Double-stack car
Encyclopedia
Intermodal container
An intermodal container is a standardized reusable steel box used for the safe, efficient and secure storage and movement of materials and products within a global containerized intermodal freight transport system...
s (shipping containers) used in intermodal freight transport
Intermodal freight transport
Intermodal freight transport involves the transportation of freight in an intermodal container or vehicle, using multiple modes of transportation , without any handling of the freight itself when changing modes. The method reduces cargo handling, and so improves security, reduces damages and...
. The "well" is a depressed section which sits close to the rails between the wheel trucks
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
of the car, allowing a container to be carried lower than on a traditional flatcar
Flatcar
A flatcar is a piece of railroad or railway rolling stock that consists of an open, flat deck on four or six wheels or a pair of trucks or bogies . The deck of the car can be wood or steel, and the sides of the deck can include pockets for stakes or tie-down points to secure loads...
. This makes it possible to carry a stack of two containers per unit on railway lines (double-stack rail transport
Double-stack rail transport
Double-stack rail transport is a form of Intermodal freight transport where intermodal containers are stacked two high on railroad cars. Introduced in North America in 1984, double stack has become increasingly common, being used for nearly 70% of United States intermodal shipments...
) wherever the loading gauge
Loading gauge
A loading gauge defines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges, tunnels and other structures...
assures sufficient clearance. The top container is held in place either by a bulkhead built into the car, or through the use of inter-box connectors.
Advantages to using well cars include increased stability due to the lower center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...
of the load, lower tare weight
Tare weight
Tare , from the Middle French word tare "wastage in goods, deficiency, imperfection" , from Italian tara, from Arabic tarah, lit. "thing deducted or rejected," from taraha "to reject" weight, sometimes called unladen weight, is the weight of an empty vehicle or container...
, and in the case of articulated units, reduced slack action
Slack action
In railroading, slack action is the amount of free movement of one car before it transmits its motion to an adjoining coupled car. This free movement results from the fact that in railroad practice cars are loosely coupled, and the coupling is often combined with a shock-absorbing device, a "draft...
.
Double-stack cars are most common in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
where intermodal traffic is heavy and electrification
Railway electrification system
A railway electrification system supplies electrical energy to railway locomotives and multiple units as well as trams so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world...
is less widespread; thus overhead clearances are typically more manageable.
History
Southern Pacific RailroadSouthern Pacific Railroad
The Southern Pacific Transportation Company , earlier Southern Pacific Railroad and Southern Pacific Company, and usually simply called the Southern Pacific or Espee, was an American railroad....
(SP), along with Malcom McLean
Malcom McLean
Malcom Purcell McLean , born in Maxton, North Carolina, was an American entrepreneur, often called "the father of containerization"...
, came up with the idea of the first double-stack intermodal car in 1977. SP then designed the first car with ACF Industries
American Car and Foundry Company
American Car and Foundry is a manufacturer of railroad rolling stock. One of its subsidiaries was once a manufacturer of motor coaches and trolley coaches under the brand names of ACF and ACF-Brill. Today ACF is known as ACF Industries LLC and is based in St. Charles, Missouri...
that same year. At first it was slow to become an industry standard, then in 1984 American President Lines
American President Lines
American President Lines Ltd. is the world's seventh-largest container transportation and shipping company, providing services to more than 140 countries through a network combining intermodal freight transport operations with IT and e-commerce...
, started working with the SP and that same year, the first all "double stack" train left Los Angeles, California
Los Angeles, California
Los Angeles , with a population at the 2010 United States Census of 3,792,621, is the most populous city in California, USA and the second most populous in the United States, after New York City. It has an area of , and is located in Southern California...
for South Kearny, New Jersey
South Kearny, New Jersey
South Kearny is an industrial district and distinct area of Hudson County, New Jersey at the northern end of Newark Bay in the town of Kearny, New Jersey. It is on larger peninisula once called New Barbadoes Neck, which also include the other Kearny districts of the Uplands and the Kearny Meadows...
