Rotary car dumper

Last updated
Rotary Railcar Dumper at 45-Degree Rotation Heyl & Patterson Rotary Railcar Dumper.jpg
Rotary Railcar Dumper at 45-Degree Rotation

A rotary car dumper or wagon tippler (UK) is a mechanism used for unloading certain railroad cars such as hopper cars, gondolas or mine cars (tipplers, UK). It holds the rail car to a section of track and then rotates the track and car together to dump out the contents. Used with gondola cars, it is making open hopper cars obsolete. Because hopper cars require sloped chutes in order to direct the contents to the bottom dump doors (hatches) for unloading, gondola cars allow cars to be lower, thus lowering their center of gravity, while carrying the same gross rail load. The "Double Rotary" coal gondola or coal hopper is required for compatibility (the "Double Rotary", here, referring to cars that have rotary couplers on both ends instead of one end).



In 1893, Timothy Long filed for a patent on a rotary car dumper. [1] This dumper required the car to be uncoupled because the dumper rolled the car to the side as it dumped. In 1901, Erskine Ramsay filed for a patent on a rotary dumper where the center of rotation of the dumper was aligned with the coupling. [2] When combined with Janney couplers that were free to rotate, this permitted dumping cars without uncoupling them from the train.

The rotary mine-car dumper offered by the Ottumwa Box-Car Loader Company in 1909 could dump five relatively small mine cars per minute. Prior to this, the common method of dumping mine cars was to tip them endwise. [3]

By 1921, the Car Dumper Equipment Company was offering a wide variety of rotary dumpers, including not only standard gauge dumpers, but also dumpers for use on mine railways; some of the latter were designed to dump an entire train in one operation. [4]


The primary alternative to rotary dumping has long been provided by a wide variety of self-unloading cars. Most of these are bottom-dump cars of various sorts, equipped with doors of one sort or another at the bottom to allow bulk cargo to be unloaded by gravity. Drop-bottom gondolas, for example, are low-sided open-topped cars where much of the floor of the car is composed of trapdoors. [5] [6] While drop-bottom cars could usually be used for other purposes, side-dump cars and hopper cars with sloping floors to guide the cargo to unloading doors can only be used for bulk cargo. [7] [8] All of these have the advantage that they can be unloaded anywhere, but the disadvantage that any imperfection in the seals of the doors allows material to spill onto the track.

In the mining industry, the long established standard for dumping mine cars was to run them into horns at the ends of the rails at the tipple. The inertia of the car would cause it and sometimes a short segment of hinged rail to tip forward, dumping the load out the end of the car. [9] Some of these dump mechanisms completely overturned the car end-for-end, and some allowed the car to continue onward after being dumped. [10] In the 19th century, a patent was issued for a machine to tip entire railroad cars endwise for unloading. [11]

Bulk cargo such as grain shipped in boxcars poses particular problems. The Ottumwa Box Car Loader Company built boxcar unloaders that both tipped the car sideways and rocked it end for end so that the cargo would spill out the side door. [12] One of these machines was in use in Portland, Oregon in 1921. [13]

See also

Related Research Articles

Railroad car Vehicle used for carrying cargo or passengers on rail transport system

A railroad car, railcar, railway wagon, railway carriage, railway truck, railwagon, railcarriage or railtruck, also called a train car, train wagon, train carriage or train truck, is a vehicle used for the carrying of cargo or passengers on a rail transport system. Such cars, when coupled together and hauled by one or more locomotives, form a train. Alternatively, some passenger cars are self-propelled in which case they may be either single railcars or make up multiple units.

Boxcar Enclosed railroad car used to carry freight

A boxcar is the North American (AAR) term for a railroad car that is enclosed and generally used to carry freight. The boxcar, while not the simplest freight car design, is probably the most versatile since it can carry most loads. Boxcars have side doors of varying size and operation, and some include end doors and adjustable bulkheads to load very large items.

