PCC streetcar

Origins

The "PCC" in this car's name comes from the name of a design committee formed in 1929 as the Presidents' Conference Committee and renamed the Electric Railway Presidents' Conference Committee (ERPCC) in 1931. This group's membership consisted mostly of representatives of some of the larger operators of urban electric street railways in the United States. Three interurban lines and at least one "heavy rail," or rapid transit, operator - the Chicago Rapid Transit Company - were represented as well. Also included on the membership roll were manufacturers of surface cars (streetcars) and interested component suppliers. The ERPCC goal was to design a new and modern type of streetcar that would better meet the needs of the street railways and their customers. The committee prepared a detailed research program, conducted extensive research, built and tested components, made necessary modifications, and, in the end, produced a set of specifications for a complete vehicle of a set design (albeit one with a modest list of available options and at least some room for customer customization) built with standard parts as opposed to a custom designed carbody with any variety of different parts added to it depending on the whims and requirements of the individual customer.

The design patents resulting from the work of the ERPCC were transferred to a new business entity called the Transit Research Corporation (TRC) at the time of the committee's expiration in 1936. Although this company would continue the work of research on improvements to the basic design of the car and would issue sets of specifications three times in the ensuing years, because TRC defined a PCC car as any vehicle which utilized patents on which it collected royalties, it was formed for the primary purpose of controlling those patents and promoting the standardization envisioned by the ERPCC. The company was funded by its collection of patent royalties from the railways which bought PCC cars. The company was controlled by a voting trust representing the properties which had invested in the work of the ERPCC. Although a participant in Committee meetings, trolley manufacturer J. G. Brill and Company brought a competitive design—the Brilliner—to market in 1938. With Raymond Loewy designed elements, very similar to the PCC look, the Brilliner attracted no large orders, being built only for Atlantic City Transit and the Red Arrow Lines in Philadelphia. Fewer than 50 were sold.

A significant contribution to the PCC design was Noise Reduction with extensive use of rubber in springs and other components to prevent rattle, vibration, and thus noise and to provide a level of comfort not known before. Wheel tires were mounted between rubber sandwiches and were thus electrically isolated so that shunts were used to complete ground. Resilient wheels were used on most PCC cars with later heftier cousins known as Super-Resilient.

Gears were another source of considerable noise, solved by employing hypoid gears which are mounted at a right angle to the axle, where three of the six teeth constantly engaged the main gear, reducing play and noise. All movable truck parts employed rubber for noise reduction as well. "Satisfactory Cushion Wheel of Vital Importance; Develop New Truck Design; Generous Use of Rubber" are headings within a paper that Chief Engineer Clarence F. Hirshfeld both presented and published.

After a specification document suitable for purchasing cars was generated by TRC, orders were placed by 8 companies in 1935 and 1936. First was Brooklyn & Queens Transit Co. (B&QT) for 100 cars, then Baltimore Transit Co. (BTCo) for 27 cars, Chicago Surface Lines (CSL) for 83 cars, Pittsburgh Railways Co. (PRCO) for 101 cars, San Diego Electric Railway (SDERy) for 25 cars, Los Angeles Railway (LARy) for 60 cars, and then Boston Elevated Railway (BERy) for 1 car. In late 1935 or early in 1936 Westinghouse Electric pressed for one car to be equipped with their electrical equipment for testing in Pittsburgh, since the Brooklyn order would have all cars equipped by General Electric, and Clark Equipment Co. pressed for one car to be made by them of aluminum for delivery to B&QT. Agreements among the parties were reached whereby St. Louis Car Co. would build 101 essentially identical cars and Clark would build one of its own body design.

Brooklyn received its first car #1001 on May 28, 1936, PRCo took delivery of car #100 on July 26, 1936, and Baltimore received its first car on September 2, 1936. In the late 1936 discussions of operating experience it was noted that the Brooklyn car had run 3000 miles by the time the Pittsburgh car had run 1000 miles. The first car to be placed in a scheduled public service was PRCO #100 in August and B&QT launched its first scheduled service with a group of cars on October 1, 1936, followed by CSL on November 13, 1936. Production continued in North America by St. Louis Car Co. and Pullman-Standard until 1952, with 4978 units being built. Under license to use the designs patented by TRC, thousands more PCC and partially PCC type cars were produced in Europe through the last half of the 20th century. The cars were well-built and many hundreds are still in operation. The majority of large North American streetcar systems surviving after 1935 purchased PCC streetcars; those systems which eventually closed down streetcar operations often selling their cars to the surviving operators. Several dozen still remain in public transit service, such as in Boston, and in Philadelphia, Kenosha, San Diego and San Francisco following extensive overhauling. All other surviving and functional North American PCC cars are operated by museums and heritage railways.

