Propeller

Propeller (pronounced pruh-pel-er)

(1) A person or thing that propels.

(2) A device with a hub to which are attached evenly spaced & shaped radiating blades, rotating on a shaft to pitch against air or water to propel an aircraft, ship etc.

(3) A wind-driven (usually three-bladed) device that provides mechanical energy, as for driving an electric alternator in wind plants (not a universal use).

(4) A steamboat thus propelled; a screw steamer (now rare).

(5) In fishing, a spinnerbait.

1780: The construct was propel + -er and the original sense was “one who or that which that propels”, an agent noun from the verb propel.  The verb propel was a mid-fifteenth century form from the Middle English propellen (to drive away, expel), from the Latin propellere (push forward, drive forward, drive forth; move, impel), the construct being pro- (the prefix here use in the sense of “forward direction, forward movement”) + pellere (to push, drive), from the primitive Indo-European root pel- (to thrust, strike, drive).  The meaning “to drive onward, cause to move forward” emerged in the 1650s.  The –er suffix was from the Middle English –er & -ere, from the Old English -ere, from the Proto-Germanic -ārijaz, thought most likely to have been borrowed from the Latin –ārius where, as a suffix, it was used to form adjectives from nouns or numerals.  In English, the –er suffix, when added to a verb, created an agent noun: the person or thing that doing the action indicated by the root verb.   The use in English was reinforced by the synonymous but unrelated Old French –or & -eor (the Anglo-Norman variant -our), from the Latin -ātor & -tor, from the primitive Indo-European -tōr.  When appended to a noun, it created the noun denoting an occupation or describing the person whose occupation is the noun.  The alternative spelling propellor dates from the early days of aviation in the first years of the twentieth century and is now extinct.  The standard abbreviation is “prop”, the use noted from military aviation since 1914.  Propeller is a noun; the noun plural is propellers.

Although the concept was used in antiquity and inventors and others (most famously Leonardo da Vinci (1452–1519))  had for centuries experimented, the use of the word in mechanical engineering dates from 1809 and was from nautical design describing the application of a “device for moving vessels on or under the water”.  In aircraft design the theory of the use of “propeller” appears in papers and drawings in the 1840s (in what were then described as “flying machines”) and models were built which demonstrated a “proof of concept” although it would be decades before lightweight engines of sufficient power existed to allow experiments in aerodynamics and construction to be powered.  The first known rendering of an aircraft propeller in a recognizably modern form dates from 1853.  The modern propeller uses two or (usually) more twisted, airfoil-shaped blades mounted around a shaft which are spun to provide propulsion of a vehicle through water or air, or to cause fluid flow, as in a pump.  The lift generated by the spinning blades provides the force that propels the vehicle or the fluid although this lift does not of necessity have to induce an actual upward force; its direction is simply parallel to the rotating shaft.

Lindsay Lohan getting off the propeller driven (technically a turbo-prop) NAPA Shuttle, The Parent Trap (1998).

The term “to disembark” was borrowed from nautical use and of late "to deplane" has entered English which seems unnecessary but the companion “to disemplane” seems more absurd still; real people continue to “get on” and “get off” aircraft.

The terms “impeller” & “propeller” both describe devices which use various implantations of the “rotating blade(s) design and are used in mechanical systems to take advantage of the properties of fluid dynamics to harness specific energy for some purpose.  A propeller is a type of rotating device with blades designed to propel or move a fluid (typically a gas or a liquid) by generating thrust; they are most associated with marine vessels, aircraft and some industrial applications.  In aircraft, propellers can be attached to wing-mounted engines or mounted just about anywhere on a fuselage although historically a location at the front has been most common.  In marine applications, propellers have on specialized vessels been located to the sides of the hull but they almost always emerge at or close to the stern.  An impeller is a rotating component with blades or vanes (almost always enclosed in a housing), typically used for fluid or air distribution, such as a pump or a compressor, the primary purpose being to increase flow or pressure.  The classic impellers those in centrifugal pumps where they spin, creating a flow of fluid (liquid or air) by imparting centrifugal force to the substance; in practice, impellers such accelerate liquids are more common.

So an impeller & propeller do much the same thing, using blades to propel some form of fluid.  The use of different terms is helpful because in practice they are very different devices and the distinction that one is external and the other located within a housing is handy and the origin of that seems to lie in the construct of impeller which came first, dating from circa 1680 (as an agent noun from the verb impel) in the sense of “someone or something which impels”.  What the design of an impeller does is use the energy from the rotation to increase the flow or pressure of the fluid and it that it’s the reverse of a turbine, the rotation of which extracts energy from, and reduces the pressure of the flow.  Engineers also have a number of highly technical rules about what is and is not defined as an impeller base on the whether the entry and exit of the fluids occur axially or radially but it seemed impossible to construct such definitions as absolutes so for most the simpler distinctions are more helpful.  In engineering, impellers have been recorded as a machine or component name since 1836.