The Somerset Railroad is a railroad that operates in Niagara County, New York. However, this railroad isn't part of its own company with its own motive power. The railroad is sometimes mistaken as being classified as a Shortline, however it is not a shortline. It is currently operated by CSX Transportation. The railroad was built with the primary objective of providing coal to the Kintigh Generating Station, also known as the Somerset Power Plant, a 675 megawatt coal-fired power plant located in Somerset, New York. The railroad was built in 1983 by the New York State Electric and Gas Co. using new and old rights of way. From Lockport, New York, it runs on the defunct International Railway Co. (IRC) interurban line opened in 1900 under the name Buffalo, Lockport & Olcott Beach (BL&OB) which became part of the IRC in 1902. From Newfane, New York, the SOM sweeps off the IRC to the Hojack Line in Appleton, New York, to West Somerset in the Town of Somerset. It then swings off on new trackage to a series of spurs and a loop at the Kintigh Generating Station.

Dump truck Truck which can tip its bed, dumping its contents

A dump truck, known also as a dumping truck, dump trailer, dumper trailer, dump lorry or dumper lorry or a dumper for short, is used for transporting materials for construction as well as coal. A typical dump truck is equipped with an open-box bed, which is hinged at the rear and equipped with hydraulic rams to lift the front, allowing the material in the bed to be deposited ("dumped") on the ground behind the truck at the site of delivery. In the UK, Australia, South Africa and India the term applies to off-road construction plants only and the road vehicle is known as a tip lorry, tipper lorry, tipper truck, tip truck, tip trailer or tipper trailer or simply a tipper.

A hopper car (US) or hopper wagon (UIC) is a type of railroad freight car used to transport loose bulk commodities such as coal, ore, grain, and track ballast. Two main types of hopper car exist: covered hopper cars, which are equipped with a roof, and open hopper cars, which do not have a roof.

Bulk material handling

Bulk material handling is an engineering field that is centered on the design of equipment used for the handling of dry materials. Bulk materials are those dry materials which are powdery, granular or lumpy in nature, and are stored in heaps. Examples of bulk materials are minerals, ores, coal, cereals, woodchips, sand, gravel, clay, cement, ash, salt, chemicals, grain, sugar, flour and stone in loose bulk form. It can also relate to the handling of mixed wastes. Bulk material handling is an essential part of all industries that process bulk ingredients, including: food, beverage, confectionery, pet food, animal feed, tobacco, chemical, agricultural, polymer, plastic, rubber, ceramic, electronics, metals, minerals, paint, paper, textiles and more.

Gondola (rail) Open-top railroad freight car used for carrying loose bulk materials

In US railroad terminology, a gondola is an open-topped rail vehicle used for transporting loose bulk materials. Because of their low side walls, gondolas are also suitable for the carriage of such high-density cargos as steel plates or coils, or of bulky items such as prefabricated sections of rail track. Gondolas are distinct from hopper cars in that they do not have doors on their floor to empty cargo.

Covered hopper

A covered hopper is a self-clearing enclosed railroad freight car with fixed roof, sides, and ends with openings for loading through the roof and bottom openings for unloading. Covered hopper cars are designed for carrying dry bulk loads, varying from grain to products such as sand and clay. The cover protects the loads from the weather. Dry cement would be very hard to unload if mixed with water in transit, while grain would be likely to rot if exposed to rain.


A tipple is a structure used at a mine to load the extracted product for transport, typically into railroad hopper cars. In the United States, tipples have been frequently associated with coal mines, but they have also been used for hard rock mining.

Rail freight transport Train that carries cargo

Rail freight transport is the use of railroads and trains to transport cargo as opposed to human passengers.

Bulk cargo Commodity cargo transported unpackaged in large quantities

Bulk cargo is commodity cargo that is transported unpackaged in large quantities.

A dumper is an off-road vehicle designed for carrying bulk material.

Semi-trailer Trailer vehicle without a front axle

A semi-trailer is a trailer without a front axle. In the United States, the term is also used to refer to the combination of a truck and a semi-trailer; a tractor-trailer.

Thrall Car Manufacturing Company was a manufacturer of railroad freight cars in Chicago Heights, Illinois from 1917 to 2001. The company was sold to Trinity Industries in 2001.

