Engineering:Hardtop

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Short description: Automobile roof
1965 Rambler Marlin, a pillarless hardtop

A hardtop is a rigid form of automobile roof, typically metal, and integral to the design, strength, and style of the vehicle.

In limited cases a hardtop roof can be detachable (often designed to store in the trunk), or retractable within the vehicle itself.

The pillarless hardtop (often referred to as simply "hardtop") is a body style of cars without a B-pillar.

Pillarless hardtop

1969 Australian Dodge Phoenix four-door sedan has a B-pillar and painted window frames
1969 Dodge DE Phoenix 400 pillarless hardtop coupe. The lack of a B-pillar and window frames, added vinyl roof, thickened C-pillar, and softened roofline creates an appearance similar to a convertible.
1976 Chrysler New Yorker with doors open. Note the absence of a driver's vent window, and half-height pillar to which the rear doors attach.
1963 Rambler American hardtop featured roof styling with crease lines to resemble convertible top bows

The pillarless hardtop (abbreviated as "hardtop") is a post-World War II car body designed with no center or B-pillar or glass frames.[1][2][3] If window glass frames are present, they are designed to retract with the window when lowered. This creates an impression of uninterrupted glass along the side of the car.[4] Even the smaller automakers like Packard introduced two door hardtops in 1952 "as a response to America's newly discovered fondness for sportier looking cars that resembled a convertible, but had the comfort and convenience of a two-door sedan."[5]

In one instance stylists added faux ribbing to a hardtop roof to make it appear to be like a convertible top,[6]

By the mid-1960s optional vinyl roofs became widely available in virtually all model lines, reinforcing the convertible look in hardtops.

A pillarless hardtop is inherently less rigid than a pillared body, requiring extra underbody strength to prevent shake. Production hardtops commonly share the frame or reinforced body structure of the contemporary convertible model, which is reinforced to compensate for the lack of a fixed roof. The hardtop design received criticism that its roof structure may not provide adequate protection in the event of a rollover crash.[7] However, subsequent research reported that rates of serious or fatal injury in hardtop models (both 2 and 4-door versions), as well as four-door station wagons, were significantly lower than sedans while the rates of any degree of injury for those same body styles were also significantly lower.[7] A 1980 study for evaluation of rollover test devices reported a greater degree of roof crush was associated with hardtop body styles, but the occurrence of severe passenger injury was not more frequent than in the other car body styles.[8]

The hardtop body style began to disappear along with convertibles in the mid-1970s, partly out of a concern that U.S. federal safety regulations would be difficult for pillarless models to pass. The ascendancy of monocoque construction also made the pillarless design less practical. Some models adopted modified roof styling, placing the B-pillars behind tinted side window glass and painting or molding the outer side of each pillar in black to make them less visible, creating a hardtop look without actually omitting the pillar. Some mid- to late-1970s models continued their previous two-door hardtop bodies, but with fixed rear windows or a variety of vinyl roof and opera window treatments.

By the end of the 1990s, almost all hardtop designs were discontinued as structural integrity standards continued to increase.

Hardtops were typically more expensive than regular sedan models when new. They are more collectible than standard models of the same vehicle which have a B-pillar.[9]

Origins

California Top on a 1926 Studebaker Special Six Phaeton

Early automobiles had no roof or sides, but by 1900 several cars were offered with fabric roofs and primitive folding tops.[10][11] However, cars with fully closed bodies (i.e. with a rigid roof and sides) grew in popularity and soon became the norm.[11]

In 1915–1918, the first pillarless hardtop cars were produced, then called "convertible cars" (or "touring sedans" or "Springfields").[12] The Springfield design featured folding upper frames on the doors and the rear glass frames are removable and stored under or behind the seats.[13] In the late teens, Cadillac offered a sedan with removable "B" pillars.

