Cab forward
Encyclopedia
The term cab forward refers to various rail
and road
vehicle
designs which place the driver's compartment substantially farther towards the front than is common practice.
design, a cab forward design will typically have the driver's compartment
(or cab
) placed immediately forward of the firebox at the very front of the engine while the fireman's station remains on the footplate behind the firebox (for obvious reasons). This type of design was widely, though not commonly, used throughout Europe in the first half of the 20th century, often in conjunction with an enclosed body design and/or streamlining
.
had several cab forward locomotives, 4-6-0
types group 670, 671 and 672. The 670 to 672 group engines had a 3 axle tender, the nickname was "mucca" (cow). The engines (construction year 1902, top speed 110 km/h) were used to haul passenger trains on the east coast line.
instead of coal
.
The cab forward design was widely used by the Southern Pacific Railroad, which developed it to deal with the peculiar problems of its routes. The 39 long tunnels and nearly 40 miles (64.4 km) of snow shed
s of the Sierra Nevada Mountains could funnel dangerous exhaust fumes back into the crew compartment of a conventional locomotive. After a number of crews nearly asphyxiated, someone had the idea of running his locomotive in reverse. This meant that the tender was leading the train, which introduced new problems. The tender blocked the view ahead and put crewmen on the wrong sides of the cab for seeing signals. The tenders were not designed to be pushed at the lead of the train, which limited speeds. Southern Pacific commissioned Baldwin Locomotive Works
to build a prototype cab-forward locomotive, then ordered more before the prototype had even arrived.
All of the cab-forwards were oil-burning locomotives, which meant there was little trouble involved putting the tender at what would normally be the front of the locomotive. The oil and water tanks were pressurized so that both would flow normally even on uphill grades. Visibility from the cab was superb, such that one crewman could easily survey both sides of the track. There were concerns about what would happen to the crew in the event of a collision, and at least one fatal accident occurred on the Modoc Line when a moving locomotive struck a flat car. Turning the normal locomotive arrangement around also placed the crew well ahead of the exhaust fumes, insulating them from that hazard. One problematic aspect of the design, however, was the routing of the oil lines; because the firebox was located ahead of the driving wheels (instead of behind them, the usual practice), oil leaks could cause the wheels to slip. A nuisance under most conditions, it resulted in at least one fatal accident. This occurred in 1941 when a cab-forward with leaking steam and oil lines entered the tunnel at Santa Susana Pass
near Los Angeles. The tunnel was on a grade, and as the slow-moving train ascended the tunnel, oil on the rails caused the wheels to slip and spin. The train slipped backwards and a coupler knuckle broke, separating the air line, causing an emergency brake application and stalling the train in a tunnel that was rapidly filling with exhaust fumes and steam. The oil dripping on the rails and ties then ignited beneath the engine cab, killing the crew.
No other North American railroad ordered cab-forward locomotives, although some, like the Western Pacific
, did consider the type. Built to deal with difficult terrain, these remarkable locomotives became an easily recognizable symbol of the Southern Pacific. One example of the type, Southern Pacific 4294
, is kept at the California State Railroad Museum
in Sacramento, California
. It is a 4-8-8-2
locomotive and is the only one to escape being scrapped.
The North Pacific Coast Railroad
, later part of the SP owned Northwestern Pacific company, rebuilt an 1875 4-4-0
into the first cab-forward locomotive. This innovative engine was built by William (Bill) Thomas, the NPC master mechanic who was nationally known and holder of a number of patents. Thomas used the running gear and frame from NPC locomotive 5, the "Bodega", which had been wrecked in 1897, to build NPC 21. With the addition a new and unusual marine boiler and an all-steel cab, installed in reverse order from standard engines, this unique creation earned Thomas a patent on the locomotive design. The 21 entered service in 1900, but only lasted a few years due to design flaws in the boiler. The crews were not happy with the new engine, finding it difficult to operate and scared of being on the front of the engine. They dubbed it "The Freak".
