Very early trials with semaphores and other signals failed of acceptance. Starting in 1851 the railroads adopted the still-new electric telegraph, which for the first time permitted a dispatcher at a central point to keep in touch with train crews via telegraph operators at stations along the line. By this means he could issue orders to crews to stop, move or meet other trains as the situation changed. Gradually semaphore and color indication lamp signals came to be introduced at operator's stations so that they could order a train to halt for orders.

Meanwhile, in Europe there had developed a system by which employees at successive block stations along the route, in direct communication with adjoining stations by electric bell or telegraph circuit, could pass trains safely block by block, forbidding entry to eash until it was known to be clear. On the busier railroads of the United States, starting in 1865, this "manual block" system was introduced to provide the increased flexibility of local, but positive, control. Under manual block, the engine man proceeded by obeying signal indications, which supplemented, or superseded, his train orders and timetable rights.

In 1871, development of the closed electric track circuit and electrically or air-operated wayside signals permitted the introduction of automatic block signals actuated by the trains themselves. Since they were not controlled, these signals could not be used to give a right to a train to move but they served to increase safety and movement by indicating the condition of the line ahead. Where movement by signal indication was desired, manual block stations were retained.

Since World War I, automatic block signals have been converted gradually to all light color or position indication, for day as well as night service, and need for semaphores obviated. With increasing length and speed of freight trains, the number of signal indications has been increased for greater refinement in control of stopping, yet without impairing line capacity.

2. Interlocking

As traffic increased and the track network at important junctions and terminals increased in complexity, it became necessary to manipulate track switches from a central point to provide special signals which would indicate to the engineman whether his route was open and at what speed he should take it, and to interlock the two systems so that no conflicting route paths could be established. Thus there came into being, shortly after the Civil War, interlocking plant operated from a "tower." At first, switches were thrown and signals moved by long rods or wires, and the interlocking accomplished by sliding contact bars within the control machine which locked a signal or switch if its movement created a conflict. Starting about 1890, electric or compressed air motors moved switches and signals, and then control from the tower and interlocking of routes was accomplished electrically. Track circuiting permitted the normal automatic block signal feature to be superimposed on the interlocking plant territory. It also prevented switches being thrown under trains.

The chief development in interlocking plans since the 1930's has been routeinterlocking, by which the plant operator merely identifies the locations at which each train will enter and leave the plant territory. The between route is established and accomplished automatically.

3. Centralized traffic control

With the development of coded electrical impulses which could be transmitted long distances, the railroads found they could combine the best features of (a) automatic block signals, (b) movement of trains by signal indication under manual block, and (c) central control of switches and signals accomplished hitherto within limited interlocking areas. In effect they stretched out interlocking plants to cover an entire stretch of line. Installed first in 1927, on a short stretch of single track, centralized traffic control, or “CTC," permits a dispatcher to activate switches and signals over an entire division or more. The signals provide both automatic block protection and give directions to the engineman. Junction and terminal interlocking areas can be tied in as normal parts of the CTC. train crews move in obedience to signal indications, train orders are unnecessary and wayside order points can be discontinued.

Since

Until recent years, CTC was used largely to provide greater capacity for singletrack lines by permitting faster and more flexible "meets" between trains. Today the greater emphasis is on using CTC to permit the reduction of existing doubletrack lines to single, or to remove some of the tracks of three and four track routes, with large savings in track maintenance and property taxes.

4. Automatic train control

Of limited application, except on ultra-high-density passenger routes, are systems of reproducing in the cab the indications of wayside block and interlocking signals. Earlier versions simply repeated indications of individual signals as they passed. Today cab signals utilize continuous track circuits and reflect changes in line condition immediately. In a few instances, the line signals themselves have been eliminated.

Tied in with cab signals, but perhaps even more limited in application today, are systems generally described under the term "automated train control," by which the train is stopped automatically if the engineman fails to obey a signal. Starting in the 1880's many scores of ideas were tried, most of them utilizing a mechanical means of activating brakes from a mechanism located near the relevant signal. A refined form of the mechanical tripper is still in wide use on urban rapid transit lines, but was never adopted successfully on trunkline railroads.

In the early 1920's the Interstate Commerce Commission required the railroads to install, on selected test portions of their routes, various forms of ATC then under development. Some of these the intermittent type-contact the moving train only at the location of the wayside signal. Others provide continuous contact through track circuiting. Almost all types ultimately adopted means by which the engineman could forestall automatic braking action by acknowledging a warning signal given by the ATC system.