Another form of early pillarless hardtop is the "California top", originating in Los Angeles and most popular from 1917 to 1927.[12][14] These were designed to replace the folding roofs of touring cars, in order to enclose the sides of the car for better weather protection.[15] One objective of these aftermarket tops was to bring the cost of the closed car nearer to the prices of corresponding open cars.[16] Automobile dealers were encouraged to equip an open car with a California top to demonstrate that they were "cool and clean in summer, and warm and dry in winter."[17] The hard tops were frequently equipped with celluloid windows that retracted like a roller blind for open sided motoring offering a low-cost compromise between an open and closed car.[18]

United States

Two-door hardtop coupe:
1969 Pontiac Parisienne
Four-door hardtop sedan:
1966 Chrysler Newport
Two-door hardtop wagon:
1957 Mercury Commuter
Four-door hardtop wagon:
1958 Rambler Ambassador

There were a variety of hardtop-like body styles dating back to 1916.[19] Chrysler Corporation built seven pillarless Town and Country hardtop coupes as concept vehicles in 1946, and even included the body style in its advertising that year called the Town and Country Custom Club Coupe.[20][21] In 1951, Plymouth offered the Cranbrook Belvedere as a low priced hardtop two-door until 1953.[22]

Mass-production of hardtops began with General Motors, which launched two-door, pillarless hardtops in 1949 as the Buick Roadmaster Riviera, Oldsmobile 98 Holiday, and Cadillac Coupe de Ville. They were purportedly inspired by the wife of a Buick executive who always drove convertibles, but never lowered the top.

The Kaiser-Frazer 1949 Virginian was an early example of a four-door hardtop albeit with a removable thin, chrome- and-glass 'B' pillar held on by five screws.[23] The car was designed to have a convertible look and padded nylon or cotton was applied over the roof contributing to the soft-top appearance.[24]

Two-door hardtops became popular with consumers in the 1950s while the two-door sedan body design fell out of favor among buyers.[25]

In 1955, General Motors introduced the first four-door hardtops.[26][27] Following the pattern established by the two-door variants, GM utilized the same special sub-designations for the pillarless four-door body types within all their brands in North America. The term de Ville was used for Cadillac, Riviera was used for Buick, Holiday was used for Oldsmobile, Catalina was used for Pontiac, and Bel Air was used for Chevrolet.[28]

Other manufacturers also designated special names for their pillarless models. Ford called them Victoria, Chrysler used Newport and their luxury division Imperial used the name Southampton, Packard named them Mayfair, and Hudson's were Hollywoods. Nash used the Country Club moniker while pillarless Studebakers were Starliners, a name that was later used by Ford for its Galaxie hardtop.

By 1956 every major U.S. automaker offered two- and four-door hardtops in a particular model lineup. General Motors restyled their new models and now offered four-door hardtops from every division and in nearly every series except the lowest priced lines. Chrysler also offered two- and four-door hardtops for every brand, from Imperial, Chrysler, DeSoto, Dodge and Plymouth.[29]

In 1956, the first four-door hardtop station wagons were introduced to the Rambler line by American Motors Corporation.[30][31] The following year, the Mercury Commuter hardtop wagons became available in both two- and four-door body styles. Chrysler built four-door hardtop station wagons all the way through 1964, in both the Chrysler and Dodge 880 lines.

Throughout the 1960s the two-door pillarless hardtop was by far the most popular body style in most lines where such a model was offered. Even on family-type vehicles like the Chevrolet Impala, the two-door hardtop regularly outsold four-door sedans. Some car lines (such as the 1957-64 Cadillac and 1965–69 Corvair) only offered pillarless models with no sedans at all. So prevalent were true hardtops that Popular Mechanics had to describe that the new full-sized 1967 Oldsmobile Delmont models also included a "pillar" sedan.[32]

The U.S. industry's last pillarless two-door and four-door hardtops were in the 1978 Chrysler Newport and New Yorker lines.[33] Since then, no U.S. manufacturer has offered a true hardtop in regular production.

Europe

The Mercedes-Benz 300d was marketed as a "pillarless phaeton"
Two 1973 Sunbeam Rapiers: first with side windows lowered and raised on the second car

Various European manufacturers have produced hardtops without B-pillars (usually coupes), however, they are rarely marketed as pillarless hardtops. Examples include the current Bentley Continental GT, the 2008 Bentley Brooklands, the 2001-2003 Renault Avantime, the Rolls-Royce Wraith, and the 2012-2017 Ford B-Max. The 1958-1964 Facel Vega Excellence is one of few four-door hardtops produced in Europe.

