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
360o 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.