Gondola (rail)

History

The first gondola cars in North America were developed in the 1830s and used primarily to carry coal. Early gondolas were little more than flatcars with wooden sides added, and were typically small – 30 ft or less in length, and 15 ST or less in weight. Those cars were not widely used at first, because they could only be unloaded by workers shoveling out the cargo by hand, a slow and labor-intensive process. A solution to the problem was developed around the 1860s with the drop-bottom gondola: hatches were installed in the floor which could be opened at the destination, and workers using shovels directed cargo towards the hatches. Although it was an improvement over earlier gondolas, it still required manual unloading.

After the American Civil War, advances in technology, especially the development of steel, allowed new and larger gondola designs. New gondolas were built with steel sides and frames, although wood was retained for flooring since it was flexible and cheap to replace. The cars were often built to lengths between 40 and 50 ft, and gradually increased in capacity from around 30 ST to as much as 70 ST by the early to mid 20th century.

Gondola cars began to be built for specialized purposes and, depending on their intended cargo, the side heights could range from just 2 ft for bulk commodities such as sand, to 6 ft or more for loads such as pipes, and 10 ft or more for light cargos such as woodchips. Covered gondolas were also developed for cargos that had to be protected from the elements, such as newly milled steel. Increasingly, present-day loose-material loads are covered by airtight covers to minimize air pollution. Starting in the 1950s and 1960s, high-sided gondolas were used for coal, thanks to stronger car construction and the invention of rotary car dumpers, which allowed those gondolas to be emptied automatically.

Specialized car types

Rotary gondola cars

In the second half of the 20th century, coal haulage shifted from open hopper cars to high-sided gondola cars, which allowed a larger amount of coal per car since gondola cars do not include the equipment needed for unloading. However, since these cars do not have hatches for unloading the products shipped in them, railroads have used rotary car dumpers (mechanisms that hold a car against a short section of track while the car and track are slowly rotated upside down to empty the car) or other means to empty them. Such cars can be equipped with couplers that are free to rotate to allow dumping while the car is still coupled; a "double rotary" car has rotary couplers on both ends to allow it to be unloaded while it remains coupled to cars at each end. Rotary gondola cars are often nicknamed "bathtub gondolas" on account of their shape.

Coil car

Main article: Coil car

The coil car is a modified gondola designed specifically for carrying coils of metal.

Track ballast gondolas

Air-dump cars sometimes carry ballast. These gondolas are side-tipping, so they often are used to carry rock or dirt to add to an embankment, rather than dump crushed-rock ballast between the ties. Ballast is usually carried in bottom-door hopper cars, so that the ballast is dumped directly below the car, rather than to the side.

Notes

References

References

1. McAuliffe, Des. (1999). "The Snowtown to Port Pirie Line".
2. Schafer, Mike. (1999). "Freight train cars". MBI Pub.
3. . (January 2024). "General operations". *[[National Railway Museum, Port Adelaide]]*.
4. Erskine Ramsay, Revolvable Car Dumping Structure, {{US patent. 701764, granted June 3, 1902.
5. (October 5, 2021). "What Is a Coil Car?". Union Pacific.