German pillarless hardtops included cars from the Taunus brand which was a subbrand of Ford. Namely the Ford Taunus P5 and Ford P7 including both P7A and P7B versions. They had regular coupe versions with B pillars but the Hardtop Taunus models had no B pillar and when all the windows were rolled down, you got an open-air feel inside the car. The only german manufacturer that offered a pillarless twodoor, as well as wrap around windows in the back of the glasshouse from 1953 (3=6 F91) on and with a wrap around windscreen since 1959 (1000 Coupe) was DKW.

British pillarless hardtops included the Sunbeam Rapier and the Ford Consul Capri (355) which, unlike American models, sold fewer cars than their regular center pillar saloon versions.

A New Mini two-door sedan has been marketed as a hardtop in the United States, and is fully glazed on the exterior like one, which conceals a structural B-pillar on the inside which is disguised by a black border on the fixed rear windows.[34]

The Mercedes E-class coupe W213 from 2016 is an example of a modern pillarless design.

Japan

1972 Toyota Crown with side windows lowered

In July 1965 Toyota introduced Japan's first 2-door hardtop coupe, and August 1967 they installed the 1,587 cc DOHC 9R engine in the Toyota 1600GT. This followed with several manufacturers offering the popular bodystyle as a luxury car appearance. During the 1970s, Toyota produced the Toyota Crown in a pillarless two-door hardtop version.[35] Nissan followed suit with the Nissan Cedric and Nissan Gloria in 4-door sedan and 2-door hardtop body styles,[36] with the latter "rendered as a premium quality personal car."[37] Subaru introduced a new compact coupe as a genuine two-door hardtop with the Subaru Leone in 1971.[38] The pillarless hardtop models were more expensive and luxurious than the sedan versions.

In the 1980s, Toyota continued the design with the Mark II, Nissan with its Laurel, Mazda marketing its Luce and Subaru from 1989 until 2009 with their Legacy/Outback sedans and station wagons, albeit in variant with hidden B pillar which was discontinued in favour of traditional framed window design, dropping glass canopy styling Legacy wagons were known for.

Detachable hardtops

1959 Daimler SP250 with detachable hardtop

A detachable hardtop is a rigid, removable roof panel that is often stored in a car's trunk/boot.

Retractable hardtops

2005 Volvo C70 with retractable hardtop
Main page: Engineering:Retractable hardtop

A retractable hardtop (also known as coupé convertible or coupé cabriolet) is a type of convertible that forgoes a folding textile roof in favor of an automatically operated, multi-part, self-storing roof where the rigid roof sections are opaque, translucent, or independently operable.

