PCC Streetcar - Origins

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 was tasked with producing 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.

It turned out that the PCC streetcar was a very good design. The standard car under the original 1935 specifications was 46 ft (14.0 m) long and 100 in (2.54 m) wide with later models 46.5 ft (14.2 m) long and 108 in (2.74 m) wide. Chicago, Detroit, Illinois Terminal, Pacific Electric, and San Francisco had longer cars, as long as 50.5 ft (15.4 m). Washington, D.C., had shorter cars (44 ft (13.4 m)) because of transfer table clearances. Many railways altered the car in various ways to fit their own needs, but most cars retained a standard appearance.

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, serving most conspicuously with Atlantic City Transit. 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 Hirshfeld both presented and published.

Pittsburgh Railways (PRCo) took delivery of PCC #100 in June 1936, the fourth order for a PCC car but the first PCC car delivered and the first in revenue service in the world. Production continued in North America until the early 1950s, with 4978 units built; thousands more PCCs and direct descendants were produced in Europe through the 20th century. The cars were very sturdy and many lasted a long time; well into the 1970s the majority of surviving North American streetcar systems used PCC cars, the systems which closed often selling their cars secondhand to the surviving operators. A handful still remain in service alongside modern vehicles, though most of the PCC cars functional today are operated by museums and heritage railways.

The first order of 99 cars was built in 1936 for Brooklyn, New York, by the St. Louis Car Company. The second order built (27) was for Baltimore and the third order went to Chicago, all by St. Louis Car Company. Clark Equipment Company built only one PCC, #1000, and the only aluminum PCC at that; this car completed the 100-car order for Brooklyn.

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.