highway traffic rests are the number of vehicles using the road in a given time, the road mileage made by these vehicles during some definite period, and the mileage of the system of highways upon which the traffic moves. If, through a considerable period of time, these quantities have persisted at concordant rates, then future values may be predicted. In the instance of highway use, the values thus found will be approximately true, provided the causes that create a desire for the use of the motor vehicle do not change. For the present purpose, it is assumed that such will be the case; that people will not tire of the motor vehicle as a form of recreation; that, due to further congestion, increased traffic will not become the means that will strangle itself. All that is favorable to the continuance of travel by highway is to be assumed. With these conditions imposed, it is useful to endeavor to see what the future holds in store for the highways.

This paper reports investigations conducted by the Engineering Experiment Station of Purdue University in co-operation with the U. S. Bureau of Public Roads, and reviews the literature on the measurement of volume changes in Portland cements and concretes.

The primary purpose of the investigations was to m easure the maximum warping and surface deformatio ns produced in a concrete road slab as a result of a non-uniform distribut ion of moisture, to give a basis for estimating possible initial stresses. The tests also yield data of expansion and contraction of concrete, useful in the design of concrete structures.

When the wise king of the Hebrews sought to express the fundamental unity of the problems which confront each human life he began with the atmosphere. “When I was born”, he says, “I drew in the common air, and fell upon the earth, which is of like nature, and the first voice which I uttered was crying, as all others do.” “The common air” is indeed the basic condition of human existence, controlling it in more ways than are yet fully realized. The atmosphere in its relations to human health and comfort seems, therefore, a topic peculiarly appropriate for consideration by a group of men whose objective is the application of the principles of engineering science in the special field of sanitation.

The problem of safeguarding health and preserving the comfortable enjoyment of property is becoming increasingly complex. While remedies grow more efficient, standards mount higher and new dangers are added by commercial and industrial development and the steady influx of population from rural districts to urban centers. The topic under consideration concerns the contamination of the air. Possibly no single natural right is more closely related to the preservation of health, the enjoyment of life, and the comfortable occupation of property than the privilege to breathe clear, pure, and wholesome air.

During 1920-21 the writer was commissioned to make an investigation of an alleged nuisance caused by certain oil refining plants in the Metropolitan District of Providence, R. I. In planning this investigation it had to be borne in mind that although it was desirable to obtain as full and complete information as possible on all correlated points, only a very limited appropriation was. available for the purpose. Before starting the investigation, therefore, a search was made through health and sanitary journals and reports to asce rtain what methods had been followed in other investigations of similar import.

The disposal of garbage is an operation in which an odor hazard must be fairly recognized. Unless garbage disposal works are designed, built, and operated with care, odors may result. In fact, with some methods of disposal, odors are likely to result unless the design and operation are good. In this regard, garbage disposal is somewhat akin to the odor-producing industries such as tanneries, packing houses, glue works, oil refineries, rendering plants, etc. Measures for odor elimination thus become pertinent. A number of factors influence the general problem of the elimination of odors from garbage disposal works, one of which centers about the environment.

A study of this subject presupposes a knowledge of the general subject of odors, their nature, production, and means of transport. The writer has had no opportunity for experimental work and, therefore, can treat the subject only in the most general manner. A line of research, however, is suggested which may produce results.

The subject has been studied under the following heads:

Character of Odors,

Source of Odors,

Control of the Production of Odors.

Control of the Escape of Odors,

Conclusions.

In a commercial or practical sense, the word, petroleum, applies to natural, liquid hydro-carbons which, from a scientific standpoint, are not strictly liquid, but are mixtures of gases, liquids, and colloidally suspended solids. Shortly after its discovery, the chief use of petroleum was in the preparation of illuminating oil. Following this occurred the development of petroleum lubricants which were found to be superior to the animal and vegetable fats and oils previously used. However, it is chiefly because of the development of the internal combustion engine and the increased use of oil as fuel that the petroleum industry has become so extensive.

The writer assumes the only substantial justification for a deep waterway connecting the Great Lakes with the salt seas is the deep penetration of the continent to Duluth, Port Arthur, and Chicago. The navigable right of way of the whole Great Lakes System, therefore, is involved in the discussion. The 1924 project-drafts in Lakes Erie, Michigan-Huron, and Superior with the connecting rivers, are 20 ft. The waterway to the sea contemplates initially 25-ft. and ultimately 30-ft. drafts. The St. Lawrence River is the geological avenue to the sea through which outflow the surplus waters of the Great Lakes.