References

  1. Flammang, James M. (1989). Standard Catalog of American Cars, 1976-1986. Krause Publications. pp. viii-ix. ISBN 978-0-87341-133-2. https://books.google.com/books?id=xTM2Ixfev5QC&q=Hardtop+cars+resembled+convertibles. Retrieved 1 April 2022. "Two-door hardtop: The term hardtop, as used for postwar cars up to the mid - 1970s, describes an automobile styled to resemble a convertible, but with a rigid metal (or fiberglass) top." 
  2. "Pillarless Pioneer: The 1949 Buick Roadmaster Riviera". 2 August 2011. https://ateupwithmotor.com/model-histories/buick-roadmaster-riviera-history/view-all/. 
  3. Gunnell, John (1982). Standard catalog of American cars, 1946-1975. Krause Publications. p. 15. ISBN 978-0-87341-027-4. https://books.google.com/books?id=joFTAAAAMAAJ&q=HARDTOP+car+styled+to+resemble+a+convertible,+but+having+a+rigid+top. 
  4. "Hardtop meaning". Engineering Dictionary. http://www.engineering-dictionary.org/Hardtop. 
  5. Mort, Norm (15 September 2010). American 'Independent' Automakers: AMC to Willys 1945 to 1960. Veloce Publishing. p. 25. ISBN 978-1-84584-239-0. https://books.google.com/books?id=yZo8GKToqqcC&dq=Hardtop+cars+resembled+convertibles&pg=PA25. Retrieved 1 April 2022. 
  6. Cranswick, Marc (22 December 2011). The Cars of American Motors: An Illustrated History. McFarland. p. 29. ISBN 978-0-7864-8570-3. https://books.google.com/books?id=r9j7MWLE_jMC&dq=Hardtop+cars+resembled+convertibles&pg=PA29. Retrieved 1 April 2022. "The '63 American pillarless hardtop, designed to resemble a convertible with its top up" 
  7. 7.0 7.1 Campbell, Bob J. (1970). "Driver Injury in Automobile Accidents Involving Certain Car Models". University of North Carolina Highway Safety Research Center. pp. 43–44. http://www.hsrc.unc.edu/research_library/PDFs/Driver70.ocr.pdf. 
  8. Segal, David J.; McGrath, Martin T. (1980). Analytical Study for Evaluation of Rollover Test Devices. Final Report. U.S. National Highway Traffic Safety Administration. p. 21. https://books.google.com/books?id=D-y_i0tuxygC&dq=Hardtop+body+style&pg=PA20. Retrieved 1 April 2022. 
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  12. 12.0 12.1 Howley, Tim (April 2006). "A History of Hardtops". Hemmings Classic Car. http://www.hemmings.com/hcc/stories/2006/04/01/hmn_feature14.html. Retrieved 9 February 2014. 
  13. Forbes, Kingston (1922). The principles of automobile body design, covering the fundamentals of open and closed passenger body design. Ware Bros.. pp. 245–249. https://archive.org/details/bub_gb_oqU7AAAAMAAJ. Retrieved 9 February 2014. "Springfield type construction has a folding upper frame on the doors stored under seat posts between." 
  14. "1925 Studebaker Big Six California Top". http://vintagecarheritage.com/1925-studebaker-big-six-california-top/. 
  15. "Glossary – A guide to speaking the language of CCCA". http://www.classiccarclub.org/info_garage/auto_facts_fun_history/glossary.html. 
  16. Cullen, T.F. (1 February 1922). "Price situation results in many improvements in cars". Automobile Trade Journal 25 (8): 28–29. https://books.google.com/books?id=6Qw0AQAAMAAJ&q=efforts+to+bring+the+price+of+the+closed+car+nearer+to+prices+of+corresponding+open+cars+California+tops+not+very+prominent+as+standard+equipment&pg=RA1-PA29. Retrieved 9 February 2014. 
  17. "A source of year 'round profit for dealers that sell Nash cars". Automobile Topics: 96. 25 February 1922. https://books.google.com/books?id=xShaAAAAYAAJ&q=is+cool+and+clean+in+summer,+and+warm+and+dry+in+winter.+Equip+an+open+demonstrating+car+with+one+of+these+handsome+tops&pg=PA96. Retrieved 9 February 2014. 
  18. Spajic, Igor (21 February 2012). "1925 Studebaker Big Six California Top". Vintage Car Heritage. http://www.vintagecarheritage.com/1925-studebaker-big-six-california-top/. 