Washington, DC, PCCs were unique because of conduit plows which collected current from a slot between the rails into which the plow dipped, contacting positive and negative rails under the street on either side. At the city limits were "plow pits", where the plow was dropped and removed, the trolley pole raised, and the car then continued on its way, utilizing overhead wire; the process was reversed in the opposite direction into Washington.

"The PCC car was not just another modular vehicle but the result of the only systems engineering approach to mass producing a rail car." Research into passenger comfort resulting from vibrations, acceleration, lighting, heating and cooling, seat spacing, cushion height, space for arms, legs, standing passengers, economies of weight affecting maintenance, cost of power, reduced wear of components and track. Dimensions were established to fit the majority but could easily be changed for special situations. Windows were spaced to match seating.

While some of the components in the PCC car had been used before—resilient wheels, magnetic braking, sealed gears, and modular design to name a few—the ERPCC redesigned, refined, and perfected many of these while developing new acceleration and braking controls and put them all in one package. The PCC is far more than a good design, it is an excellent design with modern transit rail vehicles essentially upgrading the design with the most recent technology.

Performance

Westinghouse developed the XD-323 rotary accelerator with 99 points; it was installed in the first PRCo car, #100, and minor modifications allowed use in the last PCCs produced in North America for San Francisco in 1952. Resistance ribbons were mounted to each point around the outside edge of the accelerator. An arm rotating in the center had rollers on either end which cut out resistance alternately as it rotated approximately 180 degrees. This same accelerator was also used for dynamic braking; when the power pedal was released the accelerator sought optimum braking for the speed, which prevented a lag when the brake pedal was depressed. General Electric Developed a control system for PCC cars that mirrored the Westinghouse scheme in function, although not in simplicity or maintainability. With the GE commutator motor controller operating by air pressure, it had to be redesigned with the advent of the All-Electric PCC. Acceleration was variable between 1.5- and 4.75-mph per second depending upon the depression of the power pedal with the accelerator advanced automatically by a low-voltage pilot motor. Service braking was also variable and the maximum dynamic application decreased speed by 4.75-mph/s; pressing the brake pedal into emergency also brought the friction and magnetic brakes into play providing a maximum deceleration of 9.0-mph/s. Compared to a maximum of 14 points on old time equipment, the PCC was considerably smoother.

Most PCCs employed three pedals with a dead man's switch to the left, brake in center, and power pedal on the right. Depressing the brake about half way and then releasing the deadman pedal put the PCC in "park". Lifting the deadman alone would apply all brakes, drop sand, and balance the doors so they could be pushed open easily. Chicago used "bicycle-type levers" for power and brake but converted some cars to two pedals. St. Louis Public Service Co. (SLPS) used two pedals, both with heel interlocks. The right pedal is the brake; depressing this pedal about half way while lifting away from the heel applied "park". Once the brake is released the heel need not be engaged with the interlock (although a professional driver is to cover the brake at all times.) The left pedal applied the power and the heel interlock had to be engaged at all times since it was the deadman; only when the brake was in "park" could the deadman be disengaged.

SLPS is unique in that all 300 of their PCCs are All-Electric with the 1500s ordered in late 1939, the 1600s ordered late 1940s and the 1700s in January 1945. SLPS was the rolling laboratory for All-Electrics and what was learned here was applied to the post-WW2 All-Electric Demonstrator in the Fall of 1945.

From 1936 to 1945, PCC cars were 'Air-Electrics' with friction brakes, doors, and windshield wipers operated by air pressure. PRCo PCC 1600 of 1945 was the post WW2 All-Electric Demonstrator which eliminated the air compressor and associated piping while incorporating such features as standee windows, a sloped windshield to eliminate night time glare, redesigned back end, forced-air ventilation, and other features. Dynamic brakes were the service brake on all PCCs; when almost stopped, friction brakes completed the stop and held the car in "park". Dynamic brakes slowed the "Air" cars to 3.0-mph at which point a lock-out relay allowed automatic application of air-applied friction brakes against each of the eight wheels. On All-Electric cars the dynamics were effective to 0.75-mph where the lockout relay then allowed a spring applied friction brake to engage a drum on each of the four motor drive shafts; this completed the stop and held the car in park. Drum brakes were released by an electric solenoid operating from low-voltage battery power; a power failure would prevent the drums from releasing which would prevent power application, a fail-safe feature. Drum brakes were quite popular and greatly reduced maintenance thus some "Air" cars were retrofitted with drums. Four magnetic brakes, one between the wheels on each side of each truck, applied additional braking for emergency stopping where all brakes were generally employed.

"These performances [acceleration and braking] enable the P.C.C. car to out-pace the average automobile which, in America, is of substantially higher performance than the typical British vehicle."

North American body variations

In North America there were two main body standards, 1936 and 1945, sometimes called pre-war and post-war, the most prominent difference being the windows.

