A handful of good prototype engineering images I located:
Citroen 7 CV
Image by pedrosimoes7
MotorClássico, Lisbon, Portugal
Traction Avant monocoque
Front torsion bar suspension
The Traction Avant, French for "front wheel drive", was made by André Lefèbvre and Flaminio Bertoni in late 1933 / early 1934. Although not the initial production front wheel drive car – Alvis constructed the 1928 FWD in the UK, Cord made the L29 from 1929 to 1932 in the United States and DKW the F1 in 1931 in Germany – it was the world’s initial front-wheel drive steel monocoque production vehicle. Along with DKW’s 1930s models, the Traction effectively pioneered front-wheel drive on the European mass automobile market place.
The Traction Avant’s structure was a welded monocoque (unitized physique). Most other vehicles of the era had been based on a separate frame (chassis) onto which the non-structural body ("coachwork") was built. Monocoque building (also called Unit Physique or "Unibody" in the US nowadays) benefits in a lighter car, and is now employed for virtually all vehicle building, even though body-on-frame building remains appropriate for bigger autos such as trucks.
This method of construction was viewed with wonderful suspicion in many quarters, with doubts about its strength. A sort of crash test was conceived, taking the type of driving the auto off a cliff, to illustrate its wonderful inherent resilience.
The novel design and style created the car really low-slung relative to its contemporaries – the Traction Avant usually possessed a distinctive appear, which went from appearing rakish in 1934 to familiar and somewhat old fashioned by 1955.
The suspension was really sophisticated for the car’s era. The front wheels were independently sprung, using a torsion bar and wishbone suspension arrangement, where most contemporaries utilised live axle and cart-sort leaf spring styles. The rear suspension was a easy steel beam axle and a Panhard rod, trailing arms and torsion bars attached to a 3-inch (76 mm) steel tube, which in turn was bolted to the monocoque.
Because it was significantly lighter than traditional styles of the era, it was capable of one hundred km/h (62 mph), and consumed fuel only at the rate of ten litres per one hundred kilometres (28 mpg-imp 24 mpg-US).
Traction Avant rear
1937 7C Coupe Traction Avant
A French "familiale" 11 F 1954, six windows, 9 seats
Citroën 11 Commerciale five-door
Traction Avant rears. The boot was lengthened and its volume doubled in Autumn 1952.[four]
The original model, which was presented on 18 April 1934, was a tiny saloon with a 1,303 cc (79.five cu in) engine. This model was known as the 7A, which was succeeded in June 1934 by the 7B with a higher-power engine of 1,529 cc (93.3 cu in). The 7B in turn, was succeeded in October 1934 by the 7C with an even greater-output 1,628 cc (99.3 cu in) engine. Later models have been the 11 (launched in November 1934), which had a 1,911 cc (116.six cu in) four-cylinder engine, and the 15 (launched in 1938), with a two,867 cc (175. cu in) six. The numbers refer to the French fiscal horsepower rating, or CV. The 11 was an 11 CV, but curiously the 15 was truly 16 CV. The 11 was constructed in two versions, the 11L ("légère", or "light"), which was the identical size as the 7 CV, and the normal model 11, which had a longer wheelbase and wider track.
Citroën planned two variants that by no means entered production, given that there was not enough funding available to develop them, except as running prototype automobiles. 1 was an automatic transmission-equipped model, based on the Sensaud de Lavaud automatic transmission, the other a 22 CV model with a three.8 liter V8. The transmission (which was really initially created for the Citroen) was a "gearless" automatic, employing the torque-converter alone to match engine revolutions to the drivetrain revolutions, significantly like the Dynaflow Transmission introduced later in the USA. The vehicle was supposed to have a much less spartan interior than the other Traction Avants and it was to function Citroën’s own new V8 engine. About twenty prototypes have been produced, but when the project was canceled in 1935 due to Michelin’s takeover they were most likely all destroyed.[citation required]
In addition to the 4-door physique, the auto was also produced as a two-door coupé with a rumble seat, as a convertible and as an extended length Familial model with 3 rows of seats. There was even a hatchback-kind Commerciale variant, in 1939, well ahead of its time, in which the tailgate was in two halves, the reduced of which carried the spare wheel with the upper opening up to roof level. A one-piece leading-hinged tailgate was introduced when the Commerciale resumed production in 1954 soon after being suspended during World War II.