In recent years there has been added to ATC so-called speed control which requires the engineman to take precautionary action when he exceeds safe speeds prescribed for a given section of line.

ATC is applied to only a minority of main line routes and, except for ultraheavy passenger density lines, is not now being installed. In fact, a substantial number of railroads have sought permission to remove installations stemming from Interstate Commerce Commission orders of the 1920's on the ground that train frequency has greatly declined.

However, true automation is being developed for railroad operation by at least two supply companies. Presumably, it would provide train movement and speed control without necessity for crews. So far application has been confined to a few industrial situations, mining, and the British Post Office.

5. Communications

Shortwave radio is being applied widely in the rail industry for communications between crews in yards, between the front and rear of freight trains and between fixed stations and trains. Thus far union agreements have prevented full exploitation of radio for giving instructions to crews.

As a substitute for line wire telephone and telegraph communications between offices and stations, there has been installed a substantial network of microwave relays.

D. Performance capabilities with the present state of the art in railroading

The question is frequently asked, "What kind of performance can we get on railroads with the present technology?" This means speed to most people. In 1893, a New York Central locomotive with four cars hit 112.5 mph over a measured mile near Batavia, N.Y. In 1905, a Pennsylvania train ran 3 miles at the rate of 127 miles per hour. By 1915, speeds in excess of 100 miles per hour were being attained over favorable sections of tangent tracks in regular passenger service on a number of railroads. Greater speeds were subsequently achieved in experimental runs in this country and in Europe with the record of slightly more than 200 miles per hour being achieved by a specially geared electric locomotive pulling four specially prepared cars on a section of track in France in 1956. But average speeds for crack trains still run in the range of 60 to 80 miles per hour. At the present time the new Tokaido line is running on schedule with maximum speeds of 125 m.p.h. Naturally, the track, roadbed, and alinement can limit the maximum speed as much as can train performance.

PRESENT FUNDING OF RESEARCH AND DEVELOPMENT IN GROUND TRANSPORTATION

Technological progress in rail transportation has been evolutionary in recent decades. Furthermore, attempts to develop other means of ground transportation with service characteristics similar to rail have, until very recently, been limited largely to basement inventors. Technological progress in other modes especially air has proceeded much more rapidly. Air transportation has benefited from sizable R. & D. programs, while in contrast ground transportation has been characterized by small R. & D. programs. Unlike air transportation which has benefited from large defense and other Federal Government expenditures, ground

transportation has had no Federal Government support directly or indirectly until the start of the HHFA grant program. (This program is still very small compared to the size of the Federal Government support of R. & D. in air transportation.)

Comparisons are seen clearly in table 1 where expenditures as a percent of sales are shown. Company financed R. & D. efforts in rail transportation, by both carriers and suppliers, are modest by comparison with company financed efforts in other industries. The figure of 1.76 percent which R. & D. bears to sales in rail transportation is below the average of all manufacturing industries for which industry and Government R. & D. efforts total 4.40 percent of sales. The total of highway, motor vehicle and other transportation equipment R. & D. expenditure also does not equal the average of all manufacturing (2.48 percent). However, the aircraft industry is well above the all manufacturing average at 24.20 percent.

Relative R. & D. efforts are also reflected in the numbers of scientists and engineers engaged in the different industries as shown in table 3. The most striking comparison is the 101 for air versus the 16 for motor vehicles and other transportation equipment (where motor vehicles raise the average significantly). R. & D. efforts in transportation_supported by all agencies in the Federal Government are shown in table 4. Table 4 shows the HHFA expenditures for rail. (Table 1 does not include urban transit in rail.)

TABLE 1.-Comparison of R. & D. expenditures for various sectors of transport industry

1. R. & D. expenditures as percent of gross railway operating revenues for carriers, and as a percent of sales for suppliers: Science and Technology in the Railroad Industry, National Academy of SciencesNational Research Council, Washington, D.C. (Average for 1960-62.)

2. Research expenditures as a percent of direct expenditures for the entire highway program in 1958: Special Rept. 55; Highway Research in the United States, 1960, Highway Research Board.

3. National Science Foundation, Research and Development in Industry, 1961. Tables A-22, A-24, pp. 84, 86. 1961 figures. Data on company-financed research and development do not include funds contributed by industrial firms for the support of various types of organizations who perform research.