The water supply of the City of Atlanta, Ga., is of interest from several angles, as it is the largest development of a surface water supply in the Southeastern States, furnishes a water unusually free of dissolved solids and, therefore, peculiarly well suited for industrial uses, and contains, in addition, some unique features of design and operation. The supply is derived from the Chattahoochee River, a Cherokee Indian name meaning the “Chatter”, or ”Hooting of the Owl”. Its source is on the eastern slopes of the Blue Ridge Mountains, at elevations ranging from 3 000 to 4 000 ft., and it flows in a southwesterly direction, through a basin singularly free of pollution.

Among the many things of interest seen and heard at the, World Power Conference (London, 1924), none perhaps was more striking than the variety of methods proposed and tried for the solution of the important problem of high specific speed turbines. From talks with experimenters and visits to European testing laboratories, from the papers on these laboratories and their work presented to the Conference, and from current literature in many languages, the speaker believes that although the subject is not new and is well known in America, yet the many excellent examples of good design and construction at present under way in Europe should be better known to members.

To any one who has followed hydraulic power engineering it must seem surprising that a machine so highly developed as was the hydraulic turbine ten or fifteen years ago, should have suddenly entered a period of radical changes and encountered transformations in many of its essentials. The fact remains, however, that although practice in turbine design had become almost standardized in the period just prior to the World War, the development of this art has taken on new life and has already been revolutionized in many aspects.

This paper is intended to outline in a general way the experience to date with the high-speed, axial-flow type of hydraulic turbine runner for low heads. A brief comment as to the origin of this type is given, together with a statement as to the number of installations, total horse-power involved, etc. Comment is given as to the operating features that have been observed, the heads to which this type has been applied, and the present commercial range of its application.

The writer will indicate briefly the comparative efficiencies which can be obtained by using medium-speed wheels (of which the specific speed, N_s, is equal to about 75) and high-spee d wheels (N_s equal to about 175). The efficiencies shown throughout this paper are based on model runners of the size usually tested at the Holyoke flume, that is, about 39 sec-ft. discharge at 1-ft. head. Under good conditions, it is possible to obtain better results with larger wheels in place. The data and information contained herein are obtained from tests made in the Holyoke flume and in the specially designed and constructed testing flume of the S. Morgan Smith Company.

The records of the United States Patent Office for the last fifty years will show that parallel to the cases of the Francis and Pelton wheels, pioneer work was done in America on water turbines of the propeller type. However, as the commercial demand during that period was for comparatively slow-speed machines, the propeller turbine was apparently neglected in favor of the so-called Francis type for use under low heads. The writer has no record of early European inventions of turbines of the propeller type. Reference may be made, however, to the old Journal type turbine which was occasionally built with rimless runners, with the blades strongly bent, or curved, to suit the slow speed for which such turbines were designed.

In a paper delivered before the American Society of Civil Engineers on October 4, 1922, the writer indicated certain tendencies in water power development, the more important of which were developments in storage and interconnection and a tendency toward increase in the size of units. Increased interconnection has accomplished two important results: First, by broadening the market, it has made it possible to consider the distribution in the general market of the output of the large continuous powers of boundary streams; and, second, it has permitted the selective development for peak purposes of plants on interior streams, by removing the need for flexibility in any individual plant.

To judge correctly of the qualifications of a man for the position of “Railroad Executive”, a comprehensive survey of the duties devolving on the chief executive officer of a railroad under present-day conditions and of the difficulties which he has to overcome, must be made. Not only must the problems that require solution be considered but the limitations imposed by law on the revenues of railroads and the extent of control of their expenses that the executive is permitted to exercise. It seems appropriate, therefore, to introduce a quite full outline of the problems that confront the responsible managing officer, to show the extent to which so far he has solved them, and to what extent they remain unsolved, and then to show how the engineer has risen to new responsibilities, and what recognition stockholders and directors of railroads have accorded to his fitness to administer their properties.

This paper is submitted for the purpose of calling the attention of engineers to the necessity of giving serious consideration to the action of frost when designing dams for use in cold climates. The writers believe deterioration from frost action will occur in any thin concrete structure subjected to water pressure and extreme cold unless the concrete can be made 100% water-proof (or water-tight).

The results of frost action, therefore, have been pointed out in this paper, together with the expensive repairs necessary to safeguard the structure, and it is hoped the discussion will develop some positive and permanent method of water-proofing concrete.

Excess condemnation is the technical remedy for a legal technicality, and being the outgrowth of bad logic, is difficult to explain clearly. It has been defined as the taking by eminent domain (and, therefore, without the consent of the owner) of more land than is needed for a public improvement. The practical man realizes that the development of the land outside the lines of the given improvement, so as to harmonize with the improvement within them, is essential to the attainment of the maximum usefulness of that improvement. In short, he knows that the outside land–not in fact “excess”–is needed for the improvement. This, the judges in the United States, apparently have not been able to realize.