News Corp website 22 January 2024.  To refer to a jet engine’s nacelle as a propeller could (almost) be defended on the basis it’s the jet engine which “propels” the aircraft but this is more likely an example of (1) the decline in the quality of journalists and (2) what happens when there are no sub-editors to correct the mistakes.  In time, artificial intelligence (AI) should improve things.    

The verb impel dates from the early fifteenth century and was from the Middle English impellen, from the Latin impellere (to push, strike against; set in motion, drive forward, urge on), the construct an assimilated form of in- (into, in, on, upon), from the primitive Indo-European root en- (in) + pellere (to push, drive), from the primitive Indo-European root pel- (to thrust, strike, drive).  The construct of the Latin impellō was in- +‎ pellō (push, drive), from the Proto-Italic pelnō or pelnaō, a nasal-infix present derived from the primitive Indo-European pelh- (to drive, strike, thrust).  The Latin prefix –in could be appended to create a negative (un-, non-, not etc) but here was used as an intensifier, another possible meaning (in, within, inside) coincidental to the mechanical devices being usually mounted within housings.

Propellers and impellers both use blades (although those of the latter are often in the form of a single piece wither cast, molded, or (occasionally) forged.  Turbines also use blade-like parts but these are called vanes and an industry which seems unable to decide on terminology is the burgeoning business of wind-power; the huge rotating assemblies on wind turbines are referred to variously as vanes, blades or rotors.  Rotor blades are familiar for the use in helicopters which is essentially an airframe where a large-scale propeller sits atop the structure, pointing upwards and rather than “propeller blades”, the accepted term is “rotor blades”, the design of which permits both lift and directional thrust although some exotic multi-engined machines have rotors in housings which, to maximize performance, can themselves be rotated to operate as conventional propellers.

Supermarine Seafang (1946) with contra-rotating propellers.  The Seafang (1946-1947) was powered by the 37-litre (2240 cubic inch) V12 Rolls-Royce Griffon (1941-1955) and was the final evolution of the Spitfire (1938-1948) derived Seafire (1943-1947) and Spiteful (1944), the trio all designed for use on Royal Navy aircraft carriers, the series enjoying success despite the basic design being hampered by the narrow undercarriage which made landings a challenge (something corrected on the Spiteful & Seafang).  Series production of the Seafang was contemplated but eventually only 18 were built because the jet-powered de Havilland Sea Vampire (1945-1950) proved capable of carrier operations, surprising some at the Admiralty who doubted the jets could operate from anywhere but land.

Contra-rotating propellers (known also as coaxial contra-rotating propellers) were implemented on some World War II (1939-1945) aircraft to address several aerodynamic and performance challenges associated with the fitting of piston engines developing power well in excess of anything the designers had envisaged.  The attraction were many and included reducing the “torque Reaction”, the phenomenon in which the torque generated by a spinning propeller cause an aircraft to yaw in the opposite direction of the propeller's rotation.  Pilots had long been trained to counteract this by use of the rudder (especially during take-off and low-speed-flight) but as engine power rose and propeller blades became bigger, heavier and more numerous, the effect greatly was exaggerated.  On two or four-engined machines, the obvious solution was to have the blades on each wing rotate in opposite directions but on the most powerful of the single-engined fighters, the two units were mounted one behind the other and this had the benefit also of allowing the rear propeller to recover energy from the swirling airflow (the slipstream) generated by the forward.  That allowed designers to harness the greater power without increasing the diameter of the propellers, avoiding issues with ground clearance and supersonic tip speeds (one of the reasons the Soviet Air Force’s swept-wing (unusually in a propeller aircraft) Tupolev Tu-95 (Bear) bomber (in service 1956-1993) was so loud was because the propeller tips exceeded the speed of sound).  Had jet technology not emerged when it did, the contra-rotating propellers would have become more common, wartime adoption was limited by the complexity in assembly and additional maintenance demands.

A flight of Republic P-47D Thunderbolts with under-wing drop-tanks.

The propeller also influenced other aspects of the aircraft.  When the prototype Republic P-47 Thunderbolt (1941-1945) first took to the air, it was the largest, heaviest single-seat piston-engined fighter ever produced (a distinction it still enjoys today).  Even the early versions used an engine rated at 2000 horsepower (later this would rise to 2800) and to harness this output demanded a large propeller.  The 12 foot (3.7 m) diameter of this four-bladed monster meant the landing-gear had to be extraordinarily long and the only way it could be accommodated was to have them retract inward, otherwise the heavy wing armament (8 x .50 inch (12.7 mm) M2 Browning machine guns (425 rounds per gun)) wouldn’t have fitted.

Chrysler XI-2220 V16.  The splined shaft is where the propeller attaches.