(4-6-4
) tank locomotive
had control cabs at both ends.
's ill-fated Leader is sometimes referred to as a cab-forward locomotive, but since it had a cab at each end like a typical modern diesel or electric locomotive this designation is not entirely appropriate.
The first modern mass produced
, U.S. automobile design using the cab forward concept was the Pacer
, introduced in 1975 by American Motors
(AMC). The company did not call it "cab forward", but the Pacer's layout included wheels pushed to the corners (short overhangs), a relatively wide body, and A-pillars
moved forward; the windshield was placed over part of the engine compartment. The cab forward design allowed the passenger area to be much larger than in other similar sized automobiles. The AMC Pacer contained many features, including the “cab forward” design, considered to be ahead of their time and did not enter mainstream automobiles until the 1990s.
In automobile
design, the term "cab forward" was used by Chrysler Corporation
starting in 1992 to refer to their new Lamborghini Portofino
inspired styling and engineering features, similar to those seen on the AMC Pacer, which improved cornering and interior space The passenger cabin was "pushed forward" so that the front wheelwell directly abutted the leading edge of the front doors, and the windshield extended forward near the front axle
, while the rear wheels were shifted towards the back corners of the vehicle. Moving the wheels to the edges allowed designers to enlarge the interior while improving ride and cornering. Numerous models built from 1993 to 2004 on the Chrysler LH platform
, the JA and JR platforms ("cloud cars")
, and the PL platform (Neon), were specifically marketed
as cab forward cars. Chrysler claimed to be the first to apply these features to a full-size car
.
In road vehicle design, Cab forward, also known as Cab-over, COE (Cab Over Engine), or forward control, is a body style of truck
or van
that has a vertical front or "flat face", with the cab
sitting above the front axle
. This truck configuration is currently common among Europe
an and Japan
ese truck manufacturers, because the laws governing overall vehicle lengths are strict and the body style allows longer trailers or a longer cargo area for the same overall length than a standard truck
(with an engine compartment ahead of a conventional cabin). Better visibility and maneuverability in tight quarters, such as for city delivery, is a benefit of locating the truck's cab up front. Large trucks of this type are most often described as cab over engine (COE) or cab over
models.
Rail transport
Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...
and road
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...
vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....
designs which place the driver's compartment substantially farther towards the front than is common practice.
Rail locomotives
In steam locomotiveSteam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
design, a cab forward design will typically have the driver's compartment
Cab (locomotive)
The cab, crew compartment or driver's compartment of a locomotive is the part of the locomotive housing the train driver or engineer, the fireman or driver's assistant , and the controls necessary for the locomotive's operation....
(or cab
Cab (locomotive)
The cab, crew compartment or driver's compartment of a locomotive is the part of the locomotive housing the train driver or engineer, the fireman or driver's assistant , and the controls necessary for the locomotive's operation....
) placed immediately forward of the firebox at the very front of the engine while the fireman's station remains on the footplate behind the firebox (for obvious reasons). This type of design was widely, though not commonly, used throughout Europe in the first half of the 20th century, often in conjunction with an enclosed body design and/or streamlining
Streamliner
A streamliner is a vehicle incorporating streamlining in a shape providing reduced air resistance. The term is applied to high-speed railway trainsets of the 1930s to 1950s, and to their successor "bullet trains". Less commonly, the term is applied to fully faired recumbent bicycles...
.
Italy: Ferrovie dello Stato italiane (FS)
The state owned Italian FSFerrovie dello Stato
Ferrovie dello Stato is a government-owned holding which manage infrastructure and service on the Italian rail network. The subsidiary Trenitalia is the main rail operator in Italy.-Organization:Ferrovie dello Stato subsidiaries are:...
had several cab forward locomotives, 4-6-0
4-6-0
Under the Whyte notation for the classification of steam locomotives, 4-6-0 represents the wheel arrangement of four leading wheels on two axles in a leading truck, six powered and coupled driving wheels on three axles, and no trailing wheels. This wheel arrangement became the second-most popular...
types group 670, 671 and 672. The 670 to 672 group engines had a 3 axle tender, the nickname was "mucca" (cow). The engines (construction year 1902, top speed 110 km/h) were used to haul passenger trains on the east coast line.
