3D Bullet Car

The Philadelphia and Western Railway faced serious competition when, in 1930, both the Reading and Pennsylvania Railroads electrified their commuter services between Norristown and Philadelphia. To counter this improved service, the P&W bought ten state-of-the-art aluminum Bullet cars in 1931. Designed in a wind tunnel, they regularly reached eighty mph in regular service. So robust was their design that they were to remain in service on the Norristown High-Speed line for sixty years. Mike Szilagyi

This 3D computer model started out in AutoCAD. First, 2D plans and elevations were drafted, based on blueprints of the Bullet car. The CAD drawing was built from the dimensions on the drawing, with subtle details filled in by tracing over the portions of the plan with a digitizer. Because the point of this was to generate an accurate drawing, a scanner was not used. Mike Szilagyi

The accurate 2D CAD drawing was then used as the basis for a 3D CAD model. All 3D geometry was built inside AutoCAD Release 12. The base AutoCAD package, with millions of installations worldwide, has actually had full 3D capability since the October 1988 unveiling of Release 10. DDvpoint and the UCS command are the main gateways from 2D to 3D in AutoCAD. Once there, five commands are all that is needed to generate any surface. Here, the Edgesurf command was used to generate the sleek Bullet's roof. Mike Szilagyi

3D Studio was used to render the AutoCAD-generated 3D model. Since its inception, 3D Studio has been able to read and write DXF files that contain 3D geometry. AutoCAD R13 was the first release able to read and write 3DS files. Windows-NT based 3D Studio MAX 1.1 had the ability to read and write 3D AutoCAD drawings directly. At the time it was hoped that Autodesk was working toward a single, unified file. Mike Szilagyi

This viaduct was built over the Schuylkill River at Norristown in 1912 to carry the P&W tracks over the river, one canal, and three railroads. It is still in use today. Lacking plans for the structure, data was gathered by visiting the bridge, carefully measuring the spans and documenting details with photographs. Like the Bullet car, the geometry was modeled in AutoCAD R12. Because of its repetitive structure, extensive use was made of the mirror and array commands. Mike Szilagyi

This photo of the viaduct, with a Bullet car rolling over it, was taken from the nearby Dekalb Street bridge in the spring of 1979. Though already almost fifty years old, the Bullets would soldier on for another ten years. That last decade pushed the limits of the Bullets and the Strafford cars too far, with several collisions and fires. One passenger was killed when a Strafford car lost brakes and rammed 69th Street Terminal, ending up inside the waiting room. The line was almost closed down in the early 1990's, before used Chicago El cars were brought in, while the new N5 cars were being built. Mike Szilagyi photo

More about the Bullet cars.