With things like the Thunderbolt, the Hawker Tempest and the later Supermarine Spitfires (and its derivatives), the piston-engined fighter achieved its final evolutionary form, the jet engine offering a path to performance unattainable while the physics of propellers imposed limits.  However, had the use of the A-Bombs not ended the war in 1945, development of the propeller aircraft would have continued because the early jets lacked thrust and reliability as well as suffering a rate of fuel consumption which rendered them unsuitable for long-distance operations.  With the war against Japan envisaged as lasting well into 1946, development of faster, more powerful piston engines continued although, given the parlous state of the Japanese military, it’s dubious at least there was much of a rationale for this but the military industrial complex is a creature of inertia and Chrysler’s research had perfected a new aero-engine for the Thunderbolt.  The XI-2220 was a 2,220 cubic inch (36.4 litre) V16 which was rated at a basic 2450 horsepower with some 4000 hp available when tuned for wartime use but with the end of the conflict, all such developments were cancelled and attention switched to the brave new world of jets and swept wings.  Thus ended the era of the big propeller-driven fighters, the V16 stillborn, as was the other extraordinary aero-engine on the drawing board: Britain's 32-cylinder Napier-Sabre H-32 which was a scaled-up version of their H24.

Contra

Contra (pronounced kon-tra)

(1) Against; contrary or opposed to; in opposition or contrast to; against, anti.

(2) An arrangement (usually between companies) whereby they exchange goods and/or services on a basis agreeable to both, often without any exchange of cash.

(3) In politics (sometimes used in a derogatory sense), a conservative; originally tied to Nicaraguan counter-revolutionaries.

(4) In accounting, as contra-entry or contra-account, an entry or account which cancels another entry or account.

(5) In music, an informal term for any of the musical instruments in the contrabass range (contrabassoon, contrabass clarinet or (especially) double bass).

(6) In dance, a type of country dance most identified with the New England region in the US (mostly obsolete).

1350–1400: From the Middle English contra (against, over against, opposite, on the opposite side; on the contrary, contrariwise) from the Latin contrā.  The Latin contrā (against) meant originally "in comparison with" and was the ablative singular feminine of com-teros, from the Old Latin com (with, together) + -tr, (zero-degree form of the comparative suffix -ter-).  As used as a noun in English, it meant "a thing which is against another" by 1778, an evolution of the earlier sense of "the contrary or opposite" from the 1640s.  English also picked up the practice from Late Latin in using contra as a prefix.  In French, it became contre- which passed into English as counter-, the Old English equivalent of which was wiðer (which survived in dialectical English as withers and in Scottish as widdershins), from wið (with, against).  There was also contraindicate (to indicate the contrary of (a course of treatment, etc)) from the 1660s, an evolution from the 1620s forms contraindicated & contraindication, contra-indicate the rare verb.  The use to describe the forces opposed to the Sandinista regime in Nicaragua since 1979 began in 1981, Contra a shortened form of the Spanish contrarrevolucionario (counter-revolutionary).  Contra is a noun, verb, adjective & adverb; the noun plural is contras.  

The Contras and the Sandinistas

Sandinista National Liberation Front (FSLN) Flag.

The contras were active from 1979 to the early 1990s in opposition to the left-wing government in Nicaragua (the Sandinista Junta of National Reconstruction).  The term was a short-form of la contrarrevolución (counter-revolution) although there were intellectuals in the movement who disliked the label because they thought it suggested something negative or reactionary.  They preferred comandos (commandos) though peasant sympathizers also called the rebels los primos (the cousins), reflecting in many ways the character of the early movement as one of civilian irregulars.  In the White House, contra wasn’t greatly favored either and by the mid-1980s, marketing types in the Reagan administration (1981-1989) introduced “democratic resistance” to press conferences though it never caught on outside 1600 Pennsylvania Avenue.  Undeterred, by the press’s scepticism towards newspeak, on the ground, the ever-optimistic CIA liaison operatives encouraged use of la resistencia.

National flag of Nicaragua.

Believing the domino theory applied as much to central America as once it had been applied in east Asia, almost from the beginning the contras received military and financial aid from the US.  Congress cut the appropriations but the White House continued support with funding provided through a variety of imaginative (and covert) money-making schemes and slush funds which culminated in the Iran-Contra affair (Iran-Contragate), the biggest scandal of the Reagan years.  The affair (noted if not openly discussed by the ayatollahs in the Persian ماجرای ایران-کنترا‎ and definitely not by the Contras in the Spanish Caso Irán–Contra) was a back channel CIA (the US Central Intelligence Agency) operation run out of the White House, secretly to sell weapons to the Islamic Republic of Iran, then subject to an arms embargo.