The pre-war cars usually had a right side arrangement of front door, five windows, center door, five windows, and one large rear quarter window. These cars were 46 ft (14.0 m) long and 8 ft 4 in (254 cm) wide. There were variations, Washington, D.C. ordered shorter cars, at 44 ft (13.4 m), with one less window, while Chicago ordered longer and wider cars, at 50 ft 5 in (15.4 m) by 8 ft 9 in (267 cm), with a three-door arrangement

Post war cars had a rationalized window arrangement. The windows and pillars were narrower, and there were small "standee" windows above each window. Right side arrangement usually was front door, 7 windows, side door, four windows, and two rear quarter windows. Most post-war cars had a length of 46 ft 5 in (14.1 m). Other body differences were a recessed windshield and wider doors. There were far fewer variations of this style, width being the most common.

Most double ended cars, at 50 ft 5 in (15.4 m) long by 9 ft (270 cm) wide, were larger than standard, with different door arrangements. Only Dallas ordered standard size double ended cars. All double ended cars retained the pre-war style body until the end of production.

Toronto's PCC featured a green bull's eye light on the front of each car above the destination sign.

Rapid transit cars

There were four rapid transit companies on the committee, but the primary focus was streetcars, rapid transit development was slower. The difference in operations between the systems also made standardization difficult.

By 1940, Brooklyn had five 3 section articulated trainsets with PCC components, after WWII Chicago ordered four similar trainsets. Chicago ordered two from Pullman and two from St. Louis, with different equipment, so that competing manufacturers could be directly compared. Experience from the trainsets influenced the following car standards.

Cars were to be approximately 48 ft (14.6 m) long (the Chicago maximum, Boston had some 55 ft (16.8 m) long) with one cab per car arranged in "married" two car sets, a double ended single car variant was possible. Number and type of doors and windows, interior layout, and width of cars varied with each system. Boston had two sizes, the longest at 55 ft (16.8 m), and narrowest at 8 ft 4 in (254 cm), Cleveland had the widest at 10 ft 4 in (315 cm).

Trucks were a major focus, both Clark and St. Louis developed trucks with 28 in (710 mm) wheels and a 70 mph (110 km/h) maximum speed, but only Boston used them, Clark B10s on 40 cars. Chicago used streetcar type trucks, with 26 in (660 mm) wheels and a speed of 50 mph (80 km/h), adequate for their system. When Clark stopped building railroad equipment in 1952 PCC trucks were no longer available, Boston and Cleveland then used non PCC trucks with 28 in (710 mm) wheels.

Chicago ordered the first of 770 (720 + 50 double-ended) cars in 1948 (before the standard, which they influenced), Boston (40, then later 100) in 1950, and Cleveland (70 + 18 double-ended) in 1952. Chicago's first 200 cars were entirely new, but in 1953 they started using components salvaged from new, but no longer needed, streetcars. Toronto, on the committee, did not buy any, nor did Brooklyn, who had bought the first five trainsets.

240 PCC rapid transit cars were built in four years, from 1948 to 1952, then 438 cars with non-PCC trucks until 1957, the last of Chicago's 570 cars built with salvaged components were delivered in 1958. Some Chicago cars were in regular service in 1990, car #30 made its last revenue run in 1999.

North America

PCC cars were initially built in the United States by the St. Louis Car Company (SLCCo) and Pullman Standard. Clark Equipment built the only aluminum-body PCC as well as all narrow gauge B1 trucks for Los Angeles, all the standard and broad gauge B2 trucks both air- and all-electric, and the B2B trucks used under PRCo 1725–1799 and Toronto 4500–4549. SLCCo built all B3 trucks, both standard and broad gauge. PCC cars for Canadian cities were assembled in Montreal, Quebec by Canadian Car and Foundry from bodies and trucks supplied by St. Louis Car.

Westinghouse (Westinghouse Electric, Westinghouse Air Brake Company, Canadian Westinghouse Co.) and General Electric both supplied electrical packages and brake components which were designed and built in cooperation with the ERPCC. The customer specified the equipment which was to be installed, performance was similar and most cities ordered from both suppliers. Since Westinghouse was home based near Pittsburgh, PRCo ordered 75% of its PCC fleet with Westinghouse equipment, the balance with GE. Indeed, PCCs are often identified as either Westinghouse or GE.

The last PCC streetcars built for any North American system were a batch of 25 for the San Francisco Municipal Railway, manufactured by the St. Louis Car Company and delivered in 1951-2.

Europe

The PCC technology was exported to Europe, with La Brugeoise et Nivelles (now the BN division of Bombardier) of Bruges, Belgium, building several hundred streetcars that saw service in Brussels, Antwerp, Ghent, The Hague, Saint-Étienne, Marseille and Belgrade (the latter city buying vehicles initially used by the Belgian Vicinal railways).