In September 1939 France declared war on Germany and in June 1940 the German army quickly invaded and occupied Northern France. The war years were characterised by a desperate shortage of raw components for civilian market and of petrol, but these variables have been not apparent quickly. The Paris Motor Show scheduled for October 1939 was cancelled at quick notice, but Citroën’s personal planned announcements had involved the forthcoming 2CV model rather than any significant adjustments to the Traction. For the Traction, the final “normal” year in terms of production levels was 1939, and eight,120 of the 2910mm wheelbase 1628cc engined 7C models have been developed. This tumbled to 1,133 in 1940, which was the initial year when the plant suffered severe air-raid damage – on this occasion caused by a German attack – on three June 1940. Production of the vehicles was suspended in June 1941, by when a further 154 had been produced in the six-month period just ended. The 7C would continue to seem in Citroën price-lists until March 1944, but production of this smaller engined “7CV” version of the Traction was not resumed soon after the war. For the a lot more powerful 1911cc engined 11 B-light models, the equivalent figures were 27,473 units created in 1939, 4,415 in 1940 and two,032 for 1941, even though for this model production in 1941 ended only in November 1941 so the figure for that year represents 11 months of production.
In 1945 production restarted only slowly: the 11 B-light reappeared really tiny changed from the 1941 automobiles except that headlight surrounds were now painted rather than finished in chrome. By the end of December 1945 the year’s production had reached 1,525. Currency depreciation is evident from the car’s listed cost which had been 26,800 francs in January 1940, and had risen to 110,670 francs in October 1945. In 1945 the auto was the only model accessible from Citroën, and as one more sign of the instances, customers not in a position to supply their own tires were charged an extra 9,455 francs for a set of five. In May possibly 1946, presumably reflecting an easing of the war-time tire shortage, the auto could at last be bought with tires at no added cost, but by now the all round price tag of an 11 B-light had risen to 121,180 francs.
The 11 B-normal model, differentiated from the 11 B-light by its 3090mm wheelbase, knowledgeable a comparable drop off in volumes between 1939 and 1941, with just 341 cars produced for the duration of the first seven months of 1941. Right after the war, a single 11 B-normal was developed in 1946, in time to be presented at the October 1946 Paris Motor Show: production constructed up throughout 1947, but for the duration of the car’s ten-year post-war period the shorter 11 B-light would, in France, continue to outsell the 11 B-normal.
Initially the French army lacked enthusiasm for the Citroën Traction, believing that it presented insufficient ground-clearance for their needs. Nonetheless, by September 1939 roughly 250 had found their way into military service. With losses of automobiles at the frontier mounting, Citroën supplied a further 570 to the army in between February and Could 1940, and subsequent deliveries almost certainly took location just before military defeat intervened. In the course of the war many of the automobiles were reregistered with "WH…" (Wehrmacht Heer/Army command) license plates, obtaining been requisitioned by the German Army. These gave reliable service each in France and further afield, notably in Libya and Stalingrad. Tractions have been also favoured by the Resistance, and as occupation gave way to Liberation they turned up all more than France with FFI inscribed proudly on their doors. Less gloriously, the automobiles were identified as favourites among gangsters such as the then infamous Pierrot le Fou, and his Traction gang.
UK built automobiles
Left-hand drive versions had been built in Paris, in Forest, Belgium, in Copenhagen, Denmark for the Scandinavian market place, and correct-hand drive cars in Slough, England. The Slough version of the 11L was named the Light Fifteen and the long wheelbase 11 was referred to as the Large Fifteen. This confusing terminology referred to the British fiscal tax rating of the time, which was greater than the French, so the 11CV engine was 15HP in England. The 15CV model was known as "Big Six" in reference to its six-cylinder engine. They have been equipped with the leather seats and wooden dashboards popular in the UK, had a 12-volt electrical method and had been distinguished by a diverse radiator grille and distinct bumpers. Some models also had a sliding sunroof.
