A well car, also known as a double-stack car (or also intermodal car/container car), is a type of

railroad car A railroad car, railcar (American and Canadian English), railway wagon, railway carriage, railway truck, railwagon, railcarriage or railtruck (British English and UIC), also called a train car, train wagon, train carriage or train truck, is a ...

specially designed to carry

intermodal container An intermodal container, often called a shipping container, is a large standardized shipping container, designed and built for intermodal freight transport, meaning these containers can be used across different Mode of transport, modes of trans ...

s (shipping containers) used in

intermodal freight transport Intermodal freight transport involves the transportation of freight in an intermodal container or vehicle, using multiple modes of transportation (e.g., rail, ship, aircraft, and truck), without any handling of the freight itself when changing ...

. The "well" is a depressed section which sits close to the rails between the wheel trucks of the car, allowing a container to be carried lower than on a traditional

flatcar A flatcar (US) (also flat car, or flatbed) is a piece of rolling stock that consists of an open, flat deck mounted on a pair of trucks (US) or bogies (UK), one at each end containing four or six wheels. Occasionally, flat cars designed to carry ...

. This makes it possible to carry a stack of two containers per unit on railway lines (

double-stack rail transport Double-stack rail transport is a form of intermodal freight transport in which railroad cars carry two layers of intermodal containers. Invented in the United States in 1984, it is now being used for nearly seventy percent of United States inter ...

) wherever the

structure gauge A structure gauge, also called the minimum clearance outline, is a diagram or physical structure that sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. It specifies the height and width of pl ...

assures sufficient clearance. The top container is secured to the bottom container either by a bulkhead built into the car (e.g., bottom and top containers are the same dimensions of 40 ft.), or through the use of

inter-box connector A twistlock or twist lock, together with matching corner castings, as defined in norms including ISO 1161:1984, form a standardized (rotating) connector system, for connecting and securing intermodal, and predominantly ISO-standard internatio ...

s (IBC). Four IBCs are needed per wellcar. In the process of an inbound train becoming an outbound train, there are four processes: unlock to unload the top container of inbound train, remove then unload bottom container, insert after loading bottom container of outbound train, lock after top container loaded. Advantages to using well cars include increased stability due to the lower

center of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weight function, weighted relative position (vector), position of the distributed mass sums to zero. Thi ...

of the load, lower

tare weight Tare weight , sometimes called unladen weight, is the weight of an empty vehicle or container. By subtracting tare weight from gross weight ( laden weight), one can determine the weight of the goods carried or contained (the net weight). Etymol ...

, and in the case of articulated units, reduced

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 oft ...

. Well cars are most common in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

where intermodal traffic is heavy and

electrification Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source. The broad meaning of the term, such as in the history of technology, economic histor ...

is less widespread; thus overhead clearances are typically more manageable. In India double stacking of containers is done on

s under high catenary because the wider gauge permits more height while keeping the centre of gravity still low.

History

Southern Pacific Railroad The Southern Pacific (or Espee from the railroad initials- SP) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the ...

(SP), along with

Malcom McLean Malcolm Purcell McLean (November 14, 1913 – May 25, 2001; later known as Malcom McLean) was an American businessman. He was a transport entrepreneur who invented the modern intermodal shipping container, which revolutionized transport and inte ...

, devised the first double-stack intermodal car in 1977.Cudahy, Brian J., -
"The Containership Revolution: Malcom McLean's 1956 Innovation Goes Global"
- ''TR News''. - (c/o National Academy of Sciences). - Number 246. - September–October 2006. - (Adobe Acrobat *.PDF document) SP then designed the first car with

ACF Industries ACF Industries, originally the American Car and Foundry Company (abbreviated as ACF), is an American manufacturer of railroad rolling stock. One of its subsidiaries was once (1925–54) a manufacturer of motor coaches and trolley coaches und ...

that same year. At first it was slow to become an industry standard, then in 1984

American President Lines APL, formerly called American President Lines Ltd., is an American container shipping company that is a subsidiary of French shipping company CMA CGM. It operates an all-container ship fleet, including 9 U.S. flagged container vessels. In 1938, ...

started working with the Thrall Company to develop a refined well car and with the Union Pacific to operate a train service using the new well cars. That same year, the first all "double stack" train left

Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world' ...

for

South Kearny, New Jersey South Kearny, also known as Kearny Point, is an industrial district and distinct area of the western part of Hudson County, New Jersey at the northern end of Newark Bay in the town of Kearny, New Jersey. It is on the larger peninsula once calle ...