USA: Southern Pacific
In contrast however, the best known example of the cab-forward design in the United States, the Southern Pacific Cab-Forward (also known to a lesser extent as "Cab-in-fronts" and "Cab-aheads") placed the cab at the front by the simple expedient of turning the entire locomotive, minus the tender, by 180 degrees, an arrangement made possible by burning fuel oilFuel oil
Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash...
instead of coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
.
The cab forward design was widely used by the Southern Pacific Railroad, which developed it to deal with the peculiar problems of its routes. The 39 long tunnels and nearly 40 miles (64.4 km) of snow shed
Snow shed
An avalanche snow bridge or simply snow bridge is a type of rigid snow-supporting structure for avalanche control . Avalanche bridges can be made of steel, prestressed concrete frames, or timber....
s of the Sierra Nevada Mountains could funnel dangerous exhaust fumes back into the crew compartment of a conventional locomotive. After a number of crews nearly asphyxiated, someone had the idea of running his locomotive in reverse. This meant that the tender was leading the train, which introduced new problems. The tender blocked the view ahead and put crewmen on the wrong sides of the cab for seeing signals. The tenders were not designed to be pushed at the lead of the train, which limited speeds. Southern Pacific commissioned Baldwin Locomotive Works
Baldwin Locomotive Works
The Baldwin Locomotive Works was an American builder of railroad locomotives. It was located in Philadelphia, Pennsylvania, originally, and later in nearby Eddystone, Pennsylvania. Although the company was very successful as a producer of steam locomotives, its transition to the production of...
to build a prototype cab-forward locomotive, then ordered more before the prototype had even arrived.
All of the cab-forwards were oil-burning locomotives, which meant there was little trouble involved putting the tender at what would normally be the front of the locomotive. The oil and water tanks were pressurized so that both would flow normally even on uphill grades. Visibility from the cab was superb, such that one crewman could easily survey both sides of the track. There were concerns about what would happen to the crew in the event of a collision, and at least one fatal accident occurred on the Modoc Line when a moving locomotive struck a flat car. Turning the normal locomotive arrangement around also placed the crew well ahead of the exhaust fumes, insulating them from that hazard. One problematic aspect of the design, however, was the routing of the oil lines; because the firebox was located ahead of the driving wheels (instead of behind them, the usual practice), oil leaks could cause the wheels to slip. A nuisance under most conditions, it resulted in at least one fatal accident. This occurred in 1941 when a cab-forward with leaking steam and oil lines entered the tunnel at Santa Susana Pass
Santa Susana Pass
The Santa Susana Pass is a Southern California mountain pass in the Simi Hills connecting the San Fernando Valley and town of Chatsworth, to the Simi Valley and city of Simi Valley.-Natural history:...
near Los Angeles. The tunnel was on a grade, and as the slow-moving train ascended the tunnel, oil on the rails caused the wheels to slip and spin. The train slipped backwards and a coupler knuckle broke, separating the air line, causing an emergency brake application and stalling the train in a tunnel that was rapidly filling with exhaust fumes and steam. The oil dripping on the rails and ties then ignited beneath the engine cab, killing the crew.
No other North American railroad ordered cab-forward locomotives, although some, like the Western Pacific
Western Pacific Railroad
The Western Pacific Railroad was a Class I railroad in the United States. It was formed in 1903 as an attempt to break the near-monopoly the Southern Pacific Railroad had on rail service into northern California...
, did consider the type. Built to deal with difficult terrain, these remarkable locomotives became an easily recognizable symbol of the Southern Pacific. One example of the type, Southern Pacific 4294
Southern Pacific 4294
Southern Pacific 4294 was the last steam locomotive ordered new by Southern Pacific Railroad . It was built by Baldwin Locomotive Works in March 1944, and was used hauling SP's trains over the Sierra Nevada Mountains, often working on Donner Pass in California.- Construction and use :4294 was the...
