Unit trains are now used for coal, grain, iron ore, hot steel slabs, and various raw materials. The capacity of new freight cars has been increased to the extent that new cars being delivered from the builders average 76 tons compared with 50 tons for those being retired. The most dramatic accomplishment since World War II has been the almost complete substitution of the diesel locomotive for the steam locomotive.

The whole character of this technological progress has been evolutionary in nature and the result of growing competition by other transport modes. Aggressive action has and is being taken to compete with freight competition but the same cannot be said about passenger traffic.

Previous Efforts to Improve Intercity Passenger Travel.-After World War II the railroads and their suppliers made a concerted effort to modernize the passenger train business. Table 1 summarizes some interesting characteristics of five advanced lightweight passenger trains that were put in service in the midfifties. It is interesting to note that the explorer train had one-third the first cost, one-third the weight, and one-third the operating expense (fuel) of conventional trains.

The following material has been extracted from a paper by W. W. Patchell, "The Technological Change and the Future of Passenger Traffic" given at Northwestern University Transportation Center Conference, January 1961:

In June 1954, the Eastern Railroad President's Conference appointed a committee to determine the type of rail passenger equipment which would meet the needs of the future. About the same time, General Motors developed its lightweight Aerotrain, to produce a service competitive with the bus or automobile. Two of these trains were built. One went into service on the Pennsylvania between New York, Philadelphia, and Pittsburgh. The New York Central ran the other between Chicago and Detroit. These trains later were purchased by the Rock Island, and are used in suburban service between Chicago and Joliet. During this same period, the Rock Island placed Jet Rockets in service between Chicago and Peoria. These were built by American Car & Foundry, which had been promoting the Spanish Talgo train. These trains are now used in Chicago suburban service. A Talgo train was also operated by the New Haven between New York and Boston.

Pullman Standard developed Train X, which is a type of Talgo train. The New York Central operated one train between Cleveland and Cincinnati, but is no longer in service. The New Haven also operated one of these trains between New York and Boston.

In cooperation with the Budd Co., the New Haven developed a train called the Hot Rod, to operate between Boston and New York. With the exception of the cab unit, the cars were basically the familiar Budd rail diesel car. The three New Haven trains operated under diesel power for their entire route, except in the Grand Central Station area, where they picked up current from the third rail for direct electric drive to the propulsion motors.

None of these New Haven lightweight trains is in service at present.

The Keystone was the Pennsylvania's contribution to lightweight train development. Although they have the heavyweight appearance of the earlier congressional equipment, which weighed 1,700 pounds per seat without the locomotive, the Keystone cars weigh only 1,200 pounds per seat. This is just about half of the weight per seat of the standard steel coach used in the New YorkWashington passenger service.

As a result of the experience with the tubular-type Keystone train, the Budd Co. designed and constructed its Pioneer III coach. It is mostly stainless steel with plastic interior wall and ceiling panels and molded fiberglas seats. This construction reduced weight per seat to less than 700 pounds.

By this time, there was a transition from development of long-distance passenger equipment to suburban service equipment. Recognizing the problems created by suburban service peak-hour loads, the railroads developed high capacity cars to reduce the tremendous investment needed to replace some of their higher maintenance cost equipment. One, primarily used by the midwestern railroads, where overhead clearances were not a critical problem, was the gallery type of suburban coach, such as the stainless steel car built for the Burlington. It has a weight per seat of 1,400 pounds including motive power. Passengers are seated on the first level in a 2 and 2 arrangement, and on the second level, in single-seat balconies, each with an aisle. Similar cars were built for the Southern Pacific, the Milwaukee, and the Northwestern.

In the east, the New York Central, Long Island, and New Haven introduced 3 and 2 seating for suburban service. This provided relatively high seating capacity on a single floor level, enabling these railroads to meet their clearance requirements.

