Bubbletop

Bubbletop (pronounced buhb-uhl-top)

(1) In aircraft design, a design of pilot’s canopy (originally military slang for what designers dubbed the “bubble canopy”, a Perspex molding which afforded exceptional outward visibility).

(2) An automobile using a transparent structure over the passenger compartment, replacing the usual combination of roof & windows.

(3) A descriptor of certain automobiles (as "Bubble Top") of the early 1960s, based on the shape rather than the method of construction, conventional metal and glass used.

1940s: The construct was bubble +‎ top.  Bubble dates from the late fourteenth century and was from the Middle English noun bobel which may have been from the Middle Dutch bubbel & bobbel and/or the Low German bubbel (bubble) and Middle Low German verb bubbele, all thought to be of echoic origin.  The related forms include the Swedish bubbla (bubble), the Danish boble (bubble) and the Dutch bobble.  Top pre-dates 1000 and was from the Middle English top, toppe & tope (top, highest part; summit; crest; tassel, tuft; (spinning) top, ball; a tuft or ball at the highest point of anything), and the Old English top & toppa (top, summit, tuft of hair), from the Proto-West Germanic topp, from the Proto-Germanic tuppaz (braid, pigtail, end), of unknown origin.  It was cognate with the Old Norse toppr (top), the Scots tap (top), the North Frisian top, tap & tup (top), the Saterland Frisian Top (top), the West Frisian top (top), the Dutch top (top, summit, peak), the Low German Topp (top), the German Zopf (braid, pigtail, plait, top), the Swedish topp (top, peak, summit, tip) and the Icelandic toppur (top).  Alternative forms are common; bubble-top in automotive & aeronautical engineering and bubble top in fashion.  Bubbletop is a noun and bubbletopped is an adjective; the noun plural is bubbletops.

Evolution of the Mustang's bubbletop: P-51C (top), P-51 III (centre) and P-51D (bottom).

“Bubbletop” began as World War II (1939-1945) era military slang for officially was described as the “bubble canopy”, the transparent structure sitting atop the cockpit of fighter aircraft, the advantages being (1) superior visibility (the purest interpretation of the design affording an unobstructed, 360° field-of-view, (2) improved aerodynamics, (3) easier cockpit ingress & egress (of some significance to pilots force to parachute and (4), weight reduction (in some cases).  Bubbletops had been seen on drawing boards in the early days of aviation and some were built during World War I (1914-1918) but it was the advent of Perspex and the development of industrial techniques suitable for the creation of large, variably-curved moldings which made mass-production practical.  The best known early implementations were those added to existing air-frames including the Supermarine Spitfire, Republic P-47 Thunderbolt and North American P-51 Mustang.  By 1943, the concept had become the default choice for fighter aircraft and the technology was applied also to similar apparatuses used elsewhere on the fuselage where they were styled usually as “blisters”.  In the post war years it extended to other types, most dramatically in the Bell 47 helicopter where the cabin was almost spherical, some 70% of the structure clear Perspex.

The enormous and rapid advances in wartime aeronautics profoundly influenced designers in many fields and nowhere was that more obvious than in the cars which began to appear in the US during the 1950s.  Elements drawn variously from aeronautics and ballistics did appear in the first generation of genuinely new post-war models (most of what was offered between 1945-1948 being barely revised versions of the 1942 lines) but it was in the next decade the designers were able to embrace the jet-age (a phrase which before it referred to the mass-market jet-airline travel made possible by the Boeing 707 (which entered commercial service in 1958) was an allusion to military aircraft, machines which during the Cold War were a frequent sight in popular culture).  On motif the designers couldn’t resist was the bubble canopy, something which never caught on in mass-production although Perspex roofed cars were briefly offered before word of their unsuitability for use in direct sunlight became legion.

GM Firebird XP-21 (Firebird I, 1953).

Not content with borrowing the odd element from aircraft, the General Motors (GM) team decided the best way to test which concepts were adaptable from sky to road was to “put wheels on a jet aircraft” and although they didn’t do that literally, by 1953 when Firebird XP-21 was first displayed, it certainly looked as though it was exactly that.  Its other novelty was it was powered by a gas turbine engine, the first time a major manufacturer in the US had built such a thing although a number of inventors had produced their own one-offs.  When the XP-21 (re-named Firebird I for the show circuit) made its debut, some in the press referred to it as a “prototype” but GM never envisaged it as the basis for a production car, being impractical for any purpose other than component-testing; it should thus be thought of as a “test-bed”.  The bubble canopy looked as if it could have come from a US Air Force (UFAF) fighter jet and would have contributed to the aerodynamically efficiency, the 370 hp (280 kW), fibreglass-bodied Firebird I said to be capable of achieving 200 mph (320 km/h) although it’s believed this number came from slide-rule calculations and was never tested.  Despite that, in its day the Firebird II made quite a splash and a depiction of it sits atop the trophy (named after the car’s designer, Harley Earl (1893–1969), the long time head of GM’s styling studio) presented each year to the winner of NASCAR’s (National Association for Stock Car Auto Racing) premiere event, the Daytona 500.

GM Firebird II (1956).

Compared with its predecessor, the Firebird II (1956), rendered this time in titanium was almost restrained, the Perspex canopy a multi-part structure over a passenger compartment designed to seat “a family of four”.  The family might have chosen to drive mostly in darkness because the heat build-up under the midday sun would have tested the “individually-controlled air conditioning”, a system upon which comfort depended because the Perspex sections were fixed; there were no opening “windows”.  Still, even if hot, the family would have got places fast because the same 200 mph capability was claimed.