, is kept at the California State Railroad Museum
California State Railroad Museum
The California State Railroad Museum is a museum in the state park system of California, USA, interpreting the role of the "iron horse" in connecting California to the rest of the nation. It is located in Old Sacramento at 111 I Street....
in Sacramento, California
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...
. It is a 4-8-8-2
4-8-8-2
Under the Whyte notation for the classification of steam locomotives, a 4-8-8-2 is a locomotive with four leading wheels, two sets of eight driving wheels, and a two-wheel trailing truck.Other equivalent classifications are:...
locomotive and is the only one to escape being scrapped.
The North Pacific Coast Railroad
North Pacific Coast Railroad
The North Pacific Coast Railroad was a common carrier narrow gauge steam railroad begun in 1874 and sold in 1902 to new owners who renamed it the North Shore Railroad and which rebuilt the southern section into a standard gauge electric railroad.The NPC operated in the northern California...
, later part of the SP owned Northwestern Pacific company, rebuilt an 1875 4-4-0
4-4-0
Under the Whyte notation for the classification of steam locomotives, 4-4-0 represents the wheel arrangement of four leading wheels on two axles , four powered and coupled driving wheels on two axles, and no trailing wheels...
into the first cab-forward locomotive. This innovative engine was built by William (Bill) Thomas, the NPC master mechanic who was nationally known and holder of a number of patents. Thomas used the running gear and frame from NPC locomotive 5, the "Bodega", which had been wrecked in 1897, to build NPC 21. With the addition a new and unusual marine boiler and an all-steel cab, installed in reverse order from standard engines, this unique creation earned Thomas a patent on the locomotive design. The 21 entered service in 1900, but only lasted a few years due to design flaws in the boiler. The crews were not happy with the new engine, finding it difficult to operate and scared of being on the front of the engine. They dubbed it "The Freak".
Prussia
Experimental Prussian T 16 (see in German) 2'C2'UIC classification of locomotive axle arrangements
The UIC classification of locomotive axle arrangements describes the wheel arrangement of locomotives, multiple units and trams. It is set out in the International Union of Railways "Leaflet 650 - Standard designation of axle arrangement on locomotives and multiple-unit sets". It is used in much...
(4-6-4
4-6-4
Under the Whyte notation for the classification of steam locomotives, 4-6-4 represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and four trailing wheels on two axles .Other equivalent classifications are:UIC classification:...
) tank locomotive
Tank locomotive
A tank locomotive or tank engine is a steam locomotive that carries its water in one or more on-board water tanks, instead of pulling it behind it in a tender. It will most likely also have some kind of bunker to hold the fuel. There are several different types of tank locomotive dependent upon...
had control cabs at both ends.
UK: Southern Railway
Oliver BulleidOliver Bulleid
Oliver Vaughan Snell Bulleid was a British railway and mechanical engineer best known as the Chief Mechanical Engineer of the Southern Railway between 1937 and the 1948 nationalisation, developing many well-known locomotives.- Early life and Great Northern Railway :He was born in Invercargill,...
's ill-fated Leader is sometimes referred to as a cab-forward locomotive, but since it had a cab at each end like a typical modern diesel or electric locomotive this designation is not entirely appropriate.
Automobiles
Mass production
Mass production is the production of large amounts of standardized products, including and especially on assembly lines...
, U.S. automobile design using the cab forward concept was the Pacer
AMC Pacer
The AMC Pacer is a two-door compact automobile produced in the United States by the American Motors Corporation between 1975 and 1980.Its initial design idea was started in 1971. The car's unusual rounded shape with massive glass area greatly contrasted with the three-box architecture with "square,...
, introduced in 1975 by American Motors
American Motors
American Motors Corporation was an American automobile company formed by the 1954 merger of Nash-Kelvinator Corporation and Hudson Motor Car Company. At the time, it was the largest corporate merger in U.S. history.George W...