Following development of the Pioneer III, the Pennsylvania persuaded Budd to develop a new lightweight suburban car, for use in its electrified territory. Six of these cars were purchased in 1958. They are constructed of stainless steel with plastic interiors. They are constructed of stainless steel with plastic interior walls and fiberglas stairwells. Utilizing 3 and 2 seating, they seat 128. Including the propulsion equipment, their weight per seat is 720 pounds, or almost one-half that of the Aerotrain.

In three of these cars, Budd used a new lightweight passenger truck known as the Dean truck, which Budd had developed for its Pioneer III coach, and which had been tested in 50,000 miles of operation in New York-Washington service prior to being considered for use in suburban service equipment.

This truck, as adapted for use with electric propulsion motors, reduced truck weight. There was a significant change in thinking with respect to power requirements. This involved a head-end power source for such auxiliary power requirements as heating, lighting, air conditioning, rather than the costly

self-contained units on each car. This principle was used in the Talgo-type trains, the Aerotrain, Train X, the Pioneer III, and the Pennsylvania's Keystone tubular train.

These lightweight trains were designed to have strong passenger appeal but the results were very discouraging. The John P. Doyle report dated June 26, 1961, "National Transportation Policy," Senate Report No. 445, cites some reasons why this happened.

Trains such as the Aerotrain were made as a unit so that they could not readily be broken for changing cars, even for maintenance. Initial passenger acceptance was generally very good but people began to object to the level of noise and vibration at the higher speeds. Breakdowns were so numerous on some trains that passengers stayed away because of unreliability.

Operating problems were encountered particularly on roads where part of the system is electrified and where only electric locomotives could be used in underground terminals. Another problem was that the light train weight did consistently trip signal activating devices.

This experience with lightweight trains in the 1950's as well as similar experience with articulated lightweight trains in the 1930's, highlights the lack of experience demonstrated at that time by both the few railroad operators who sponsored them and the equipment manufacturers in managing innovation. There was too little service testing prior to use and too little detailed systems analysis and operational planning.

The market for intercity passenger equipment on trunkline railroads in the United States has been small. About the only purchases of intercity equipment have been by two western railroads for deluxe cars for ultra-long-distance operation.

For suburban service, the market has been brisker. Dual-level or gallery cars, already described, are hauled by a diesel locomotive at one end, but capable of either direction, or push-pull operation by the installation of a remote control cab in the car at the other end from the locomotive.

Individually powered cars operated in trains by one engineman under multiple unit (MU) control are being installed in substantial numbers for suburban service by the limited number of railroads which are electrified. These cars constitute, in effect, a refinement of similar equipment operated since the turn of the century on electric rapid transit lines, and since 1910 in railroad commuter service.

More important, however, is the fact that the concept of individually powered passenger cars, operated as MU's, is receiving serious attention for a wider range of service. (It may be noted that the 320-mile high-speed Tokaido line in Japan is equipped exclusively with individually powered cars.)

Opportunities for intercity operation of MU electric cars are limited to the Washington-New Haven and Philadelphia-Harrisburg routes and to a short line between Chicago and South Bend.

Fortunately, the MU concept has also been applied to self-propelled diesel cars since the 1950's, so that it can be used on nonelectrified lines. The decline of local and branch line service has limited recent production of this kind of equipment in the United States, but successful application to longer trains over long distances in Britain and Japan, among other countries, gives promise of renewed and expanded use of this equipment in the United States in the future. First cost and maintenance expense of individually powered diesel cars tend to compare less favorably with those of locomotive-hauled trains of nonpowered cars as the length of the train increases. However, MU operation has the advantage of lower operating costs for shorter trains and, even for long trains, increased flexibility in adding and subtracting units en route, higher acceleration and braking, ability to maintain service despite breakdown of individual units and simplification of terminal operations.

Prior to the Civil War, American railroads were also faced with the problem that they were not compatible with each other. To ship goods from Philadelphia to Richmond, for instance, involved loading and reloading four separate times. The principal offender was gage-everything from 3 feet to 6 feet-but couplers, wheel flange height and many other factors also intervened. After the war the principle of interchangeable equipment was developed, cooperatively, by the major railroads and as mergers became common the progress was swift. The major shift occurred in 1886, when the southern railroads shifted from 5-foot gage to the standard 4-foot-81⁄2-inch gage in a single hectic day.