  19. "Motoring Memories - Hardtop convertibles". http://autos.ca/articles/bv/hardtop-convertibles.htm. 
  20. "1946 Chrysler Town & Country Hardtop". 15 October 2007. http://auto.howstuffworks.com/1946-chrysler-town-and-country-hardtop.htm. 
  21. "1946 Chrysler Town and Country brochure". p. 4. http://www.lov2xlr8.no/brochures/chrysler/46tc/bilder/4.jpg. 
  22. John Gunnell, Standard Catalog of American Cars 1946-1975, Revised 4th Edition
  23. Marcus, Frank (June 2002). "1949 Kaiser Virginian". https://www.caranddriver.com/news/1949-kaiser-virginian-news. 
  24. "1950 Kaiser Virginian". 23 November 2007. https://auto.howstuffworks.com/1950-kaiser-virginian.htm. 
  25. Norbye, John P. (October 1965). "How Car Buying Has Changed in 20 Years". Popular Science 187 (4): 65. https://books.google.com/books?id=4SUDAAAAMBAJ&q=How+Car+Buying+Has+Changed+in+20+Years+emergence+of+hardtop+demise+two-door+sedan&pg=PA65. 
  26. Flory Jr., J. "Kelly" (2008). American Cars, 1946–1959: Every Model, Year by Year. McFarland. p. 621. ISBN 978-0-7864-5230-9. https://books.google.com/books?id=m-k3ONS880cC&q=1955+General+Motors+introduced+four-door+hardtops&pg=PA621. 
  27. "1955, The Hardtop Goes "Pillarless"". https://history.gmheritagecenter.com/wiki/index.php/1955,_The_Hardtop_Goes_%22Pillarless%22. 
  28. Niemeyer, Daniel (2013). 1950s American Style: A Reference Guide. Lulu. pp. 147, 148, 151. ISBN 978-1-304-20165-2. https://books.google.com/books?id=4q6fBQAAQBAJ&q=1955+General+Motors+introduced+four-door+hardtops&pg=PA149. 
  29. Flory Jr., J. "Kelly" (2008). American Cars, 1946–1959: Every Model, Year by Year. McFarland. p. 701. ISBN 978-0-7864-5230-9. https://books.google.com/books?id=m-k3ONS880cC&q=All+five+GM+divisions+restyled+their+new+models,+some+more+than+others+4-door+hardtop+models+were+now+available+from+every+division+and+in+nearly+every+series+except+the+lowest+priced+lines&pg=PA701. 
  30. "Rambler has everything new - even a hardtop wagon". Popular Mechanics 105 (1): 116–117. January 1956. https://books.google.com/books?id=uOEDAAAAMBAJ&pg=PA116. Retrieved 1 April 2022. 
  31. McGuire, Bill (21 December 2014). "A look at the hardtop station wagon". https://macsmotorcitygarage.com/a-look-at-the-hardtop-station-wagon/. 
  32. "the 67's: Solid citizens of Detroit". Popular Mechanics 126 (4): 114. October 1966. https://books.google.com/books?id=ydMDAAAAMBAJ&q=available+as+a+hardtop+sedan+and+coupe,+a+%22pillar%22+sedan+and+a+convertible+Ambassador+is+bigger+more+luxurious+for+1967&pg=PA114. 
  33. Flory Jr., J. Kelly (2012). American Cars, 1973-1980: Every Model, Year by Year. McFarland. p. 586. ISBN 978-0-7864-4352-9. https://books.google.com/books?id=PV1uzCfmJDgC&q=1978+Chryslers+the+last+American+true+pillarless+hardtop+models,+with+frameless+door+glass+and+fully+opening+windows+both+front+and+rear&pg=PA586. 
  34. "2015 Mini Hardtop 4-door: A stretch in size and appeal". https://www.kbb.com/car-news/all-the-latest/2015-mini-hardtop-4_door-a-stretch-in-size-and-appeal/2000010772/. 
  35. Classic Car: The Definitive Visual History. Penguin. 2016. p. 228. ISBN 978-1-4654-5907-7. https://books.google.com/books?id=cQjLDAAAQBAJ&q=Toyota+Crown+hardtop&pg=PA228. "Designed for the 1970s, the Crown followed US styling trends" 
  36. "Automotive History: Nissan Cedric – When The Pupil Becomes A Master". http://www.curbsideclassic.com/automotive-histories/curbside-classic-nissan-cedric-when-the-pupil-becomes-a-master/. 
  37. "Business Trends - Tokyo Report". Business Japan 36: 20. 1991. https://books.google.com/books?id=v5gSAQAAMAAJ&q=Cedric/Gloria+lineup+offers+a+choice+of+two+body+styles:+the+Hardtop,+rendered+as+a+premium+quality+personal+car. 
  38. "Subaru Leone Series was Reborn". Diamond's Economic Journal Industria 10: 40. 1980. https://books.google.com/books?id=T4YiAQAAMAAJ&q=Subaru+Leone+was+introduced+and+hardtop-type+cars+were+marketed+in+July.