on the continued insistence of these companies change did begin to take
place. Before this, and with almost every type of commodity (liquid or solid), railroads used a combination of boxcars, flatcars, and gondolas to haul everything from lumber and coal to crude oil and water (by use of barrels). The inefficiencies of hauling liquids this way (barrels meant much less of the commodity could be transported
and barrel construction was never seal-tight so they often leaked or
were easily damaged in transit) quickly became obvious not only by the oil companies but also other businesses which had their liquid goods shipped via railroads.
The earliest version of tank cars, or oil car as it was known at the
time, began to appear in the early 1860s still during the Civil War.
Essentially, a standard flatcar was employed with two or three vertical
vats placed on top. Unfortunately, the design had several flaws; the
most obvious was that it could not hold very much product due to height
and width issues. Additionally, however, the wooden vats leaked. By
the late 1860s following the war the first true tank car began to take
shape, transitioning from an early vertical vat-on-flat-car design to a
horizontal iron tank which was mounted to a traditional flat car,
roughly similar to what is commonly used today featuring a top dome to
load the product as well as a discharge valve at the bottom. This new
design allowed for much more of a commodity type to be shipped via one
car and quickly became widely used, especially to haul crude oil.
|A DuPont owned-tanker, #8654, is seen here on the Rip Track in Pinoca Yard at Charlotte, North Carolina on April 12, 2006.|
By the 1870s and 1880s tank cars were in widespread use across the industry
not the least of which was due to the fact that the oil/petroleum
business was growing into a very profitable venture for railroads.
Despite the better design the car was still traditionally built with
wood at this time where the horizontal tank was fastened to a flatcar.
However, as the 20th century progressed the car was constructed of better materials. For instance, with the development of steel and welded seams the car
was much stronger and thus could be built larger to haul much heavier
loads. Also during the 20th century many more commodity types became
available from eatable liquids to various oil products, which required
differing types of tank cars to be built (such as those with interior glass-linings to accommodate edible commodities and chemicals).
Despite the widespread use of the tanker by the late 19th century railroads still found the car somewhat of annoyance since it typically could only be used to haul one product. For instance, a car
carrying oil could not haul any other type of liquid, such as a
food-based product. This led to the rise of privately-owned rail car fleets,
especially within the petroleum and chemical industry. Throughout the
first half of the 20th century the car's demand continued to climb,
first with the introduction of the automobile and then later during both
World Wars with a brief decline during the great depression. Today, most tankers are privately owned and as mentioned above carry a wide range of products from industrial to food-based.
Over the last half-century or so the tank car's overall design
has not changed significantly, with any alterations within the general
design itself to accommodate various commodities (such as differing
positions of the dome, walkways, and pressurized/non-pressurized railroad cars). If you are curious as to what a car may be carrying their product is usually labeled on the lower-right hand corner of the car
along with other reporting marks (and will say something such as
"ammonia," "chlorine," or some type of acid). Given the fact that today
there are so many differing types of bulk liquid commodities to carried
on the railroads the tanks car will certainly always be one type of freight cars used by the railroad industry for years to come.
|Trinity Industries Leasing Company (TILX) tanker #160211 carrying sodium hydroxide solution moves within a freight train consist on the evening of December 30, 2006.|
For more reading about tank cars consider the book, Freight Train Cars,
from Mike Schafer, one of the leading authors covering all corners of
the railroad industry (from its history to present day operations). The
book gives an excellent general history and overview on all of the common freight car
types and if you are interested in learning more about them, or you are
simply looking to better understanding their history and development
you should very much enjoy Mr. Schafer’s book. If you're interested in
perhaps purchasing this book please visit the link below which will take
you to ordering information through Amazon.com, the trusted online shopping network.