GM Firebird III (1958).

The Firebird III was displayed at the 1958 Motorama and although GM never built any car quite like it, within a season, elements of it did begin to appear on regular production models in showrooms (notably the rear skegs which Cadillac used for a couple of years) and some of its features are today standard equipment in even quite modest vehicles.  The striking “double bubbletop” never made the assembly lines although some race cars have at least partially implemented the concept.  What proved more of a harbinger was the specification, the Firebird III fitted with anti-lock brakes, cruise control, air conditioning, an automated “accident avoidance system” and instead of a steering wheel, the driver controlled the thing with a joystick, installed in a centrally-mounted “Unicontrol & Instrument Panel”.  All these were analogue-era electro-mechanical devices too bulky, fragile or expensive for mass production, wider adoption in the decades to come made possible by integrated circuits (IC) and micro-processors.

1959 Cadillac Cyclone (XP-74).

Borrowing from the Firebird II, Cadillac also used a bubble top for the Cyclone (XP-74) concept car which in 1959 toured the show circuit.  Although it was powered by the corporation’s standard 390 cubic inch (6.5 litre) V8, there was some adventurous engineering including a rear-mounted automatic transaxle and independent rear suspension (using swing axles, something not as bad as it sounds given the grip of tyres at the time) but few dwelt long on such things, their attention grabbed by features such as the bubble top (this time silver coated for UV (ultra violet) protection) which opened automatically in conjunction with the electrically operated sliding doors.  The Perspex bubble canopies from fighter aircraft never caught on for road or race cars but so aerodynamically efficient was the shape it found several niches.

1953 Ferrari F166MM Spider by Vignale (left) and 1969 MGCGT (centre) and the MGC's replica hood in  fibreglass (right).

Bubbles often appeared atop the hood (bonnet) to provide clearance for components inconveniently tall (typically induction systems).  Most were centrally located (there was the occasional symmetrical pair) but the when BMH (British Motor Holdings, the old  BMC (British Motor Corporation) shoehorned their big, heavy straight-six into the MGB (1963-1980), it wouldn’t fit under the bonnet, the problem not the cylinder head but the tall radiator so the usual solution of a “bonnet bulge” was used.  However, for that to clear the forward carburetor, the bulge would have been absurdly high so a small bubble (usually, ones this size are referred to as "blisters") was added.  It probably annoyed some there wasn’t a matching (fake) one on the other side but it’s part of the MGC’s charm, a quality which for years most found elusive although it’s now more appreciated.  For MGC owners wish to shed some weight or for MGB owners who like the look, the “bonnet with bubble” is now available in fibreglass.

The winning Ford GT40 Mark IV (J-Car) with bubble to the right, Le Mans 1967 (left) and the after-market (for replicas) “Gurney Bubble” (right).

US racing driver Dan Gurney (1931–2018) stood 6' 4" (1.9 m) tall which could be accommodated in most sports cars and certainly on Formula One but when he came to drive the Ford GT40 Mark IV it was found he simply didn’t fit when wearing his crash helmet.  The original GT40 (1964) gained its name from the height being 40 inches (1016 mm) but Mark IV (the “J-Car”, 1966) was lower still at 39.4 inches (1,000 mm).  Gurney was the tallest ever to drive the GT40 and the solution sounds brutish but fix was effected elegantly, a “bubble added to the roof to clear the helmet.  Gurney and AJ Foyt (b 1935) drove the GT40 to victory in the 1967 Le Mans 24-hour endurance classic and the protrusion clearly didn’t compromise straight-line speed, the pair clocked at 213 mph (343 km’h), on the famous 3.6-mile Mulsanne Straight (which was a uninterrupted 3.6 miles (5.8 km) until the Fédération Internationale de l'Automobile (the FIA; the International Automobile Federation and world sport’s dopiest regulatory body) imposed two “chicanes”),  Known ever since as the “Gurney Bubble”, such is the appeal that they’re now available for any GT40 replica: Like the AC Shelby Cobra, the GT40 “reproduction” industry is active and there are many times more of these than there are survivors of 105 originals.

Ferrari 250 GT “Tour de France” LWB Berlinettas by Zagato: The “double bubble” roof (left), the Hofmeister kink (centre) and the famous “Z” kink, (right).

The Italian coachbuilding house Zagato was founded in 1919 by Ugo Zagato (1890-1968) and since the early post-war years, their designs have sometimes been polarizing (the phrase “acquired taste” sometimes seen), their angularity often contrasted with the lines of other, notably Pinninfarina and Bertone but unlike many which have over the years folded, Zagato remains active still.  One Zagato design never criticized was his run in 1956 of five Ferrari 250 GT “Tour de France” LWB Berlinettas, memorable also for introducing the signature “Zagato double-bubble roof.  The roof was practical in that it better accommodated taller occupants but it really was a visual trick and a variation on the trick Mercedes-Benz used on the “Pagoda” (W113; 230, 250 & 280 SL; 1963-1971) which they explained by saying “We didn’t lower the roof, we rained the windows”.  The other famous feature (which appeared on only one) was the fetching “Z” shape on the rear pillar, replacing the “Hofmeister kink” used on some others.