, under the name of "Stacktrain" rail service. Along the way the train transferred from the SP to Conrail
Consolidated Rail Corporation
The Consolidated Rail Corporation, commonly known as Conrail , was the primary Class I railroad in the Northeast U.S. between 1976 and 1999. The federal government created it to take over the potentially profitable lines of bankrupt carriers, including the Penn Central Transportation Company and...
.
Multiple unit cars
Also, in a number of cases, multiple single-well cars (usually 3 or 5) are connected by drawbars and share a single reporting mark
Reporting mark
A reporting mark is a two-, three-, or four-letter alphabetic code used to identify owners or lessees of rolling stock and other equipment used on the North American railroad network. The marks are stenciled on each piece of equipment, along with a one-to-six-digit number, which together uniquely...
.
On both types of multiple-unit cars, the units are typically distinguished by letters, with the unit on one end being the "A" unit, and the unit on the other end being the "B" unit. Middle units are labeled starting with "C", and going up to "E" for five-unit cars.
Carrying capacity
Double-stack cars come in a number of sizes, related to the standard sizes of the containersIntermodal container
An intermodal container is a standardized reusable steel box used for the safe, efficient and secure storage and movement of materials and products within a global containerized intermodal freight transport system...
they are designed to carry. Well lengths of 40 ft (12.19 m), 48 ft (14.63 m) and 53 ft (16.15 m) are most common. A number of 45 ft (13.72 m) wells and 56 ft (17.07 m) wells also exist. (The sizes of wells are frequently marked in large letters on the sides of cars to assist yard workers in locating suitable equipment for freight loads.)
In cases where wells are smaller than some of the containers being loaded, larger containers are often placed on top of smaller containers that fit in the available wells. Many wells are also capable of carrying two 20 ft ISO containers in the bottom position.
Some double-stack cars have been also equipped with hitches
Fifth wheel coupling
The fifth wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly. Some recreational vehicles use a fifth wheel configuration, requiring the coupling to be installed in the bed of a pickup truck as a towing vehicle...
which allow them to carry semi-trailer
Semi-trailer
A semi-trailer is a trailer without a front axle. A large proportion of its weight is supported by a road tractor, a detachable front axle assembly known as a dolly, or the tail of another trailer...
s as well as containers. These are known as "all-purpose" well cars.
Other countries
AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
- double stack trains operate between Perth
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
, Adelaide
Adelaide
Adelaide is the capital city of South Australia and the fifth-largest city in Australia. Adelaide has an estimated population of more than 1.2 million...
, Darwin
Darwin, Northern Territory
Darwin is the capital city of the Northern Territory, Australia. Situated on the Timor Sea, Darwin has a population of 127,500, making it by far the largest and most populated city in the sparsely populated Northern Territory, but the least populous of all Australia's capital cities...
and Parkes, NSW 6.5 m (21 ft) clearances India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
- Mundra Port
Mundra Port
Mundra Port and Special Economic Zone Limited manages the largest privately owned port in the country. The port project was initiated in 1988 by the Adani Group as a logistics base for their international trade operations when the sector was opened for private sector...
operates double stack diesel trains on gauge using flatcar
Flatcar
A flatcar is a piece of railroad or railway rolling stock that consists of an open, flat deck on four or six wheels or a pair of trucks or bogies . The deck of the car can be wood or steel, and the sides of the deck can include pockets for stakes or tie-down points to secure loads...
s. It is one of only 3 countries to commercially double stack 9 in 6 in (2.9 m) tall containers on a train. Experiments for double stacking under 25 kV AC overhead lines
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
have begun because of funds given by Japan. China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
- using double stacked container trains under 25 kV AC overhead lines
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
. Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
- The small structure gauge
Structure gauge
The structure gauge, also called the minimum clearance outline, is the minimum height and width of tunnels and bridges as well as the minimum height and width of the doors that allow a rail siding access into a warehouse...
s and consequently small loading gauges on the British Railways mean that double stacking is not possible and that well cars are required to be able to transport 9 in 6 in (2.9 m) high intermodal container
Intermodal container
An intermodal container is a standardized reusable steel box used for the safe, efficient and secure storage and movement of materials and products within a global containerized intermodal freight transport system...
s.