The result today is that a new coupler, a new brake system or the like is acceptable only if it can be used with other equipment.

The restriction on development is most oppressive and applies equally to both passenger and freight equipment. Thus in some cases an electric or diesel locomotive must have steam generation equipment because it might be used with passenger cars which require steam for heat, even on electrified roads.

Following is an examination of the development of railroad subsystems. A. Track and roadbed 1

For more than 125 years track has been constructed in its present manner, although the components have varied and improved techniques have been introduced since man first laid slabs of lumber on the ground to keep his wheels from sinking into the mud.

1. Rail

The steel rail, basic to all railroad and transit operations, has been used in one form or another since the late 18th century. The steel rail used today became the standard following the Civil War but generally was made of iron until 1870. Probably no other single railroad product has been researched as much as the steel rail. It has appeared in many shapes and forms and numerous combinations of alloys. By the end of the 19th century there were 119 patterns of rails in 27 different weights.

Control-cooling has increased longevity of rail to the point where it can be expected to bear 600 million gross tons of traffic over its life in tangent track, and less on track with more curvature.

Rail with beneficial amounts of silicon, called high-silicon, has been utilized successfully to reduce wear on curves. Increased life of 150-200 percent over that of control-cooled rail have been obtained under conditions of heavy traffic density. Heat treatment by flame hardening and induction hardening is claimed to increase rail life 300-800 percent above that of control-cooled, but is presently considered economically feasible only for track on heavy curves or grades sustaining high density rates of traffic and possibly adjacent to station platforms. Several processes have been developed which utilize flame or induction heating of the railhead with air or water quenching, and promise to bring reductions in cost which may find economical advantages for more general use.

Fully heat-treated oil quenched rail is used mainly for track structures such as switches and crossings sustaining repetitious impact and abrasion.

Rail joining by welding into continuous lengths is being utilized to a large extent in renewal of track by the railroads. Continuous welded rail has found favor because of the resultant cost reductions in maintenance to track and rolling stock. Rail previously removed from track for rail-end-batter can be left in for up to 50 percent additional use as welded track. Increased use of welded joints has brought reductions in joining costs to lower than that for bolted.

Advanced methods and equipment have been developed for electric-flash and gas-pressure welding types, which are the more favored, considered more reliable, and used in fixed plants to produce large quantities of strings 1,300-1,400 feet in length. Portable gas welding and induction welding units presently being tested would facilitate the joining of rails in track for new or repair installations. Rail surface grinding has brought beneficial results to operating transit systems and railroads. Heretofore, rail grinding has been used on a local repair basis and mainly for correction of corrugations. Scheduled dressing is being adopted by more and more systems for the benefits in riding quality, preventive measures against defects, and reduced maintenance of wheels. It is considered that rail grinding on new track installation prior to vehicle operation, and at periodic intervals thereafter, will provide a uniformity of surface free of scale, surface defects, and installation marks which produce objectionable high-frequency vibrations and possibly rail corrugation. Large scale operations require selfpropelled grinding cars.

2. Rail fasteners

The cut spike is the basic type of rail fastener in use for wood tie and ballast track. Improvements and adaptations have come about for means of reducing plate cutting of ties, by provisions to fill plate holes and prevent shifting. These adaptations are available in the form of anchor studs, twisted shank cut spikes and hairpin spikes, and are considered superior for anchoring of tie plates.

The cut spike is still used extensively for line spikes in maintaining gage. Screw spikes have never been successfully used for rail fasteners because of wood fiber stripping within the tie.

1 Much of the material in this section has been extracted from a report prepared for Parsons BrinckerhoffTudor-Bechtel by Kaiser engineers, "Data Collection and Analysis Report Track and Roadbed Investigations for Test Track Program of San Francisco Bay Area Rapid Transit District.