1962 Chevrolet Impala “bubble top” Sport Coupe (left), 1963 Ford Consul Capri (centre) and 1972 BMW 3.0CS (E9, right).

The 1959 Chevrolet quickly came to be nicknamed “bubble top” and the style spread, both within GM and beyond.  The “bubble top” reference was to the canopy on aircraft like the P-51D Mustang but was an allusion to the shape, not the materials used; on cars things were done in traditional glass and metal.  Across the Atlantic, Ford in the UK applied the idea to their Consul Capri (1961-1964), a two-door hardtop which the company wanted to be thought of as a “co-respondent's” car (ie the sort of rakish design which would appeal to the sort of chap who slept with other men’s wives, later to be named as “co-respondent” in divorce proceedings).  The Capri was a marketplace failure and the styling was at the time much criticized but it’s now valued as a period piece.  Chevrolet abandoned the look on the full-size cars after 1963 but it was revived for the second series Corvair (1965-1969).  A fine implementation was achieved in the roofline of the BMW E9 (1968-1975) which remains the company’s finest hour.

The bubble shirt and bubble tops.

The bubble skirt (worn by Lindsay Lohan (centre)) is one of those garments which seems never to quite die, although there are many who wish it would.  Once (or for an unfortunate generation, twice) every fashion cycle (typically 10-12 years), the industry does one of its "pushes" and bubble skirts show up in the high street, encouraged sometimes by the odd catwalk appearance; it will happen again.  While the dreaded bubble skirt is easily identifiable, the “bubble top” is less defined but there seem to be two variations: (1) a top with a “bubble skirt-like” appendage gathering unhappily just above the hips (left) and (2) a kind of “boob tube” which, instead of being tightly fitted is topped with an additional layer of material, loosely gathered.  The advantages of the latter (which may be thought of as a “boob bubble”) are it can (1) without any additional devices create the illusion of a fuller bust and (2) allow a strapless bra to be worn, something visually difficult with most boob tubes because the underwear’s outline is obvious under the tight material.

Radome

Radome (pronounced rey-dohm)

A dome-shaped device used as a protective housing for a radar antenna (although the word is loosely used and applied to structures of varied shapes in which radar equipment is installed).

1940–1945: A portmanteau word, a blend of ra(dar) + dome.  In electronics, radar is a device for determining the presence and location of an object by measuring the time for the echo of a radio wave to return from it and the direction from which it returns and in figurative use refers to a means or sense of awareness or perception.  Dating from 1940-1945, radar was originally the acronym RADAR which was creation of US scientific English: RA(dio)D(etecting)A(nd)R(anging).  In the way English does things, the acronym RADAR came to be used with such frequency that it became a legitimate common noun, the all lower-case “radar” now the default form.  Dating from 1505–1515, dome was from the Middle French domme & dome (a town-house; a dome, a cupola) (which persists in modern French as dôme), from the Provençal doma, from the Italian duomo (cathedral), from the Medieval Latin domus (ecclesiae; literally “house (of the church)”), a calque of the Ancient Greek οἶκος τῆς ἐκκλησίας (oîkos tês ekklēsías).  Radome is a noun & verb; the noun plural is radomes.

Radomes at the Pine Gap satellite surveillance base, some 11 miles (18 km) south-west of Alice Springs (population circa 34,000) in Australia's Northern Territory (left) and a random radome which was blown onto an Indianapolis street by a storm (right).

Officially, the operation in Alice Springs jointly is operated by the defence departments of the US and Australia and was once known as the Joint Defence Space Research Facility (JDSRF) but, presumably aware nobody was fooled, it was in 1988 renamed the Joint Defence Facility Pine Gap (JDFPG).  The Pine Gap facility is a restricted zone so it's not a tourist attraction which is unfortunate because it's hard to think of any other reason to visit Alice Springs.  FoxNews in June 2025 published pictures of the “random radome” which had “fallen from the sky” in Indianapolis, Indiana after a severe thunderstorm swept through the region, wind gusts as high as 65 mph (105 km/h, 56 knots) measured.  The spherical cap was reported as being the size of a “small shed” and it was “parked” neatly, the flat base next to the curb and in case any of the conspiracy theorists in the Fox New audience began to speculate about alien invasions or government plots, it was revealed the radome came from an installation at the nearby tech infrastructure company V2X.

Lindsay Lohan on the cover of Radar magazine, June-July 2007.  The last print-edition of Radar was in 2008; since 2009 it's existed in on-line editions.

Dating from the mid 1940s, the word radar began as the acronym RADAR, (RA(dio)D(etecting)A(nd)R(anging)), coined in the US and entering English as a word within years.  Specialized forms are created as needed (radar gun, radar zone, radar tower, radar trap etc); radar is a noun, verb & adjective; the noun plural is radars.  In English, whether a string of letters is an acronym, abbreviation, initialism or word is determined both by form and organic process and the strings can emerge in more than one category.  Although it wouldn’t for a few years be known as radar, the system first became well known (within a small community on both sides of the English Channel) in 1940 because the string of radar installations along the English coast played such a significant role in the Royal Air Force’s (RAF) defense during the Battle of Britain, the crucial air-war fought that summer.  What the radar did was to provide sufficient notice of an attack to enable RAF Fighter Command to react to threats in the right place at the right time (altitude was always a problem to assess) by “scrambling” squadrons of aircraft on stand-by rather than having to maintain constant patrols in the sky, something which rapidly would have diminished resources.