Choke points
Low bridges and narrow tunnels in various locations prevent the operation of double-stack trains until costly upgrades are made. Some Class I railroadClass I railroad
A Class I railroad in the United States and Mexico, or a Class I rail carrier in Canada, is a large freight railroad company, as classified based on operating revenue.Smaller railroads are classified as Class II and Class III...
companies in the U.S. have recently initiated improvement programs to remove obstructions to double-stack trains. See Heartland Corridor
Heartland Corridor
The Heartland Corridor is a public-private partnership between the Norfolk Southern Railway and the Federal Highway Administration and three US states to improve railroad freight operations....
(Norfolk Southern Railway
Norfolk Southern Railway
The Norfolk Southern Railway is a Class I railroad in the United States, owned by the Norfolk Southern Corporation. With headquarters in Norfolk, Virginia, the company operates 21,500 route miles in 22 eastern states, the District of Columbia and the province of Ontario, Canada...
) and National Gateway
National Gateway
National Gateway is a multi-stage railroad construction project in the United States promoted by CSX Transportation, a unit of CSX Corporation. It is designed to improve rail connections between ports in the U.S. mid-Atlantic seaboard and the Midwest by upgrading bridges and tunnels to allow taller...
(CSX Transportation
CSX Transportation
CSX Transportation operates a Class I railroad in the United States known as the CSX Railroad. It is the main subsidiary of the CSX Corporation. The company is headquartered in Jacksonville, Florida, and owns approximately 21,000 route miles...
).
Online rosters
- Double Stack Cars - A list of double stack cars by reporting mark, with various data
- RR Rolling Stock Category: Double Stack Car - Picture Archives
Magazine articles
- Mainline Modeler:
-
- Fortenberry, Curt & Bill McKean. - "APL Container Car". - February 1987. - p.65-69.
- Fortenberry, Curt & Robert L. Hundman. - "APL container car part II the brake system". - March 1987. - p.78-81.
- Hundman, Robert L., & Curt Fortenberry. - "APL 45-foot container car". - May 1987. - p.54-57.
- Model Railroader:
-
- Durrenberger, Cyril. - "SP/ACF double stack cars". - October 1983. - p.83-93.
- Model Railroading:
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- Bontrager, David A. - "Articulated double stacks: a prototype overview". - June 1993. p.24-29.
- Bontrager, David A. - "The Newest Prototype Well Cars: An Abundance of Kitbashing Possibilities". August 1997. - p.46-49.
- Casdorph, David G. and Ed McCaslin. - "Gunderson's Husky-Stack: The Prototype and Detailing A-Line's HO Model". - October 1995. - p.32-37.
- Casdorph, David G. - "NSC 53' Drawbarred Well Car Roster and Pictorial". - August 2002. - p.30-33
- Geiger, Doug. - "Thrall Double-Stacks: Three-Well DTTX Drawbar-Connected Car". - October 1994. - p.50-55.
- Geiger, Doug. - "Gunderson Husky Stack Three-Well BN Drawbar-Connected Car". - July 1995. - p.48-53.
- Geiger, Doug. - "Gunderson Maxi-Stack IIIs Part I: The Prototype". - December 1995. - p.58-63.
- Geiger, Doug. - "Maxi-Stack Well Car Part I: The Prototype". - April 1997. - p.28-31.
- Mansfield, Jim. - "Thrall Five-Unit Double-Stack Car - Series TWG50J". - October 1993. - p.19-23.
- Mansfield, Jim. - "Thrall Five-Unit Double-Stack Car - Series APLX 5000". - November 1993. - p.24-25, 27-31.
- Railroad Model Craftsman:
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- Panza, Jim & Chuck Yungkurth. - "Thrall's double-stack cars". - January 1989. - p.89-98.
- Panza, Jim & Bruce Keating. - "The Gunderson Husky-Stack well car". - July 1992. - p.71-75.
- Panza, Jim & William Halliar. - "Thrall stand-alone and drawbar connected well cars". - October 1992. - p.64-68.