A specialized set of jargon describe the tools, equipment, and employment sectors used in the trucking industry in the United States. Some terms may be used within other English-speaking countries, or within the freight industry in general. For example, shore power is a term borrowed from shipping terminology, in which electrical power is transferred from shore to ship, instead of the ship relying upon idling its engines. Drawing power from land lines is more efficient than engine idling and eliminates localized air pollution. Another borrowed term is "landing gear", which refers to the legs which support the front end of a semi-trailer when it is not connected to a semi-truck. Some nicknames are obvious wordplay, such as "portable parking lot", in reference to a truck that carries automobiles.

Heyl & Patterson Inc. is an American specialist engineering company, founded in 1887 and based in Pittsburgh, Pennsylvania.

Open wagon Railway wagons for transportation of bulk goods

Open wagons form a large group of railway goods wagons designed primarily for the transportation of bulk goods that are not moisture-retentive and can usually be tipped, dumped or shovelled. The International Union of Railways (UIC) distinguishes between ordinary wagons and special wagons (F/6). Open wagons often form a significant part of a railway company's goods wagon fleet; for example, forming just under 40% of the Deutsche Bahn's total goods wagon stock in Germany.

Reliance Tipple United States historic place

The Reliance Tipple is the site of two coal tipples associated with coal production at Reliance, Wyoming. The first tipple was built in 1910 and used until 1936. The wood structure was built on a sandstone foundation and served Reliance Mines No. 1 through No. 6. The perishable portions of the earlier tipple have disappeared, leaving only the sandstone foundations and some artifacts buried in the tailings pile.

A Helix Dumper is a rail transport and unloading solution, designed for continuous rolling discharge of bulk commodities. Originally developed for the iron ore industry, the Helix Dumper system can handle many types of fine-grained and potentially sticky commodities. When the Helix Dumper wagon enters the unloading area, a wheel at the top of the wagon makes contact with the spiral-shaped rigid guide that constitutes the unloading station. As the wheel travels along the path of the guide, the wagon chassis remains on the rails while the body of the wagon is rotated 148 degrees to dump its load. After the rotation, the direction of the guide changes and the wagon body is returned to its normal position. The Helix Dumper has a discharge rate of up to 25,000 tonnes per hour.


  1. Timothy Long, Dumping apparatus for railway cars, U.S. Patent 527,117 , granted Oct. 9, 1894.
  2. Erskine Ramsay, Revolvable Car Dumping Structure, U.S. Patent 701,764 , granted June 3, 1902.
  3. Revolving Car Dump, Mines and Minerals, Vol. XXIX, No. 9 (April 1909); page 413.
  4. Car Dumper Equipment Company, The Mining Catalog (Metal and Quarry Ed.), Keystone, Pittsburgh, 1921; page 295.
  5. Cars, Freight: General Views, Car Builders' Cyclopedia of American Practice, Vol. 3; Figs. 21-23., see also the definition of drop-bottom on page 48.
  6. Spencer Otis, Drop Bottom Dump Car, U.S. Patent 780,762 , granted Jan. 24, 1905.
  7. Car-bodies, Freight: Goldola Cars, Car Builders' Cyclopedia of American Practice, Vol. 3; Figs. 21-23., see also the definition of hopper-bottom car on page 68.
  8. Halbert Powers Gillette, Chapter X: Methods and Cost with Cars, Earthwork and Its Cost, McGraw Hill, New York, 1920; pages 335-338 discuss side-dump cars.
  9. Les Benedict, director, The Last Pony Mine, part 2, Film Production Unit, Iowa State University, Ames, 1972; at 10:37 (2:12 in part 2), the film shows a mine car being dumped.
  10. International Correspondence Schools, The Elements of Mining Engineering Vol. 3, The Colliery Engineer Co., Scranton, 1900; pages 63-69, paragraphs 2644-2653.
  11. Patrick H. Kane, Car Loading and Unloading Device, U.S. Patent 305,600 , granted Sept. 23, 1884.
  12. William E. Hunt, Car Unloader, U.S. Patent 1,266,474 , issued May 14, 1918.
  13. A Mechanical Box Car Loader and Unloader, Railway Review, Vol. 68, No. 16 (April 16, 1921); pages 606-607.