Radomes don’t actually fulfil any electronic function as such.  They are weatherproof structures which are purely protective (and on ships where space is at a premium they also protect personnel from the moving machinery) and are thus constructed from materials transparent to radio waves.  The original radomes were recognizably domish but they quickly came to be built in whatever shape was most suitable to their location and application: pure spheres, planars and geodesic spheres are common.  When used on aircraft, the structures need to be sufficiently aerodynamic not to compromise performance, thus the early use of nose-cones as radomes and on larger airframes, dish-like devices have been fashioned.

North American Sabre:  F-86A (left) and F-86D with black radome (right).

Introduced in 1947, the North American F-86 Sabre was the US Air Force’s (USAF) first swept-wing fighter and the last trans-sonic platform used as a front-line interceptor.  Although as early as 1950 elements within the USAF were concerned it would soon be obsolete, it proved a solid, versatile platform and close to 10,000 were produced, equipping not only US & NATO forces but also those of a remarkable number of nations, some remaining in front-line service until the 1990s.  In 1952, the F-86D was introduced which historians of military aviation regard as the definitive version.  As well as the large number of improvements typical of the era, an AN/APG-36 all-weather radar system was enclosed in a radome which resembled an enlarged version of the central bosses previously often used on propellers.

What lies beneath a radome: Heinkel He 219 Uhu with radar antennae array.

The size of the F-86D’s radome is indicative also that the now familiar tendency for electronic components to become smaller is nothing new.  Only a half decade before the F86-D first flew, Germany’s Heinkel He 219 Uhu had entered combat as a night-fighter, its most distinctive feature the array of radar antennae protruding from the nose.  The arrangement was highly effective but, needing to be as large as they were, a radome would have been impossible.  The He 219 was one of the outstanding airframes World War II (1939-1945) and of its type, at least the equal of anything produced by the Allies but it was the victim of the internal politics which bedevilled industrial and military developments in the Third Reich (1933-1945), something which wasn’t fully understood until some years after the end of hostilities.  Remarkably, although its dynamic qualities should have made volume production compelling, fewer than 300 were ever built, mainly because Adolf Hitler (1889-1945; Führer (leader) and German head of government 1933-1945 & head of state 1934-1945): (1) was less inclined to allocate priorities to defensive equipment (attack always his preferred strategy) and (2) the debacle of the Heinkel He 177 Gref heavy bomber (which he described as “the worst junk ever manufactured) had made him distrustful of whatever the company did.

Peak dagmar: 1955 Cadillac Series 62 Coupe de Ville.

As early as 1941, the US car industry had with enthusiasm taken to adorning the front of their vehicles with decorative conical devices they intended to summon in the minds of buyers the imagery of speeding artillery shells, then something often seen in popular publications.  However, in the 1950s, the hardware of the jet-age became the motif of choice but the protuberances remained, some lasting even into the next decade.  They came to be known as “dagmars” because of the vague anatomical similarity to one of the early stars of television but the original inspiration really had been military field ordnance.  Cadillac actually abandoned the use of dagmars in their 1959 models (a rare example of restraint that year and not extended to the rest of the design) but concurrent with that, they also toured the show circuit with the Cadillac Cyclone (XP-74) concept car.

1959 Cadillac Cyclone (XP-74) concept car.

Although it was powered by the corporation’s standard 390 cubic inch (6.5 litre) V8, there was some adventurous engineering including a rear-mounted automatic transaxle and independent rear suspension (using swing axles, something not as bad as it sounds given the grip of the cross-ply tyres of the era) but few dwelt long on such things, their attention grabbed by features such as the bubbletop canopy (silver coated for UV protection) which opened automatically in conjunction with the electrically operated sliding doors.  The decorative rear skegs (borrowed from nautical use where there were functional) had been see on earlier show cars (notably the 1959 "twin bubbletop" Firebird III) and they appeared on the 1961-1962 Cadillacs in two versions: skeg short & skeg-long.

1958 Edsel Citation Convertible (left) and 1964 GM-X Stiletto, a General Motors (GM) "dream car" built for the 1964 New York World's Fair.

Most innovative however was a feature which wouldn’t reach volume production until well into the twenty-first century: Borrowing from the North American F86-D Sabre, two radomes were fitted at the front, housing antennae for a radar-operated collision avoidance system (ROCAS) which fed to the driver information on object which lay in the vehicle’s path including distance and the length it would take to brake, audible signals and a warning lights part of the package.  Unfortunately, as was often the case with the concept cars, the crash avoidance system didn't function, essentially because the electronics required for it to be useful would not for decades become available.  As the dagmars had, the Cyclone’s twin radomes attracted the inevitable comparisons but given the sensor and antennae technology of the time, two were apparently demanded although, had Cadillac more slavishly followed the F-86D and installed a single central unit, the response might have been even more ribald, the frontal styling of the doomed Edsel then still being derisively compared to female genitalia; cartoonists would have had fun with a Cyclone so equipped seducing an Edsel.  In 1964, there's never been anything to suggest GM's designers were thinking of the anatomical possibilities offered by an Edsel meeting a Stiletto.

Skeg

Skeg (pronounced skeg)

(1) In shipbuilding, a fin-like projection sometimes supporting a rudder and protecting the propeller(s) at its lower end, located abaft a sternpost or rudderpost.

(2) In the design of smaller boats, an extension of the keel, designed to improve steering.

(3) In the slang of naval architects (in certain contexts), a stump or branch (the after-part of a ship's keel).