The cover story for the operation was the armament shipments were part of an intricate web of deals to free seven American hostages held in Lebanon by the Hezbollah, a paramilitary operation which started as modestly as many others but which would evolve into a something which simultaneously would effectively take over the Lebanese state while acting as the regional proxy of Tehran (or a sub-contractor to Iran’s Islamic Revolutionary Guard depending on the interpretation).  The story wasn’t entirely untruthful but the administration arranged the first sales prior to the hostages being seized.

Sandinista graffiti.

Ronald Reagan’s (1911–2004; US president 1981-1989) world view was never as simple as his detractors suggest but it was starker than most of the Washington establishment and he didn’t support the position, which had become predominate during the Cold War and certainly after the Vietnam war, that the geopolitical structure of the world should be thought of as stable and permanent.  That was the view of the power-realists like Henry Kissinger (b 1923; US national security advisor 1969-1973 & secretary of state 1973-1977), theorists who believed problems needed to be managed over decades whereas Reagan thought problems needed to be solved: the Soviet Union was a problem, Cuba was a problem and the Sandinistas were a problem.  The Congress however had prohibited the provision of aid to the Contras.

In the Spanish, contra was a direct inheritance from the Latin contrā and in the Old Spanish there was also cuentra as well, with a diphthongization of the stressed Latin /ŏ/. As the word was generally atonic, over time, the unstressed variant contra eventually prevailed.  The synonym is en oposición a.  Although in English “contra” is less frequently used as a “stand-alone” word as is the case in Spanish, it does appear, often as a kind of “verbal shorthand” where appears as a clipping of “contrary”.  That use may to some extent be class based because, pronounced correctly, the slipping doesn’t save a syllable, “contrary” said correctly as the “U” kon-tree rather than the “non-U” kuhn-trair-ee. 

In 1985, the administration began a diversion of the profits the Iran operation to the Contras although it’s still not certain the president authorized this, so many of the supporting documents having been destroyed, the lesson of Nixon’s tapes well-learned: If stuff gets burned it can’t become evidence.  Within a year the story broke and after many denials about many things, Reagan was forced to appear on nationally television, taking “full responsibility” for the affair, suggesting what began with good diplomatic intensions, ran astray in a classic case of mission creep.  A commission was appointed to investigate and concluded no evidence existed to prove the president either knew of or approved the detail of operations.  Although several dozen administration officials were indicted and some were convicted, many were overturned on appeal and while a couple served terms of probation, most of the rest were pardoned by President George HW Bush (1924–2018; George XLI, US President 1989-1993) even before coming to trial, some noting the evidence suggested George XLI had his own reasons for not wishing the some matters to be aired in court although whether that included the role the CIA allegedly played in the distribution of crack cocaine in US cities during the 1980s has never been clear.

Supermarine Seafang (1946) with contra-rotating propellers.  The Seafang (1946-1947) was powered by the 37-litre (2240 cubic inch) V12 Rolls-Royce Griffon (1941-1955) and was the final evolution of the Spitfire (1938-1948) derived Seafire (1943-1947) and Spiteful (1944), the trio all designed for use on Royal Navy aircraft carriers, the series enjoying success despite the basic design being hampered by the narrow undercarriage which made landings a challenge (something corrected on the Spiteful & Seafang).  Series production of the Seafang was contemplated but eventually only 18 were built because the jet-powered de Havilland Sea Vampire (1945-1950) proved capable of carrier operations, surprising some at the Admiralty who doubted the jets could operate from anywhere but land.

Contra-rotating propellers (known also as coaxial contra-rotating propellers) were implemented on some World War II (1939-1945) aircraft to address several aerodynamic and performance challenges associated with the fitting of piston engines developing power well in excess of anything the designers had envisaged.  The attraction were many and included reducing the “torque Reaction”, the phenomenon in which the torque generated by a spinning propeller cause an aircraft to yaw in the opposite direction of the propeller's rotation.  Pilots had long been trained to counteract this by use of the rudder (especially during take-off and low-speed-flight) but as engine power rose and propeller blades became bigger, heavier and more numerous, the effect greatly was exaggerated.  On two or four-engined machines, the obvious solution was to have the blades on each wing rotate in opposite directions but on the most powerful of the single-engined fighters, the two units were mounted one behind the other and this had the benefit also of allowing the rear propeller to recover energy from the swirling airflow (the slipstream) generated by the forward.  That allowed designers to harness the greater power without increasing the diameter of the propellers, avoiding issues with ground clearance and supersonic tip speeds (one of the reasons the Soviet Air Force’s swept-wing (unusually in a propeller aircraft) Tupolev Tu-95 (Bear) bomber (in service 1956-1993) was so loud was because the propeller tips exceeded the speed of sound).  Had jet technology not emerged when it did, the contra-rotating propellers would have become more common, wartime adoption was limited by the complexity in assembly and additional maintenance demands.

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 Sydney Church of England Girls Grammar School (S.C.E.G.G.S.), 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 part of commercial 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.