Backbone chassis
Encyclopedia
Chassis
A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
that is similar to the body-on-frame
Body-on-frame
Body-on-frame is an automobile construction method. Mounting a separate body to a rigid frame that supports the drivetrain was the original method of building automobiles, and its use continues to this day. The original frames were made of wood , but steel ladder frames became common in the 1930s...
design. Instead of a two-dimensional ladder type structure, it consists of a strong tubular backbone (usually rectangular in cross section
Cross section (geometry)
In geometry, a cross-section is the intersection of a figure in 2-dimensional space with a line, or of a body in 3-dimensional space with a plane, etc...
) that connects the front and rear suspension
Suspension (vehicle)
Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose — contributing to the car's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants...
attachment areas. A body is then placed on this structure.
It is almost a trademark design feature of Czech Tatra heavy trucks (cross-country, military etc.) - Hans Ledwinka
Hans Ledwinka
Hans Ledwinka was an Austrian automobile designer.- Youth :Ledwinka was born was born in Klosterneuburg , near Vienna, then part of the Austro-Hungarian Empire....
developed this style of chassis for Tatra 11
Tatra 11
The Tatra T11 was the first Tatra model to use the unique combination of major components that are still in use on the trucks produced by Tatra to this day.-Origins:...
in 1923 with the model Tatra 11
Tatra 11
The Tatra T11 was the first Tatra model to use the unique combination of major components that are still in use on the trucks produced by Tatra to this day.-Origins:...
. He further enhanced the design with 6x4 model Tatra 26
Tatra 26
The Tatra 26 is a vintage 6x4 automobile produced by the Czech manufacturer Tatra in the late 1920s and early 1930s. It was developed on the basis of the T 12. However, tests showed that the engine from T 12 did not have enough power, and it was replaced by the Tatra 30 engine...
which had excellent offroad abilities.
This type of chassis is also often found on some sports car
Sports car
A sports car is a small, usually two seat, two door automobile designed for high speed driving and maneuverability....
s. It also does not provide protection against side collision
Side collision
Side collisions are vehicle crashes where the side of one or more vehicles is impacted. These crashes often occur at intersections, in parking lots, when two vehicles pass on a multi-lane roadway, or when a vehicle hits a fixed object....
s, and has to be combined with a body that would compensate for this shortcoming.
Examples of cars using a backbone chassis include DeLorean DMC-12, Lloyd 600
Lloyd (car)
Norddeutsche Automobil und Motoren GmbH was a German brand created in 1908 and was owned by the Norddeutsche Lloyd shipping company. The factory was in Bremen...
, Lotus Elan
Lotus Elan
Lotus Elan is the name of two convertible cars and one fixed head coupé produced by Lotus Cars. The original Type 26, 26R Racing version , 36R Racing version , 36 Fixed Head Coupe, 45 Drop Head Coupe, and the "Type 50" +2 Coupe, circa 1962 to 1975, are commonly known as the '60s Elans...
, Lotus Esprit and Europa
Lotus Europa
The Lotus Europa was a two door mid-engined GT coupé built by Lotus Cars from 1966 to 1975. In 2006 Lotus began production of a totally new, Lotus Elise-derived design, a mid-engined GT coupé named Europa S....
, Škoda
Škoda Auto
Škoda Auto , more commonly known as Škoda, is an automobile manufacturer based in the Czech Republic. Škoda became a wholly owned subsidiary of the Volkswagen Group in 2000, positioned as the entry brand to the group...
420 Popular, Tatra T-87, Tatra T111
Tatra T111
The Tatra T111 was a truck produced in Czechoslovakia by the Tatra company.-History:The T111 was developed and manufactured during World War II as a heavy truck for use by the Wehrmacht. Production started in 1942 and continued for twenty years, ending in 1962 when it was replaced by the Tatra T138...