(4) In the slang of the GM (General Motors) stylists, a “lower fin”, matching the, seen in embryonic form on the 1959 Pontiac and used on certain 1961 Oldsmobiles and the 1961-1962 Cadillacs.

(5) The fin which acts as a stabilizer on a surfboard.  To suffer some injury after being hit by one of these fins is to be “skegged”.

(6) In Australian slang, a surfer; a person who leads the lifestyle of a surfer (used also derisively in the form “fake skeg” of those who adopt the style an appearance without actually surfing.

(7) A type of wild plum (obsolete).

(8) A kind of oat (obsolete).

(9) In Northern English dialectal use, a look or glance.

(10) In some cultures, a slang term applied to youth suggesting slovenliness, a predilection to petty crime and other anti-social behavior; also used widely in Scottish slang for a surprising variety of purposes including legs, trousers, dirt, scotch eggs, sex and women of loose virtue.

1590–1600: From a dialectal term for a stump, branch, or wooden peg, from the Dutch scheg (cutwater), of Scandinavian origin and related to the Swedish skog and the Old Norse & Icelandic skegg (projection on the stern of a boat).  In some Nordic languages, skegg means “beard” and was from the Old Norse skegg, from the Proto-Germanic skaggiją, from the primitive Indo-European skek, kek-, skeg & keg- (to jump, skip, move, hurry).  In English slang, skeggy is (1) the coastal Lincolnshire town of Skegness or (2) an inhabitant of Skegness.  The name of the Skegness is though a construct of the Old Norse skegg (beard) + -nes (headland) and was thought a reference to the geography, the original settlement situated farther east at the mouth of The Wash (thus jutting out like a beard from a face).  A link with the Faroese skegg (to jump, skip, move, hurry (and source of the given name "Skeggi")) is thought unlikely.  Skeg is a noun and skegged is an adjective; the noun plural is skegs.

A gang of four Sceggs, Sydney, Australia.

The skegs of nautical architecture should not be confused with the homophone Sceggs, the acronym for students of S.C.E.G.G.S. (Sydney Church of England Girls Grammar School), seen also in the adjectival forms sceggesque & sceggish (one whose style suggests something similar to the stereotypical student of the school); Those adjectives exist because Scegg is also "a look" and there are students from schools other than S.C.E.G.G.S so described, often in the form "she's such a scegg".  

Lindsay Lohan in wet suit, with surfboard, Malibu, 2011.  The stabilizing skeg is the black protrusion at the back of the board.

On nautical vessels, skegs where they exist fulfil a significant function but they are not an essential part of hull design.  A skeg is an external structural feature, a vertical tapering projection permanently fixed at the aft, usually close to the centre-line.  Most are located in front of the rudder and structurally can often be considered a sternward extension of the keel (the internal, longitudinal members which lend much strength of the hull).  Although in military vessels there are additional functions, the most significant contribution of a skeg is in hydrodynamics, a skeg designed to influence the flow patterns and thus affecting the dynamics of both the rudder (which is usually in line with the skeg) and propeller(s).  The design is thus a finely tuned equation because while a skeg inherently induces drag, the way it alters the flow pattern can reduces the drag and resistance suffered by the rudder and propeller(s), essentially by transforming the turbulent characteristics of the flow to laminar at the stern.  Historically, skegs were a vital component in maintaining a course and that’s still an important consideration in smaller vessels but in larger craft, improved rudder and advanced navigational as well as stabilization technologies like thrusters have meant skegs are no longer of the same significance in maintaining directionality.

An USN (US Navy) Iowa class battleship, showing the inner set of propeller shafts wholly enclosed in a pair of skegs.  On the big ships, the skegs were designed also to be load-bearing supports while in dry-dock.

In the modern age, skegs became an unusual feature on warships, a relative few so equipped and the designs varied, some with only par of their shafts inside skegs while others encased all.  Although the traditional design imperatives were shared with other ships, for navies, they offered the advantage of affording some degree of protection for rudders and propellers against torpedo attack.  Historically, another important attribute of skegs was what they added to a hull’s structural strength, making the (inherently weaker) stern resistant to outside forces and all the last of the US Navy’s dreadnoughts (Iowa, New Jersey, Missouri & Wisconsin, launched 1943-1944 and in commission variously until in 1992 the last was struck the Naval Vessel Register) featured skegs.  Their hulls narrowed towards the stern and to save weight lacked the sternpost plates the British, German and Japanese navies always fitted to their battleships; the skegs compensated for this, offering a hull with similar rigidity.

The US Navy’s South Dakota class battleships (South Dakota, Indiana, Massachusetts & Alabama, launched 1941-1942 and in commission 1942-1947) were fitted with an unusual set of skegs, the design dictated by the relatively short hull, the large outboard skegs helping to reduce the adverse effects of fluid dynamics induced by the stern's abrupt end.

However, advantages in engineering and metallurgy meant much of the functionality afforded by skegs came to be achieved in other ways so skegs became unfashionable in naval architecture.  The modeling and simulations made possible by supercomputers meant hull designs could be rendered which mastered the turbulence caused by fluid dynamics so rudders and propellers were less affected, making skegs in many cases a source of performance-sapping skin-friction drag with little compensating benefit.  Indeed, not only did this hamper performance, in some cases excessive vibration was caused, something which could only to a degree be ameliorated by changes to the propellers’ configurations.