Cities have always found it necessary to open, widen, and extend streets. During the last few years, since the development of city planning, there has been more of this activity than formerly. When these openings, widenings, and extensions are made in developed parts of cities, irregular pieces are often left and the cost of the part taken may be as great as that for the whole lot; the claim being sustained that “the damage to the part remaining equals the value of the whole property.” Sometimes the parts of lots left are not sufficient to insure a proper development.

Excess condemnation! It sounds harsh and gives the feeling that it conveys no promise of benevolence. By definition it is “The lawful power, by the exercise of the right of Eminent Domain, to obtain land in a greater area than that physically necessary for a purposed public improvement, although incidental to it.” The writer will discuss several reasons why excess condemnation is most necessary in present-day building of cities, and also the extent to which it should be carried, and the results of its proper use.

The story of excess condemnation in Massachusetts, as in most States, is a story of small accomplishment so far as the actual exercise of this power is concerned. In certain directions, however, Massachusetts has been a pioneer in formulating principles and establishing the right to use excess condemnation. The Massachusetts Remnant Act of 1904 was the first legislation passed by any State applying the principles of excess condemnation to the taking of remnants of lots of which only portions are actually required for purposes of street improvements.

The device herein described is a promising structure for measuring the rate of flow of either small or large quantities of water. It has no moving parts, and is simple and inexpensive. It utilizes the principle of an hydraulic control and sacrifices little head. Tests indicate an accuracy of about 5 per cent.

The design of a side channel spillway involves certain special hydraulic and economic factors which, it is thought, have not been previously discussed. On account of the disturbed conditions of flow, there are large internal frictional losses, the relative amounts of which are largely dependent on the magnitude and form of the individual installations. Flow can be computed by Bernoulli's theorem, using an experimentally determined coefficient of loss, similar to that of friction in ordinary flow, but such a coefficient would not be constant, and would need to be determined separately for many different sets of conditions. This situation can be avoided by utilizing the law of conservation of linear momentum for determining the flow. Formulas required for this purpose are developed.

The use of relative high velocities reduces the cost of canal per unit length. The limit of velocities permissible is somewhat less than velocities that will erode a canal bed. The determination of permissible velocities is not possible from data on transporting velocities or mere non-silting. velocities. The presence or absence of colloidal matter is of prime. importance. The opinions of irrigation engineers as determined from their experience are given, as well as deductions from available data and the final recommendations of the Special Committee on Irrigation Hydraulics.

The characteristics of flood flow that may have either general or special application and therefore must be considered in any preliminary studies for protecting a given locality are briefly stated, not by way of defining probable flood limits for individual cases, but of indicating methods of deduction that must be followed. The available data that seemed reliable and valuable have been listed and platted to give a visual representation of the range of discharge per square mile for maximum recorded floods. Where possible, the portion of the maximum flow which represents the average annual maximum flood on each stream, has been indicated.

The Ohio River extends from the confluence of the Allegheny and the Monongahela Rivers at Pittsburgh, Pa., to the Mississippi River at Cairo, Ill., a distance of 968 miles. Its width varies from less than 900 ft. to nearly 6 000 ft. and its slope from 11½ in. per mile in the lipper Teach, to 3 in. per mile near the mouth. The more or less uniformly changing slope has one break at the Falls of the Ohio (Louisville, Ky.), where there is a low-water drop of 26 ft. in a distance of 2 miles.

The proper utilization of the Ohio-Mississippi Waterways for transportation is rapidly becoming essential to the safeguarding of National prosperity and to the proper economic and industrial development of the United States. This is considered to be a fair statement because two distinct types of studies have indicated that these waterways afford a means of solving important industrial problems. This particular paper is confined to a description of these two fundamental studies and the relation of the Ohio-Mississippi route to them. The first was a war-time study of production which is equally applicable to the general problem of production, and it stresses a serious situation which is worthy of frequent re-statement from all angles.

The relation of the Ohio River and its tributaries to transportation in the United States may mean either of two things: First, how the one compares with the other as to amount, importance, expedition of service, economy, or some other characteristic; and, second, how the two are connected with or related to each other-the nature and extent of their interdependence and interaction. The first is largely a matter of statistics. The salient facts in regard to transportation on the Ohio River are contained in Tables 10 and 11.

What is the meaning of a river-rail terminal? First, it means that the river will help the, railroads; second, it means that the railroads will help the river; and, finally, that both will help the port as well as the so-called hinterland. Ever city of prominence and importance has been made in two–ways either by water, such as lakes and seaports, or by railroad. The largest cities in the United States, and those of the greatest importance, have a combination of both water and rail.