, under the name of "Stacktrain" rail service. Along the way the train transferred from the UP to CNW and then to

Conrail Conrail , formally the Consolidated Rail Corporation, was the primary Class I railroad in the Northeastern United States between 1976 and 1999. The trade name Conrail is a portmanteau based on the company's legal name. It continues to do busin ...

Multiple unit cars

Each unit of a double-stack car is constructed with a single well, but are often constructed with multiple units of three to five units, connected by

articulated An articulated vehicle is a vehicle which has a permanent or semi-permanent pivot joint in its construction, allowing it to turn more sharply. There are many kinds, from heavy equipment to buses, trams and trains. Steam locomotives were someti ...

connectors. Articulated connectors are supported by the centerplate of a single truck, (often a 125-short-ton, 112-long-ton or 113-tonne capacity truck but sometimes a 150-short-ton, 134-long-ton or 136-tonne capacity one). Also, in a number of cases, multiple single-well cars (usually 3 or 5) are connected by

drawbars The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Multiple models have been produced, most of which use sliding drawbars to vary sounds. Until 1975, Hammond organs generated s ...

and share a single

reporting mark A reporting mark is a code used to identify owners or lessees of rolling stock and other equipment used on certain rail transport networks. The code typically reflects the name or identifying number of the owner, lessee, or operator of the equip ...

. 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 starting from the "B" unit and increasing towards the "A" unit.

Carrying capacity

Double-stack wellcars come in a number of sizes, related to the standard sizes of the

containers A container is any receptacle or enclosure for holding a product used in storage, packaging, and transportation, including shipping. Things kept inside of a container are protected on several sides by being inside of its structure. The term ...

they are designed to carry. Well lengths of , and are most common. A number of wells and 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.) On 40 ft, 45 ft, 48 ft, or 53 ft cars, larger containers (45 ft or up) are often placed on top of smaller containers that fit in the available wells to efficiently use all available space. All wells are also capable of carrying two 20 ft ISO containers in the bottom position. Some double-stack well cars have been also equipped with hitches which allow them to carry

semi-trailer 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. A large proportion of a semi-trailer's weight is supported by a tracto ...

s as well as containers. These are known as "all-purpose" well cars. Articulated well cars typically have a capacity of per well. As highway weight limits in the US restrict most containers to less than this is adequate for two containers stacked. Some single well cars have capacity for two fully loaded containers.

Econo Stack or Twin Stack well car

Econo Stack well cars are a variation of conventional well cars and their main purpose is to give the double stacked containers more support. The down side to them is they do not allow 53-foot containers to be stacked on top, but 45-foot containers still fit and are able to be stacked on top.

Gallery

File:Freight train in Tucson Arizona 2.JPG, A train of well cars in Arizona carrying double-stacked containers. File:WellCarWithTruckTrailerHitchCanadianPacificTrainBoltonON.jpg, A 53-foot well car also fitted with a

fifth-wheel coupling The fifth-wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly. The coupling consists of a kingpin, a vertical steel pin protruding from the bottom of the front of the semi-tr ...

at each end to allow

transport as well. File:Gabarit AAR Plate-H.png, AAR Plate-H

loading gauge A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and ke ...

File:Freight train in Jacksonville, FL.jpg, A container train passing through

Jacksonville Jacksonville is a city located on the Atlantic coast of northeast Florida, the most populous city proper in the state and is the List of United States cities by area, largest city by area in the contiguous United States as of 2020. It is the co ...

, Florida, with 53' containers used for shipments within North America. File:Intermodal shipping containers on a railway flat car.jpg, A well car loaded with two forty foot containers of Transportación marítima mexicana (TMM).

Usage

* – double stack trains operate between

Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...

Adelaide Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...