Cadillac’s Skegs, 1961-1962

Cadillac Coupe DeVille: 1959 convertible (left) & 1960 hardtop (right).

The 1959 Cadillac’s tail-fins are the best remembered and most emblematic of the brief, extraordinary era during which the absurdly macropterous flourished.  They’re rightly known as “peak-fin” but it’s a myth they were the tallest because, measured from the ground, those on the 1961 Imperial are about a half-inch (12 mm) more vertiginous.  The attractions of the style however were fading and from 1960, GM began to tone things down, Chrysler following the lead (Ford and AMC (American Motors Corporation) never really got involved in the big fin business).  Another cultural phenomenon is that because of the large number of pink 1959 Cadillacs which now exist, many assume they were a common sight when new, the things perhaps made memorable by the sight of the one owned by the admirable Jayne Mansfield (1933–1967).  However, the factory never made a pink 1959 Cadillac and in the era, it was only in 1956 such a color was on the option list and Ms Mansfield had one of those while her 1959 convertible received a custom re-paint.

An inspiration, a step in the evolution and the result: A captured German V2 rocket (1945, left), a full-size clay mock up of a design proposal for the 1961 Cadillac (1958, centre) and 1961 Cadillac Coupe de Ville convertible (left).  The V2 is on display at the Australian War Museum, Canberra, Australia and the clay mock-up Cadillac was photographed at the General Motors Technical Center, Warren, Michigan.

For the 1961 range, Cadillac further pruned the fins but as compensation, the design staff added a "lower fin" and these, informally, they called “skegs”.  While in a sense just another of the era's many extravagances, the outgrowths could have been part of something even stranger because among the design proposals which emerged from the GMADS (GM Advanced Design Studios) was one which clearly was the ultimate expression of the motif of the 1950s which borrowed so much from the aerospace industry.  The proposed fins essentially were those of ballistic missiles which for decades were an evolution from the German Vergeltungswaffen zwei (V-2), developed first by the German military with the code name Aggregat 4 (A4).  Vergeltungswaffen is translated variously as "retaliatory weapons" or "reprisal weapons" but in English use is often written as “vengeance weapons”.  Aerodynamically, what was proposed by the ADS may have had something to commend it and certainly, such was the placement and size of the fins they'd have in some way interacted with the air-flow.  Whether the design was ever subjected to wind-tunnel testing (this was years before computers could emulate such research) isn't know but the look was sufficiently favored for an expensive, full-sized clay model to be rendered.  Ultimately the longer, though perhaps more restrained, skegs seen on the 1961 & 1962 cars were preferred.

1959 Buick Invicta Concept.

Detroit's stylists in the 1950s not only sketched a car with a big dorsal fin but authorization was granted to build one to test public reaction.  There was a precedent for the "third fin" because the Czech manufacturer Tatra had for years used them (out of necessity) and they'd provided essential stability for many LSR (land speed record) vehicles.  The Invicta concept didn't proceed to production.

Those who think Detroit's cars of the late 1950s & early 1960s were sometimes bizarre should look at the design proposals that were rejected.  Despite the clear exuberance in the the imagination, there's never been anything to suggest the stylists were stimulated by anything stronger than an after work martini.  Compared with some of the clay mock-ups, what emerged from the production lines hinted at rather than emulated missiles but should it be thought what was rendered in clay was wild, the archives of the GMTC (GM Technical Center) contain a wealth of sketches of truly bizarre design studies which didn't make the cut to reach the hands of the modelers.  Presumably, those sketches which survive are those the stylists thought deserved to be remembered and there must of been those which even the designer concluded needed to be shredded.  As the archives also demonstrate, those who criticize the fins and "bullet" taillights on the 1959 Cadillac have reasons to be grateful even stranger things were rejected.

Cadillac’s “skeg years”: 1961 (left) and 1962 (right).  There was a time when this sort of thing was just a fork of Detroit's design orthodoxy. "The past is a foreign country: they do things differently there."

It was an era of annual styling changes and switching the orientation of taillights from the horizontal to vertical was typical of what stylists each season did to “refresh” the line, a process which came to be known as “facelifting” (ie a figurative use from cosmetic plastic surgery: altering the appearance while retaining the underlying structure).  Although this basic body would have a four-year life (1961-1964), the abandonment of the skegs for its final two seasons was, by facelift standards, a quite major update, one prompted by a change at the top of GM’s design’s studios.  Also of note is the roofline on the 1961 Cadillac four-window Sedan DeVille ((Body Style 6239, top left) which used an implementation of GM’s so-called “flat-top”.

1959 Chevrolet Impala Sport Sedan (Flat Top).  This was the year of the "bat-wings" and "cats eyes" taillights.

Along with the contemporary “bubbletop”, in its pure form, GM’s flat-top lasted only two seasons (1959-1960) but the two are now Detroit’s most admired rooflines of the post-war years.  The “bubbletop” was a direct tribute to fighter aircraft but the flat-top (it was also dubbed “Flying Wing” but GM internally referred to the blade-like structure as the “cantilevered top configuration”) was mid-century modernism.  Available exclusively on the four-door hardtops, each GM division (Chevrolet, Buick, Oldsmobile, Pontiac & Cadillac) offered the dramatic look (production-line rationalization made economically viable by all five sharing a single, core structure) although there were several designations.