A 1,911 cc (116.six cu in) Light Fifteen tested by the British magazine The Motor in 1951 had a leading speed of 72.6 mph (116.eight km/h) and could accelerate from 0–60 mph (97 km/h) in 29.7 seconds. A fuel consumption of 25.two miles per imperial gallon (11.2 L/one hundred km 21. mpg-US) was recorded. The test car cost GB£812 including taxes.[five]
A two,866 cc (174.9 cu in) six-cylinder model was tested by the very same magazine in 1954 and for this vehicle the best speed found was 81.1 mph (130.five km/h), acceleration from 0–60 mph (97 km/h) 21.2 seconds and fuel consumption 18.six miles per imperial gallon (15.two L/100 km 15.five mpg-US). The test vehicle expense GB£1,349 like taxes.[six]
Citroën 11 CV Légère
The Traction Avant used a longitudinal, front-wheel drive layout, with the engine set effectively within the wheelbase, resulting in a really favourable weight distribution, aiding the car’s sophisticated handling qualities. The gearbox was placed at the front of the automobile with the engine behind it and the differential among them, a layout shared with the later Renault four and 16 and initial generation Renault five but the opposite way round to numerous longitudinal front-wheel drive vehicles, such as the Saab 96 and Renault 12 and 18 and most Audi models. The gear alter was set in the dashboard, with the lever protruding through a vertical, H-shaped gate. Due to the fact this vertical orientation could have resulted in the auto dropping out of gear when the lever was in the upper positions (i.e., second or reverse gears), the gear shift mechanism was locked when the mechanical clutch was engaged and released when the clutch pedal was depressed. The outcome of this layout, along with pendant pedals, umbrella-sort handbrake handle and front bench seats, was a very spacious interior, with a flat and unobstructed floor. The low-slung arrangement also eliminated the want for running boards to step into or out of the car. These features created them ideal for use as limousines and taxi cabs, and they were quite well-known among drivers and passengers alike. Until 1953, black was the only color offered.
Effect on Motorsport
Another technical significance of Tranction Avant was the cast aluminium alloy transaxle, which was pioneered by Hans Ledwinka in the early 1930s for Tatra V570 utilised in front of the engine positioned in the rear, but was really radical at the time.
As well as being a considerable component of the weight savings, the manufacturing facility for this transaxle contributed to the under talked about financial crisis. But when John Cooper looked for a light transaxle case for Formula 1 rear engine revolution, Traction Avant unit was about the only candidate, as Volkswagen magnesium alloy transaxle was a lot smaller and lacking the space needed to property heftier gears needed for Formula 1. The Traction Avant transaxle was utilised on Cooper T43 which won a F1 championship race as the very first mid-mounted engine automobile to do so in 1958, and on its successors Cooper T45, T51 and T53. Cooper T51 won the GP World Championship in 1959.
Unlike the Volkswagen alloy case used by Hewland, the Traction Avant case could not be utilized up side down, as the input shaft height was much larger in relation to the output shaft axis so that the oil level needed to lubricate the gears would exceed the then-unreliable input shaft oil seal height if employed upside down. So the engine necessary to sit higher above the ground with the oil sump space beneath, which was not necessary by dry-sump racing engines. But the French transaxle was used by numerous racing automobile constructors in the late 1950s to 60’s with various levels of success.
In the case of Jack Brabham, who personally visited the ERSA foundry in Paris to discuss a possibility to strengthen the case ,[eight] the transaxle became known as "ERSA Knight" with an further spur-gear set mounted in the bellhousing spacer (engine to transaxle adapter) recommended by Ron Tauranac, named for Jack Knight who designed the modification and produced the straight-reduce gears. The height offset produced by the spur gear set enabled the engine to sit lower, and became the reason why Cooper T53 was known as the ‘Lowline’, which not only made Brabham the World Champion in 1960 but also became the precursor to the establishment of Brabham as a Formula A single constructor.
Effect on Citroën
1954 six-cylinder 15CV with hydropneumatic suspension fitted to the rear wheels – in ‘high’ position
Traction Avant as modern wedding car
The development charges of the Traction Avant, combined with the redevelopment of its factory, had been extremely high and Citroën declared bankruptcy in late 1934. The biggest creditor was Michelin, who then owned Citroën from 1934 till 1976. Beneath Michelin, Citroën was run as a study laboratory, a test bed for their radial tires and new automotive technologies.
In 1954 Citroën’s experiments with hydropneumatic technologies produced its first result, the "15H" – a variant of the 6-cylinder model 15 with a self-leveling, height-adjustable rear suspension, a field trial for the revolutionary DS released the following year.