The first European PCC cars were probably the ones developed in 1942 by Italian Fiat for the Madrid tramway system. Due to the progression of World War II, delivery of the units from Italy had to be stopped and eventually 110 cars were built in Spain to the Fiat design, either by CAF (Compañía Auxiliar de Ferrocarriles) in Beasain or MMC (Material Móvil y Construcciones) in Zaragoza. These units worked in Madrid until May 1972

ČKD Tatra of Prague also bought a PCC license, and built 18,680 PCC-based streetcars of the Tatra T1, Tatra T2, Tatra T3 and Tatra T4 models. Most numerous was type Tatra T3; 14,113 units were sold worldwide, mainly in former eastern bloc countries. ČKD Tatra had begun marketing to the rest of the world until 2000, when the company faced a bankruptcy and reorganization. The tram business was sold to Siemens SKV, who discontinued these products. Variants and reconstructions of T3 cars (usually with low-floor centre sections) continue to be manufactured by Czech tram-builders such as Skoda subsidiary Pars Nova and Pragoimex. The Tatra PCCs are by far the most numerous PCCs in the world.

Another Central European company producing PCC cars (though not licensed) was Polish Konstal in Chorzów, Upper Silesia. The Konstal 13N type borrowed heavily from the design of the CKD Tatra T1 (but with Belgian electric equipment) and was used in Warsaw until December 31, 2012. Newer 102N, 102Na and 105N types, produced 1969-1979, used 13N's electrical equipment. After many modernizations, the upgraded type Konstal 105Na and later versions based on it were still produced until the early 2000s (though with modern electronic equipment) by Konstal, which was bought by Alstom in 1997. 105Na generation cars are still used in all tram-towns in Poland.

Largest fleets

The following are known figures (2008.09.13):

Figures for Tatra trams are from Wikipedia articles on the respective tram models.

North America

In North America, most PCC-based systems were dismantled in the post-war period in favor of bus-based transit networks. Of the rail transit systems that survived this period, most had replaced their PCCs with modern light rail vehicles (LRVs) by the early 1980s. A few sites have only recently concluded operation with PCCs:

As of 2005, there are still a few places in North America where transit agencies employ PCCs in true revenue service (as opposed to short-run or intermittent heritage railway service). Of these, only one has been in service continuously since the PCC's glory days:

Not considered historic equipment, the PCC cars in use on the Mattapan-Ashmont line represent the oldest cars still in revenue service, originally built between 1943 and 1946. These cars are also the only air-electric PCCs still in regular service in North America. Several retired PCCs from Boston are now at the Seashore Trolley Museum.

Beginning in the late 1990s, several cities began to make use of historic PCCs to serve historic streetcar lines that combined aspects of tourist attractions and transit:

As many cities contemplate new transit projects, PCC-based streetcar lines are an attractive option as they are relatively low cost and can serve as a tourist attraction in and of themselves, especially on routes through historic city centers.

Europe

Pre-war tram networks remain largely intact in a number of European cities, and many still use PCCs as part or all of their rolling stock. Late-model PCCs remain in use in Belgium. The vehicles used in Antwerp and Ghent are metre-gauge, while those used in Brussels are standard-gauge. One of the peculiarities of the four-axle Brussels PCC vehicles is that some of them have been equipped with bogies and electric motors acquired second-hand in the United States from decommissioned streetcars from Kansas City, Missouri, and Johnstown, Pennsylvania. The last of the originally 171 four-axle class 7000 PCC cars in Brussels were withdrawn on February 12, 2010, with the articulated PCCs (130 class 7700 six-axle cars and 60 class 7900 eight-axle cars) remaining in service.

The tram system of Sofia, Bulgaria has 16 lines totaling 221 km served by 190 trams, some of which are Tatra PCCs. In Romania, Bucharest's extensive tramway network features a large fleet of Tatra T4R PCCs.

The largest number of PCCs (Tatra models) operate in Russia and countries of the former Soviet Union.

Several tramways in the Czech Republic and Slovakia still use Tatra PCC cars, while many in Poland still operate Konstal trams that started out with PCC equipment. Some in the former East Germany also still use them, but many have been extensively modified.

Gothenburg tram types M25, M28 and M29, delivered between 1958 and 1967 resemble the PCC cars in appearance only, since they are quite different technically.

German manufacturer DUEWAG produced a large number of GT6 and GT8 Streetcars for many German and European cities after 1951. Those cars were basically a modernized version of the PCC car, adapted to the specific requirements of European cities.

Latin America

PCC cars were also exported to Latin America, although not in great numbers, to Mexico and Buenos Aires particularly, in Buenos Aires they ran through exclusive rights of way on the suburban Urquiza Line for a while, these were modified at the ends to operate in two, three or four-sectioned articulated formations like most modern LRVs.