TABLE 2.-Company-financed R. & D. in transportation industries 1

I. Suppliers: Total_

A. Motor vehicles and other transportation equipment 2.
1. Motor vehicles.

3. Railroad equipment 4

2. Ship and boat building

B. Aircraft and parts

II. Carriers: Total 6.

Millions

$1, 007 628

2 National Science Foundation, Research and Development in Industry, 1961, table A-8, p. 69. 3 Not available.

15

379

(7)

6. 2

(3)

4 National Academy of Science-National Research Council, Science and Technology in the Railroad Industry, p. 48.

5 NSF, op. cit. Estimated from NSF 1961 figures. Since 1960 the standard industrial classification used for NSF reporting has been changed to include missiles (SIC 19) with aircraft and parts (SIC 372) straight extrapolation of previous data gives 379 as the estimated portion of $392 million total to be assigned to aircraft and parts alone.

6 NSF, op. cit. The survey gives only the total R. & D. figure for 11 different nonmanufacturing (transportation and nontransportation) industries as $65 million in 1961. Transportation carriers and services comprise 10 percent of that group.

7 Less than 65.

8 NAS-NRC, op. cit.

TABLE 3.-Full-time equivalent number of R. & D. scientists and engineers, by industry, January 1962

Source: Hearings before subcommittee of the Select Committee on Small Business, U.S. Senate, June 5 and 6, 1963. Statement of Dr. Jacob Perlman, National Science Foundation.

TABLE 4.-Transportation R. & D. expenditures applicable to civilian sector by Federal agencies by mode, fiscal year 1963

Source: Survey for Office of the Assistant Secretary of Commerce for Science and Technology.

CURRENT R. & D. IN UNCONVENTIONAL GROUND TRANSPORTATION

Work which has been done or is now going on in research and development of ground transportation systems other than conventional rail ranges from improved applications of wheels on rails to air supported vehicles based on aeronautical engineering.

A concept using steel wheels on steel rails has been proposed by General American Transportation Corp. This system is essentially an auto ferry using tracks and cars wide enough to load automobiles crossways for rapid loading and unloading, and traveling at speeds up to 150 m.p.h. The intent is to relieve the driver of the control of the vehicle, to achieve high speeds, and to allow the traveler to have his own automobile at destination.

Monorails have been attracting interest for many years and still are receiving a considerable amount of attention. The aesthetic cost of elevated monorails has been a deterrent and there are technical problems remaining to be solved before speeds in the range of 100-200 m.p.h. can be achieved.

Many engineers believe that wheels on rails cannot be used for speeds beyond 200 m.p.h. and have turned to air or magnetically supported vehicles. In fact, Prof. Robert Goddard proposed a magnetically supported vehicle in a tube as a student in 1904. Recently the Westinghouse Electric Corp. has been experimenting with magnetically supported platforms, but the instability is so great no further work is being planned.

Air supported vehicles have appeared in many forms ranging from the ground effects machines which "fly" a foot or so off the ground to air bearing vehicles which operate with a few thousandths of an inch clearance above a guideway. Ground effects machines (GEM's) have been studied extensively in this country and Great Britain for both military and civilian applications. The difficulty of control, dust, noise and the relatively low current speeds of such vehicles make them seem unattractive for intercity transportation.

The Ford Motor Co. has an air bearing vehicle called Levacar. Its support is by means of perforated plate through which compressed air flows to float the plate a fraction of an inch above a guiding surface. The major drawback of such a concept is the necessity for an accurately alined guide surface which is expensive to construct and maintain. The power required to propel such a vehicle at high speeds is quite low compared to wheels on rails.

The General Motors Corp. has designed an air supported vehicle named Hovair which uses a flexible plastic diaphragm, rather than a plate, eliminating the need for the accurately alined guide surface. Variations up to an inch or so are accommodated through the flexing of the diaphragm.

Britain's Hovercraft Development Ltd. has proposed an air supported vehicle traveling in a V-shaped track to be powered by a diesel or linear induction electric motor.

A number of concepts include the use of a linear induction motor, which is constructed by flattening out the rotor into a bar in the track and the stator coils are placed in the vehicle (positions may be reversed). General Motors is considering it to propel Hovair. Linear induction motors have captured the imagination of many investigators since World War I. Much of this effort has taken place in