, Darwin and

Parkes, NSW Parkes is a town in the Central West region of New South Wales, Australia. It is the main settlement in the local government area of Parkes Shire. Parkes had a population of 11,224 as at 30 June 2018. Estimated resident population, 30 June 2 ...

with clearances. , the

Inland Railway Inland Rail, also known as Inland Railway and previously Australian Inland Railway Expressway, is a railway line under construction in Australia. Once complete, it will connect the ports of Melbourne and Brisbane along a new route west of th ...

between Melbourne and Brisbane was being be built for operation of double stacked trains using wellcars. * – using double stacked container trains under

25 kV AC Railway electrification systems using alternating current (AC) at are used worldwide, especially for high-speed rail. It is usually supplied at the standard utility frequency (typically 50 or 60Hz), which simplifies traction substations. The d ...

overhead line An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipmen ...

sBusiness Line India Double Stacking
/ref> using X2H and X2K type wellcars manufactured by

CRRC CRRC Corporation Limited (known as CRRC) is a Chinese state-owned and publicly traded rolling stock manufacturer. It is the world's largest rolling stock manufacturer in terms of revenue, eclipsing its major competitors of Alstom and Siemens. It ...

. Initial tests where done with a standard container and a reduced height container on top, later increasing to a high hi-cube and a standard container on top. Even after increasing the height of the overhead wire it is not possible to use a stack of two hi-cube containers on the lines under electrification, even in well cars. * – The Mombasa-Nairobi standard gauge railway operates double-stacked trains using X2K type wellcars manufactured by

, the first such trains being launched on October 1, 2018. * – the

Panama Canal Railway The Panama Canal Railway ( es, Ferrocarril de Panamá) is a railway line linking the Atlantic Ocean to the Pacific Ocean in Central America. The route stretches across the Isthmus of Panama from Colón (Atlantic) to Balboa (Pacific, near P ...

runs double stack trains using well cars manufactured by

Gunderson Inc. Gunderson may refer to: People Gunderson is a surname of Norwegian and Swedish origin. Notable people with the surname include: *Lance Armstrong (born Lance Edward Gunderson; 1971), American cyclist *Carl Gunderson (1864–1933), American politi ...

* –

Saudi Railways Organization The Saudi Railways Organization (SRO) ( ar, المؤسسة العامة للخطوط الحديدية) is one of two state-owned companies that operates Saudi Arabia's rail network along with Saudi Railway Company. The SRO operates a network of ra ...

line to

Dammam Dammam ( ar, الدمّام ') is the fifth-most populous city in Saudi Arabia after Riyadh, Jeddah, Mecca, and Medina. It is the capital of the Eastern Province. With a total population of 1,252,523 as of 2020. The judicial and administrative ...

. * – The small

s and consequently small loading gauges on

British railways British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...

mean that intermodal well wagons are required to be able to transport high

s on routes where the loading gauge is W9 or smaller.

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 railroad In the United States, railroad carriers are designated as Class I, II, or III, according to annual revenue criteria originally set by the Surface Transportation Board in 1992. With annual adjustments for inflation, the 2019 thresholds were US$ ...

companies in the U.S. have initiated improvement programs to remove obstructions to double-stack trains. Examples include the

Heartland Corridor The Heartland Corridor is a public-private partnership between the Norfolk Southern Railway (NS) and the Federal Highway Administration and three U.S. states to improve railroad freight operations. The $150 million plan was developed to fa ...

(

Norfolk Southern Railway The Norfolk Southern Railway is a Class I freight railroad in the United States formed in 1982 with the merger of Norfolk and Western Railway and Southern Railway. With headquarters in Atlanta, the company operates 19,420 route miles (31 ...

) and

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 Midw ...

(

CSX Transportation CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. The railroad operates approximately 21,000 route miles () of track. ...

References

Online rosters

Double Stack Cars
- A list of double stack cars by reporting mark, with various data
RR Rolling Stock 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'': :: 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'': :: 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.

External links

* http://people.hofstra.edu/geotrans/eng/ch3en/conc3en/pbdblstk.html The here mentioned is too low, it is more like

* ttps://web.archive.org/web/20100205090613/http://www.time.com/time/magazine/article/0,9171,806900,00.html A Partnership of Two Old Rivals ''Time Magazine'', June 7, 1954
Guide to Rail Cars

Association of American Railroads Mechanical Division, page 238

Greenbrier 53’ All-Purpose double-stack well car
{{Intermodal containers Freight rolling stock Intermodal containers