Saab Ursaab
| Company type | Prototype automobile |
|---|---|
| Industry | Automotive |
| Predecessor | Saab 91 Safir (aircraft) |
| Founded | 1945 |
| Founder | Gunnar Ljungström, Sixten Sason (development team leaders) |
| Headquarters | Linköping , Sweden |
| Products | Prototype automobiles |
Ursaab (meaning Proto-Saab), also identified as 92001 and X9248, represents the inaugural prototype among four vehicles developed by Saab AB, which at that period was exclusively an aircraft manufacturer. This initiative eventually led to the launch of Saab's first production automobile, the Saab 92, in 1949. Currently, this prototype is exhibited at the Saab Car Museum located in Trollhättan. The term "Ursaab" translates to "original Saab".
The vehicle's development was undertaken by a team of sixteen individuals under the leadership of engineer Gunnar Ljungström and designer Sixten Sason.
Design
In 1945, Saab AB, primarily a warplane producer, initiated an automobile design project internally designated as X9248.[1][2] This endeavor was formally named Project 92, with "92" following the production sequence after the Saab 91, a single-engine training aircraft.[3] The goal was to create a vehicle competitive with compact German models such as the Opel Kadett, VW Beetle, DKW, and Adler. The intended price point for consumers was set at 3200 SEK. Bror Bjurströmer, then head of design, produced a scale model at 1:25 and established key design criteria including a 2.75 metres (108.3 in) wheelbase and an overall length of 4.5 metres (177.2 in); adoption of a monocoque chassis; reducing aerodynamic drag by half compared to contemporaries; limiting total weight to 800 kilograms; powering the car with a transversely mounted two-stroke engine; and utilizing front-wheel drive. The selection of rear-hinged doors was made by Gunnar Ljungström, who headed the development group, aiming to minimize door damage when exiting garages.Template:Fix/category[citation needed] Before finalizing the production model—the Saab 92 in 1949—four prototypes were constructed, numbered from 92001 to 92004.
Development
The project commenced in Linköping, executed by a sixteen-member team led by engineer Gunnar Ljungström alongside designer Sixten Sason.[4] Since the preceding Saab product code pertained to an aircraft—the Saab 91 Safir—the automobile project adopted the designation Saab 92. Typically managed by the testing workshop, development responsibilities shifted to the tool workshop due to prior commitments with the Saab 91 Safir and the Saab 90 Scandia aircraft.
The engineers tasked with building the prototype lacked prior automotive manufacturing experience; notably, only two out of sixteen held driving licenses. They required knowledge about car production but had to maintain confidentiality throughout. Limited visits were made to Nyköpings Automobilfabrik (later known as ANA), but since that company mainly mounted bodies onto imported ladder frame chassis, these excursions provided less insight than anticipated. Additionally, existing literature covered pre-war automotive manufacturing methods exclusively, compelling the team to acquire much practical knowledge independently. A nearby junkyard served as both a resource for parts and inspiration. Furthermore, they procured several vehicles—including a DKW, a Hanomag, an Opel Kadett, and a Volkswagen—for detailed examination.
Concerns about structural strength influenced various design choices. Accustomed to aircraft construction where all openings were reinforced with load-bearing hatches, the team recognized this approach was impractical for a car body. Consequently, they reinforced structural integrity by minimizing rear window size using a split-window configuration and eliminating a rear bootlid.
Given the requirement for an exceptionally low drag coefficient—0.3—which remains impressive even today, aerodynamic testing featured prominently during initial evaluations. The resulting body shape was innovative and designed with safety considerations to withstand impacts effectively. Front-wheel drive combined with generously sized wheel arches enhanced winter driving performance by allowing snow accumulation without impeding wheel movement.
Construction
In the spring of 1946, a life-sized mock-up was crafted from alder wood with the help of carpenters from Motala. The model was coated in black using shoe polish. Additional labor was sourced from Thorells Kylarfabrik in Linköping to fabricate the steel body. Forming the 1.2 mm thick steel panels by hand presented significant challenges. By mid-1946, the initial prototype body was completed, manually shaped over a wooden frame. This metal forming process took place in Saab's confidential workshop located 30 meters underground.
A disagreement arose regarding the paint color—the Managing Director preferred black, whereas the deputy favored blue. However, since black paint had already been procured, the decision was effectively settled. Due to limited capacity at Saab's own paint facility, the team reached out to Aktiebolaget Svenska Järnvägsverkstäderna (ASJ), a Swedish railroad workshop based in Arlöv. ASJ had extensive experience painting trains and buses. Initially hesitant because they believed the vehicle was a management car similar to a DeSoto and would require extensive time, ASJ agreed to assist once they realized it was a prototype for a new automobile.
The prototype utilized a borrowed 13 kW (18 hp) two-cylinder two-stroke engine mounted transversely at the front. The original engine and gearbox were sourced from a DKW model but were subsequently replaced by components engineered by Gunnar Ljungström. The prototype engine blocks were produced by Albinmotor, whose leader, Albin Larsson, initially hesitated due to the complexity of the cooling channels in the engine block. However, after driving the prototype, Larsson reconsidered his position.
The Ursaab covered over 530,000 kilometers (330,000 mi), typically driven discreetly on narrow, muddy forest paths during early mornings or late nights. Today, it is preserved at the Saab museum in Trollhättan, featuring a restored grille and headlights suitable for road use. The name "Ursaab" translates to "original Saab."
In 1947, Sixten Sason refined the Ursaab design, leading to the creation of another prototype: the 92002. The most notable change between the 92001 and 92002 models was the hood (bonnet). The original hood design and use of an Opel Kadett hood mechanism complicated engine removal since it required rotating the engine 90 degrees and extracting the drive assembly with gearbox first. Drawing inspiration from American vehicles with stepped front ends, the redesigned hood offered easier access to the engine compartment. Following four additional prototypes, the design was finalized for production as the Saab 92. The Ursaab was unveiled to journalists on June 10, 1947, at Saab AB's headquarters.
References
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- Bibliography
- The SAAB Way, authored by Gunnar A. Sjögren
- Some Personal Memories from the Production of the First Car, by Sigvard Lenngren in Bakrutan 4-2006
- A Cat Among Hermelins or How the Foundation Was Laid for SAAB's Automobile Production at the Aircraft Factory, by Hans Osquar Gustavsson and Sigvard Lenngren in Bakrutan 4-2006