Rail Diesel Cars

Rail Diesel Cars, commonly known as RDCs or Budd Cars, hold a nostalgic place in American transportation history. In 1949, the Budd Company, owned by Edward G. Budd, introduced the first RDC prototype at Union Station in Chicago. RDCs offered a fast and affordable way to travel, commute, and transport U.S. Postal Service mail. Unique for their time, RDCs were self-propelled, each equipped with two diesel engines and exhaust pipes centrally located on the car.

From 1949 to 1962, a total of 398 units were built and used on rail lines worldwide. With commuting by train declining after World War II and railroads struggling to retain passengers, RDCs presented a more economical alternative to traditional passenger cars. The Budd Company developed four primary models (RDC-1, RDC-2, RDC-3, and RDC-4), plus a less common RDC-9 variant. The RDC-1, -2, and -3 models measured 85 feet in length and offered various combinations of passenger, baggage, and mail capacity. The RDC-4, at 73 feet, was designed exclusively for mail and baggage, while the RDC-9, an 85-foot model with a single engine, was not independently operable.

Each RDC had operator vestibules at both ends (except the RDC-9) with connecting doors, allowing for easy operation back and forth or linking multiple cars together. Stairs enabled boarding from both low-level rural platforms and high urban platforms. Lighter than traditional passenger cars, RDCs could be operated by a two-person crew.

Some facts about RDC:

• RDC-1 — passengers only, 90 seats
• RDC-2 — passengers and baggage, 70 seats (pictured right)
• RDC-3 — passengers, baggage, and a dinette, 49 seats
• RDC-4 — used only for Rail Post Office and baggage
• Truck Design — Each RDC sits on two twin-axle trucks
• Engine Placement — Diesel engines are located underneath and drive the inner axle of each truck via a drive shaft
• Power Generation — One engine drives a generator that provides light, heating, and air conditioning
• Cooling System — Radiators for exhaust and cooling are housed in a roof enclosure
• Redundancy — Engines operate independently so if one fails, the other can still propel the car
• Service Accessibility — Engine placement allows for easy access for service and repair