Directly soon after the introduction of the Citroën ID, a simplified and much more competitively priced version of the nonetheless revolutionary DS, production of the Traction Avant ended in July 1957. Over 23 years, 759,111 had been built, such as 26,400 assembled in Slough in England, 31,750 assembled in Forest near Brussels and 1,823 assembled at Cologne in Germany. The total reflects the production stoppage for the duration of World War II.
The Traction Avant nowadays
Big Fifteen sedan
In 2006, the oldest surviving 7A has production quantity ("coque nr") AZ 00-18, and is displayed in partly dismantled shape (engine and front wheels detached) in the Citroën Museum in Paris. The oldest operating 7A is possibly number AZ-00-23, which was, till 1 September 2006, in possession of a Dutch owner and is now with a Slovenian owner.
Traction Avants are fairly robust autos even by contemporary requirements nevertheless, they are prone to leaking water inside the cabin and care requirements to be taken when acquiring one. Each few years, Traction Avant enthusiasts ship their autos to an exotic location for a rally. In 2002, for example, a group of more than 30 Traction Avants drove from Los Angeles to New York with no incident. 
G-92 “Krut” Jet Fighter
Image by Backward Matt
For also lengthy the engineers of the Kingdom’s navy laughed at the engineers of the air force, and for excellent purpose the Sky Ram produced by Meloa Industries was a disastrous tiny plane and paled in comparison to the Neustrasian’s Maelstrom supply.
But no more soon after the -ahem- "perfectly legal" "acquisition" of the subsequent generation jet engine prototype developed by the MURICANs, a secret project was contracted with Piccolo Aircraft. The majority of Meloa Industries personnel left to make naval versions of the Maelstrom for the major naval designers, but a handful of
crazy, stubborn determined people joined the struggling engineers of Neustrasia’s Mayenne and a Georgian firm, founding Piccolo Aircraft which worked beneath the radar (literally, in some situations) to create the Piccolo G-92 "Krut" to outdo all other jet fighters ever created up to that point. After 92 diverse design and style prototypes (most of them dying as wooden models in air tunnels) primarily based of the Manchot, Direwolf and possibly a handful of stolen Germanikan fighters, the design and style team went through forty six pounds of coffee beans, five of some of Neustrasia’s best pilots, a few water blessings to purge demon spirits, and a certain wealthy man’s life savings going to charity after losing a bet the fighter flies, and it flies nicely! So properly, in truth, that many of its elements are classified. :^)
Also, unknown to most of the globe, but very perplexing to the military leaders of Neustrasia, all their ideal pilots not already out for active duty were mysteriously re-assigned. This is why the ideal pilots of Terra get to fly the greatest fighter of Terra. 8^)
Note that all of that rambling is flavor text for the fictional universe of D&C IV, which is set in an alternate 1947.
IS-1 Sęp bis ‘SP-552’
Image by Hawkeye UK
On show suspended in the major show hangar at the Muzeum Lotnictwa Polskiego
The following information is taken from the museum internet site:-
"This is a single seater, all wooden, higher functionality glider of a higher wing cantilever configuration. The wings are equipped with divided flaperons, flaps, aerodynamic brakes and interceptors. In 1945, the group of gliding enthusiasts decided to re-activate the Silesian Glider Workshops, which had been established ahead of the Second World War. As a outcome of this initiative, the Gliding Institute was established in 1946. Its objective was to design and style new gliders, utilizing Polish encounter in this field.
The Sęp (vulture) was the very first after-war Polish building made at the Gliding Institute in Bielsko Biała. The initial style was carried our by engineers: Józef Niespał and Władysław Nowakowski. Despite hard occasions the prototype was flown on 2nd June 1947and currently in July of the very same year, the Sęp flown by Adam Ziętek represented Poland on the International Gliders Competitors in Samedan, Switzerland. It came eight. The Polish glider was the only new construction there. The other participants flew the pre-war or the captured German gliders To the subsequent examples a few minor adjustments (in the wings building and the cockpit equipment) have been introduced. The modified version bore the "Sęp bis" designation.
The total production quantity (collectively with prototypes) was six gliders, the last 1 was nonetheless flying at the starting of 1960’s Flying the Sęps, the Polish glider pilots set many domestic and planet records.
The IS-1 Sęp bis, displayed, bearing the SP-552 markings, was in service from 1948 till 1960, and took part in several different championships. In 1949, Irena Kempówna established two speed records. In 1964, the glider was handed over to the museum."