, Tatra T148
Tatra T148
The Tatra T148 was a truck produced in Czechoslovakia by the Tatra company.-History:In 1969 Tatra decided to modernize the existing T 138 model with a number of improvements and design changes. The new model series was designated T148...
, Tatra T815
Tatra T815
Tatra T815 is a truck family, produced by Czech company Tatra. It uses the traditional tatra concept of rigid backbone tube and swinging half-axles giving independent suspension. The vehicles are available in 4x4, 6x6, 8x8, 10x8, 10x10, 12x8 and 12x12 variants. There are both air-cooled and...
etc., as well as TVR S1
TVR S Series
The TVR S Series was announced at the 1986 NEC motor show. Due to a massive positive response the car went into production in less than 12 months, with 250 pre-manufacture orders...
. Some cars also use a backbone as a part of the chassis to strengthen it; examples include the Volkswagen Beetle
Volkswagen Beetle
The Volkswagen Type 1, widely known as the Volkswagen Beetle or Volkswagen Bug, is an economy car produced by the German auto maker Volkswagen from 1938 until 2003...
and the Locost
Locost
A Locost is a home-built clone of the Lotus Seven. The car features a space frame chassis usually welded together from mild steel square tubing. Front suspension is usually double wishbone with coil overs. The rear is traditionally live axle, but has many variants including independent rear...
where the transmission tunnel forms a backbone.
Advantages
- Standard conception truck's superstructure has to withstand the torsion twist and subsequent wear reduces vehicle's lifespan.
- The half-axles have better contact with ground when operated off the road. This has little importance on roads.
- The vulnerable parts of drive shaft are covered by thick tube. The whole system is extremely reliable, however if a problem occurs, repairs are more complicated.
- Modular system is enabling configurations of 2, 3, 4, 5, or 6-axle vehicles with various wheel bases.
Disadvantages
- Manufacturing the backbone chassis is more complicated and more costly. However the more axles with all wheel drive are needed, the cost benefit turns in favor of backbone chassis.
- The backbone chassis is heavier for a given torsional stiffness than a uni-body.
See also
- Tatra concept
- Frame (vehicle)Frame (vehicle)A frame is the main structure of the chassis of a motor vehicle. All other components fasten to it; a term for this is design is body-on-frame construction.In 1920, every motor vehicle other than a few cars based on motorcycles had a frame...
- Body-on-frameBody-on-frameBody-on-frame is an automobile construction method. Mounting a separate body to a rigid frame that supports the drivetrain was the original method of building automobiles, and its use continues to this day. The original frames were made of wood , but steel ladder frames became common in the 1930s...
- ChassisChassisA chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
- CoachworkCoachworkCoachwork is the body of a horse-drawn coach or carriage, a motor vehicle , a railroad car or railway carriage. Usually reserved for bodies built on a separate chassis, rather than being of unitary or monocoque construction...
- MonocoqueMonocoqueMonocoque is a construction technique that supports structural load by using an object's external skin, as opposed to using an internal frame or truss that is then covered with a non-load-bearing skin or coachwork...
- Spaceframe
- SubframeSubframeA subframe is a structural component of a vehicle, such as an automobile or an aircraft, that uses a discrete, separate structure within a larger body-on-frame or unit body to carry certain components, such as the engine, drivetrain, or suspension. The subframe is bolted and/or welded to the vehicle...
- SuperleggeraSuperleggeraSuperleggera is an automobile chassis construction technology developed by Felice Bianchi Anderloni of Italian coachbuilder Carrozzeria Touring. The company was located just north of Milan, near Alfa Romeo, Italian Citroen, and the former Isotta-Fraschini plant...
- Swing axleSwing axleA swing axle is a simple type of independent suspension first used in early aircraft , such as the Sopwith and Fokker, usually with rubber bungee and no damping....
External links
- Comparison of standard ladder chassis and backbone chassis with half axles on offroad testing track with emphasis on the twist of superstructure (video):
- Ladder chassis (Renault fire engine)
- Backbone chassis (Tatra T815 fire engine)