(AMC). The company did not call it "cab forward", but the Pacer's layout included wheels pushed to the corners (short overhangs), a relatively wide body, and A-pillars
Pillar (car)
Pillars are the vertical supports of the greenhouse of an automobile — known respectively as the A, B, C or D-pillar moving in profile view from the front to rear....
moved forward; the windshield was placed over part of the engine compartment. The cab forward design allowed the passenger area to be much larger than in other similar sized automobiles. The AMC Pacer contained many features, including the “cab forward” design, considered to be ahead of their time and did not enter mainstream automobiles until the 1990s.
In automobile
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
design, the term "cab forward" was used by Chrysler Corporation
Chrysler
Chrysler Group LLC is a multinational automaker headquartered in Auburn Hills, Michigan, USA. Chrysler was first organized as the Chrysler Corporation in 1925....
starting in 1992 to refer to their new Lamborghini Portofino
Lamborghini Portofino
The Lamborghini Portofino was a concept car developed for Lamborghini by Kevin Verduyn, one of Chrysler's chief designers. Introduced at the 1987 Frankfurt Auto Show, it was a fully functional, four-door, four-seat sport sedan....
inspired styling and engineering features, similar to those seen on the AMC Pacer, which improved cornering and interior space The passenger cabin was "pushed forward" so that the front wheelwell directly abutted the leading edge of the front doors, and the windshield extended forward near the front axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...
, while the rear wheels were shifted towards the back corners of the vehicle. Moving the wheels to the edges allowed designers to enlarge the interior while improving ride and cornering. Numerous models built from 1993 to 2004 on the Chrysler LH platform
Chrysler LH platform
The LH platform served as the basis for the Chrysler Concorde, Chrysler LHS, Chrysler 300M, Dodge Intrepid, Eagle Vision, and the final Chrysler New Yorker. A Plymouth to be called the "Accolade" was planned, but never saw production...
, the JA and JR platforms ("cloud cars")
Chrysler JA platform
The JA platform was Chrysler's smaller complement to the LH cars which were larger than the K's, and a direct size replacement for the last extended K cars, the Acclaim and Spirit. It was a mid-size front-wheel drive automobile platform and was the basis for the Cloud Cars - the Chrysler...
, and the PL platform (Neon), were specifically marketed
Marketing
Marketing is the process used to determine what products or services may be of interest to customers, and the strategy to use in sales, communications and business development. It generates the strategy that underlies sales techniques, business communication, and business developments...
as cab forward cars. Chrysler claimed to be the first to apply these features to a full-size car
Full-size car
A full-size car is a marketing term used in North America for an automobile larger than a mid-size car. In the United States, the EPA uses "large car" to denote full-size cars....
.
Commercial vehicles
Truck
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
or van
Van
A van is a kind of vehicle used for transporting goods or groups of people.In British English usage, it can be either specially designed or based on a saloon or sedan car, the latter type often including derivatives with open backs...
that has a vertical front or "flat face", with the cab
Cabin (truck)
The cab of a truck is an enclosed space in a truck where the driver is seated. The word originated as a short form of cabriolet, not cabin. Some may refer to the tractor unit of a semi-trailer truck as a cab, but this is not the subject of this article...
sitting above the front axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...
. This truck configuration is currently common among Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
an and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese truck manufacturers, because the laws governing overall vehicle lengths are strict and the body style allows longer trailers or a longer cargo area for the same overall length than a standard truck
Truck
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
(with an engine compartment ahead of a conventional cabin). Better visibility and maneuverability in tight quarters, such as for city delivery, is a benefit of locating the truck's cab up front. Large trucks of this type are most often described as cab over engine (COE) or cab over
Cab over
Cab-over, also known as COE , cab forward, or forward control, is a body style of truck or van that has a vertical front or "flat face", with the cab of the truck sitting above the front axle...
models.