1959 Cadillac Four Window Sedan (upper) and 1959 Pontiac Vista (lower).

Up-market Buick (Four-Door Hardtop), and Cadillac (Four Window Sedan) weren’t very imaginative while Chevrolet and Oldsmobile choose Sport Sedan; only Pontiac showed much imagination in picking Vista, an allusion to the unusually good 360^o visibility the style afforded (although the curves in the glass did produce some distortions).  Shamelessly, even after ceasing to offer flat-tops, Pontiac continued to use the Vista name.  Cadillac’s final flat-top fling came in 1961 with a modified version using less rear overhang but the market impact was muted, the more conventional six-window four-door outselling it by more than five-to-one margin as preferences shifted towards for formal lines.  However, the look didn’t at once die because it lingered on the four-door Chevrolet Corvair until 1965 and between 1962–1978 the motif appeared on the Alfa Romeo Giulia.

Cadillac’s take on the “long & slightly less long” of it: 1961 Cadillac Six Window Sedan de Ville (Body Style 6329L, left) and 1961 Cadillac Town Sedan (Body Style 6399C, right).  In the brochures, the terms “Town Sedan” and “Short Deck” both were used.

One quirk of Cadillac’s brief embrace of the skeg was there were two iterations: skeg long and skeg short.  Whether in response to dealer feedback or in anticipation of some owners preferring their Cadillac in a more conveniently sized package, between 1961-1963 a “short-deck” option was made available on certain body styles.  Offered first on the six-window Sedan de Ville (as the “Town Sedan”), an encouraging 3,756 were built so the option was in 1962 offered on the four-window de Ville Sedan (Body Style 6398 and now called “Park Avenue”) but sales dropped to 2600.  The coming of the 1963 models marked the retirement of the short-lived skegs which thus ended their brief moment as something decorative although they continued the functional role in marine architecture.

1963 Cadillac Four-Window Sedan de Ville (Body Style 6239, left) and 1963 Cadillac Sedan de Ville Park Avenue (Body Style 6398, right).

Although smaller cars were selling well in other market sectors, among Cadillac buyers, the decline of interest in anything smaller was confirmed in 1963 when only 1575 of the Park Avenues were sold.  The 129.5 inch (3289 mm) wheelbase was common to the whole Sedan de Ville range but the “short deck” models were shorter by 7 inches (178 mm) for the first two seasons and an even more obvious 8 inches (203 mm) in 1963.  Space utilization was obviously a little better but the market had spoken; fewer than 8,000 of the short-deck models sold while the standard editions shipped in the tens of thousands, the flirtation with (slightly) more efficient packaging abandoned for 1964; in the course of the following decade, the Sedan de Ville would grow another seven inches (178 mm) and gain over 400 lb (181 kg).  It should be noted that by international standards, the truck capacity of even the abbreviated models was still quite generous, able effortlessly to accommodate two sets of golf clubs, something which later became something of a de-facto standard used in assessing the practicality of sports cars.  Jaguar used this feature as a selling point when the XK8 (1996-2006) was introduced because it wasn’t possible with all versions of the old E-Type (1961-1974).

1958 Cadillac Series 62 : Extended Length Sedan (Body Style 6239EDX, left) and the standard Sedan (Body Style 6239, right).

There was in the early 1960s much criticism that “full-size” US cars had become too big but the “short deck” venture was a departure for Cadillac which had for some years been making things bigger and in 1958 the company had even included the “Series 62 Extended Length Sedan”.  The Series 62 Sedan was already an impressive 216.8 inches (5.5 m) long but the Extended Length version measured an even more imposing 225.3 (5.7), the additional 8.5 inches (216 mm) all in the rear deck, creating a more capacious trunk (boot).  Whether buyers just liked the look or there really were a lot of them with much luggage, the elongated sedan sold well, some one in five of the sedans having the big trunk and there was of course a healthy industry in jokes about Mafia functionaries and other figures in organized crime grateful finally to have more space to transport the corpses.  Surprisingly perhaps, despite mafia hit men contributing to to sales numbers of 20,952 of the 103,455 (excluding Eldorados and “chassis only” sales) Series 62s produced in 1958 (some 20%), the Extended Length Sedan proved a single-season one-off.

For 1963, the short-deck models might have re-appeared for another dismal season but the skegs were abandoned, never to return.  The fins the design studio found harder to forsake, conscious perhaps it was on the 1948 Cadillac they’d first appeared.  Then, modestly sized, they’d been an allusion to the tail-planes used on the twin-boomed Lockheed P-38 Lightning (1939) but the fashion had passed and the fins had to go so, inch by inch, there was a retreat from the heights and exuberance of 1959 until in 1966 they were vestigial, a hint which for decades would be retained.

1961 Oldsmobile Super 88.  The rear skegs were thought necessary to offset the “pointed-look” of the fenders and the front ones (the closest equivalent in nautical use being hydrofoils) were there just so the front bumper matched the lines of the rear, emulating Pontiac’s approach in 1959.

Within GM, the skegs were not exclusive to Cadillac, appearing also on the 1961 full-sized Oldsmobile 88 & 98 although the motivation of the designers differed.  What Cadillac in 1961-1962 did was nothing more than a styling gimmick, concocted at a time when it was obvious the moment of the big fins was passing but the motif still exerted such a pull that they were re-interpreted on the path to extinction.  In the Oldsmobile design office, the skeg had a different purpose, the protrusions deemed necessary as a device to counterbalance the rearward point of the quarter panel that terminated in a “cigar-shape”.  Mercedes-Benz had used a (more conventional) variation of the idea of a “balancing appendage” when in 1957 the 300d (W189, 1957-1962) appeared with rear fenders enlarged and re-shaped to disguise the pre-war style of the coachwork used on the W186 (300, 300b & 300c; 1951-1957) which came to be referred to as the "Adenauer" because several were used as state cars by Konrad Adenauer (1876–1967; chancellor of the FRG (Bundesrepublik Deutschland (Federal Republic of Germany; the old West Germany, 1949-1990).