This paper describes a unique type of dam of consider able size designed by the writer in 1911 and built by the Hackensack Water Company in 1920-22. The unusual design was the outgrowth of an attempt to plan a dam to meet special conditions found at a particular site. It was not intended to develop a type of dam which would be applicable to conditions likely to be found frequently, nor is it suggested that the type described offers a more economical substitute for the usual types of dam under ordinary conditions.

This paper gives the results of a study to determine the fundamental facts on which the utilizable capacity of steel members of structures depends, and to devise methods whereby the utilizable capacity of any member can be determined, as nearly as practicable. The utilizable capacity of any steel member is measured, as the case may be, by the greatest load which statically or repeatedly, or by the greatest opposite lo ads which, alternately, can be applied during the lifetime of the structure (as determined by other considerations) without causing failure, ruin, or seriously objectionable deformation (plastic, elastic, or combined plastic and elastic).

This paper records the results of experiments conducted by the writer to learn what relation the shape of a pavement slab has on its strength. Although these experiments were made in a laboratory with miniature specimens, the condition of moment, stress, and manner of loading was such that the results may be assumed to be representative of the behavior of pavement slabs in actual use. The uniform behavior of the test specimens lends weight to this assumption. With the record of these experiments, a study of moments, as developed in various shaped slabs, is reported.

In March, 1901, Congress provided for the erection of a laboratory by the United States Public Health Service, “for the investigation of infectious and contagious disea ses and matters pertaining to the public health,” and in the same year a Division of Scientific Research was organized in the Bureau of the Public Health Service. Therefore, the year 1901 may be said to mark the establishment of systematic and continued scientific investigation as a recognized function of the Public Health Service. Considering the role which sewage-polluted drinking water was playing at that time in the spread of typhoid fever and other infectious diseases, and recalling that the membership of the Hygienic Laboratory Advisory Board included the great leader in sanitary science, Professor William T.

The biochemical oxygen demand test to be discussed in this paper, although at present it enjoys a certain measure of renewed interest, is by no means new. The earliest record of such a procedure is probably to be found in a report published in 1870 by a British Rivers Pollution Commission. In France, oxygen demand determinations were made as long ago as 1885 in a study of the pollution of the Seine. In Germany, extensive series of experiments were conducted on the test from 1900 to 1911. In the United States, a modified procedure appears to have been used in the early experiments at the Lawrence Experiment Station, although it is only since 1915 that the method now in use has been more or less generally adopted.

In all problems of stream sanitation involving the maintenance of an adequate reserve supply of dissolved oxygen for the preservation of fish life or the prevention of nuisance, there are two major factors to be considered as determining the limiting degree of pollution of streams which is consistent with satisfying a given reserve oxygen requirement. One of these factors is the rate of biochemical deoxygenation of the stream water, proceeding in accordance with laws which have been described by Mr. Theriault.

The U. S. Public Health Service has been engaged for some years in studies of various phenomena concerned with the pollution and natural purification of streams. One general purpose of these studies has been to evaluate the intensity of bacterial pollution to be expected from known populations discharging sewage into streams of known discharge and velocity of flow. With this end in view detailed bacteriological data have been collected from two streams of quite different types, the Ohio and Illinois Rivers. Published observations on the Ohio River covered a period of three years, and those of the Illinois River were continued for a complete year, so that in each instance information was obtained throughout an entire seasonal cycle.

The object of this paper is to apply the principles of Mechanics to the subject of shear in compression members. A method is presented by which given conditions can be analyzed and those which produce the greatest shear can be determined, thus enabling the engineer to design for the most dangerous conditions that he considers it advisable to assume. The relationship between shear and the slope of the column axis herein given has already been published elsewhere, but as far as the writer is aware, the interesting possibilities of this relationship have not previously been developed.

Irrigation and power are both of great importance in the development of the Western States. Both interests require regulation of stream flow, but to different degrees, which may bring them into conflict. This paper gives a general presentation of the factors entering into the problem, illustrates the difficulties, and points out certain solutions by describing some of the specific cases that have come before the Federal Power Commission.

This Committee was authorized in August, 1923, and held its fir st meeting in October of that year. At this meeting, it was unanimously agreed that the first work of the Committee should be to make a thorough study of all existing data before undertaking any further tests. It was thought that it would doubtless be desirable to do further experimental work, but plans for any such work should be based on a careful study of all existing data. In order to carry out this prog ram, it was obviously n ecessary to employ considerable assistance, and it was therefore arranged that M. 0. Withey, Professor of Mechanics at the University of Wisconsin, should devote a large part of his time, during the year 1924-25, in assisting the Committee in this work.