Some of the main benefits to constructing railcars from stainless steel include:
- high energy-absorption at impact
- a greater level of fire-resistance
- less likely than carbon steel to be weakened by corrosion.
The superior strength and corrosion-resistance of stainless steel mean thinner sections and panels can be used, making it more cost-competitive in the long run. Furthermore stainless steel panels do not require painting, providing further cost and weight savings. While weight may not seem an obvious item of concern for trains, consider the benefits on commuter rail links and metros, particularly those travelling above ground. However in the early days, stainless steel had to prove its worth to the rail industry.
Proving the strength of stainless railcars
It’s now over 80 years ago that the world’s first stainless steel train thundered down the tracks in the United Station. It was built in 1934 by the Edward G. Budd Company of Philadelphia. It was introduced to the American public in the most dramatic way possible – a thousand mile, dawn-to-dusk, non-stop dash from Denver to Chicago. The train broke all records, having reached a top speed of 112 miles per hour and averaged 78 miles per hour. The cost of fuel for the diesel engine was just $17!
Mr. Budd expected orders for stainless steel trains to pour in but that didn’t happen. The company was producing only an average of about ten cars per month. It was rumoured that most railroad men looked on cars only a third the weight of a standard Pullman car as fragile toys that would crumple like paper in an accident, despite the company’s claims that their trains were as strong as any.
Mr. Budd and his staff finally decided the only way out would be to test an entire car in compression. That had never been done before. The Association of American Railroads (AAR) accepted that procedure and stipulated that it should withstand an 800,000 pound load. In 1939 the Budd Company ordered a horizontal hydraulic compression machine and built a test house with a railroad track leading into it. Budd engineers realized that the recently developed strain gauges could be applied to the car at certain critical locations to determine during the test which sections of the car were over-designed and which could be strengthened. With this information design modifications could be made to improve future models. The car to be tested would be one stripped down to the stainless steel skeleton. On the day of the test a dozen engineers and technicians monitored the strain gauge recorders to give notice of any sudden strain increase.
The spot welds were considered the most vulnerable parts of the structure. The load reached the 800,000 pound requirement without incident and was then continued slowly to a load of 1,340.000 pounds, almost 70% more than the AAR requirement, at which point the test was stopped. It was not planned to continue the test to destruction.
Budd could then justify their claim of great strength but the Second World War had started and train building was discontinued. After the war the orders for stainless steel trains began to pour in and
Budd went on to manufacture 10,000 stainless steel cars before the company closed in 1987.
Below: The Flying Yankee at the Nashua, New Hampshire station in March 1935, shortly after being put into service. Photo courtesy of the Flying Yankee Restoration Group.