1969 Alfa Romeo Spider (Duetto).

Interesting, between 1966-1969, the Alfa Romeo Spider (Type 105/155 and known informally known as the Duetto) featured the memorable Osso di Seppia (round-tail, literally “cuttlefish”) coachwork which resembled what Oldsmobile did in 1961.  After 1970 and until the end of production in 1994, the Spider used variants of the Kamm tail which increased luggage capacity and presumably also conferred some aerodynamic advantage.  A professional designer could write a long, learned essay explaining why the later Kamm tail was a more accomplished achievement which avoided the Osso di Seppia's flaws but in the collector market it's the cigar-shaped original the purists covet.  Had the Italians added skegs as Oldsmobile did, they’d have had more about which to complain.

1959 Pontiac Bonneville Convertible.  In 1959 Pontiac’s big news was the “split grill” which would for decades be a brand signature and the five inch (125 mm) increase in the track, lending the division that year’s most memorable slogan: “Year of the Wide Track”.  Given all that, the modest skegs weren’t much noticed, especially because, at the rear, eyes were drawn to the pair of small blades adorning the upper surface.  The idea was first seen on the 1953 Chevrolet Corvette (where they’d appeared on the taillight nacelles (pods)) and although often referred to as “finettes”, in the documents of the GM Design Studio they were “taillight bezels” or “ornamental finlets”.

1959 Pontiacs: Bonneville (left) and Catalina (right).

The skegs were less noticeably skeggish than the later implementations by Oldsmobile and Cadillac because they were smaller and, at the rear, installed in the horizontal rather than the acute angle which made them so obvious on Cadillacs.  At the front, the angle was less than adopted by Oldsmobile.  Pontiac also used the “long rear deck” as a marker of a model’s place in the hierarchy, the Bonneville at 220.7 in (5,606 mm) in length being seven inches longer than the lower-priced Catalina at 213.7 in (5,428 mm).  While two inches (25 mm) of the difference was absorbed by the Bonneville’s longer wheelbase (124 in (3,150 mm) vs 122 inches (3,099 mm), the remaining bulk was found in eth rear deck.  However, unlike the Cadillacs, there were no “short & long skegs”, the bumpers of both Pontiacs being identical although there were other markers of “pricetaggery”, the Bonneville’s elliptical taillights noticeably elongated.

1955 Ford La Tosca.

A half-decade before Cadillac decided their customers needed skegs, Detroit had pondered the idea.  Shown in 1955, Ford’s La Tosca (named apparently after Giacomo Puccini’s (1858–1924) three act opera Tosca (1900) although the intended connection seems to have been a general sense of the “emotional and dramatic” rather than the fate of the doomed protagonist) was unusual in that it appeared not as a full-scale “concept car” but in the form of a ⅜ scale model, used to demonstrate the possibilities offered by a remote-controlled chassis, directed through the medium of radio waves.  To achieve this, rather than build custom components (as the Pentagon would have done), Ford’s engineers dipped into the corporate parts bin and wired together the regulator and relay from a power window apparatus, the electric motor used to lower a convertible’s soft-top, a power seat mechanism and a standard, 12 volt car battery.  The system worked flawlessly and, depending on the topography, La Tosca could remotely be controlled at distances greater than a mile (1.6 km).  According to Ford records, the project began simply as an “…internal exercise to show students in the Advanced Studio how hard it was, even for professional designers, to design a car” but so long did the model take to complete (the complex curves and canted structures challenging to render in what was then the still novel fibreglass) that “mission creep” intruded, thus the radio-controlled chassis.

1954 Lincoln Futura (1954) and Ford Mystere (1955).  In Detroit, these were at the time typical of what was authorized to be built as "concept cars", machines destined for the show circuit to gauge public reaction.  If they now seem rather wild, much of what never left the stylists' (they weren't yet "designers") sketch pads and drawing boards truly was bizarre.  

Stylistically, La Tosca was in the vein of the corporation’s other concept vehicles of the era such as the Lincoln Futura (1954) and Ford Mystere (1955), the trio reflecting the way the industry was applying motifs from missiles and jet-propelled aircraft such as Perspex bubble-tops, tubes, fins and exhaust nacelles.  Most of these proved to be brief, though memorable, fads of jet-age aesthetics although elements were easily recognizable in the 1958 Lincoln and GM of course would later take up the skegs.  The remote-control concept was ahead of its time though it did find a niche in model cars and aircraft.  In the twenty-first century, new versions of the technology are now mainstream with cranes, trucks and trains routinely operated from sometimes thousands of miles away although usually on mine-sites and other remote locations (experiments with vehicles on public roads are being undertaken).  Despite these advances, the industry regards the technology as transitional and intends as soon as practicable to remove the human (and thus costly and unreliable) element completely, re-allocating control to an entirely autonomous AI (artificial intelligence) model which, without complaint or toilet breaks, can be worked 24/7/365.