Posts Tagged ‘Mercedes Benz W125’

image

 

 

Interesting drawing of one of the dominant Mercedes W125 during the 1937 Monaco Grand Prix held on 8 August…

Manfred von Brauchitsch won from Rudy Carraciola and Christian Kautz, Goffredo Zehender was fifth, the only interloper to the Mercedes party was Hans Stuck’  Auto Union Type C which was fourth.

von Brauchitsch #10 and Caracciola below in their epic race for the GP lead, these 560bhp 5.66 litre cars GRAND in every sense of the word…

image

(unattributed)

Click here for an article on the Mercedes W125…

https://primotipo.com/2015/08/11/mercedes-benz-w125-1937s-dominant-gp-car-and-rudy-uhlenhaut/

Credit…

Imagno, unattributed

image

(Fox Photos)

Dick Seaman and Herr Heck in their Mercedes’ at Crystal Palace in 1937…

This promotional shot dated 7 October preceded the ‘International Imperial Trophy’ race, ‘the first international road race organised in London’ on 9 October. The event was the decider of the 1937 ‘BRDC Gold Cup’ between B Bira and Ray Mays ERA’s.

The cars above are Seaman’s Mercedes W125 GP car and Heck’s 1903 Mercedes Tourer. Seaman, a works Mercedes driver was back in the UK having contested the 1937 Donington GP a week earlier. He retired from the Leicestershire event after a collision with Muller’s Auto Union having started on the outside of the front row, Bernd Rosemeyer’s Auto Union Type C won the thrilling race.

Seaman did not contest the International Imperial Trophy race but was scheduled to thrill the crowds with some demonstration laps in his Mercedes. The race was significant as the first ever live BBC TV outside broadcast of motor sport.

image

BBC man in evidence as one of the Maserati 4CM’s and an Austin passes. Interested to know both driver names and the name of this corner if any of you can help? (Imagno)

The entry included Britain’s best plus the Scuderia Ambrosiana, which fielded Maserati 4CMs for Count Piero Trossi, Count Johnny Lurani and a Maserati 6CM for Luigi Villoresi. Private Maseratis were driven by Robin Hanson and Peter Aitken (6CM’s) and Archie Hyde (8CM). They were challenged by the ERA’s of Ray Mays , Arthur Dobson, B Bira, Ian Connell, Peter Whitehead and Charlie Martin.

image

It looks a bit chilly! L>R: Trossi, Senor Rovere, Lurani and Villoresi with one of the Ambrosiana Maserati 4CM’s (David Savill)

During Thursday practice Mays blew his ERA’s 1100cc engine, becoming a non-starter and effectively giving the ‘Gold Star’ to Bira by 3 points.

Leiff Snellman reported the race in 8w.forix.com thus; ‘The race was run in two heats plus a final and raced as a handicap event with Hyde and his 3 litre Maserati starting from scratch, the 1.5 litre Maseratis and ERA’s having a 10 seconds advantage and the Austins, MGs and the MG-Riley having a 50 seconds advantage’.

‘Winner of the first 10 laps heat was Maclure (Riley) followed by Dobson (ERA), Lurani and Whitehead. Villoresi retired with an engine problem. Trossi (Maserati) won the second heat after a tough fight with Martin (ERA) and B Bira (ERA) who finished second and third with Goodacre (Austin) fourth’.

image

Top left; Seaman, Bira, Trossi. Top right Trossi Maserati 4CM (David Savill)

image

Unidentified gaggle of cars during the meeting (Central Press)

Between the races Seaman jumped into the ‘Benz W125 and carefully did several laps in 2 min 4s, about the same speed as the cars during the heats. Many of the spectators must have heard stories about the spectacular show by the German cars the week earlier and were as thrilled by the speed, wheel spin and noise from the ‘Silver Arrow’ as the Donington crowd had been.

image

Seaman practices his W125 at Crystal Palace prior to raceday, the slippery nature of the surface evident from the gloomy English day (Getty)

‘Twenty cars started in the 15 laps final to fight for the £150 first prize. The race became a great duel between ERA drivers Bira and Dobson who left the rest of the field behind. Bira won by half a car length while Dobson received the Jarvis Trophy for the fastest lap. Goodacre’s Austin finished third. The Scuderia Ambrosiana cars were unable to challenge for the lead with Trossi an early retirement and Villoresi and Lurani having problems to follow the ERA’s. Villoresi finally finished in fourth place’.

image

Bira the happy winner (Central Press)

The Mercedes W125 went on display at the Mercedes-Benz showrooms in Park Lane, as was Rosemeyer’s car at the Auto Union showrooms.

Credit…

Fox Photos, Imagno, David Savill, Central Press

Leif Snellman’s Crystal Palace article in 8w.forix.com

Tailpiece…

image

 

 

avus 2 cars

The 1937 Avus-Rennen is one of ‘those races meetings’ I suspect most of us would have rather liked to attend, these photos are of Hermann Lang’s Mercedes W25 during testing the week before on 22 May 1937…

His car is a 1936 speed record chassis rebuilt with a long wheelbase and the ‘standard’ 5.7 litre straight-8 fitted to the W125 GP cars that season.

The ‘final’ race of the meeting was the fastest race ever until the Monza 500 in 1958, Rosemeyer’s Auto Union fastest practice lap, 176.7mph and the fastest race lap, in two of the heats 171.74mph by Rosemeyer and Lang!

avus tower

Hermann Lang testing his Mercedes W25 modified 1936 speed record car the week before the 1937 race (ullstein bild)

The Germans didn’t race at Avus during 1936, they were rebuilding Berlins fastest circuit in the world into something even quicker with the addition of the ‘Nordschleife’ and massive ‘wall of death’ banking at 44 degrees. Avus was built in 1921 and used for racing until 1998 when it was absorbed fully into Germany’s road network as autobahn # 115.

avu banking

avu unload

avu crowd

Rosemeyer and friends AU Type C (Max Ehlert)

The 1937 race was a Formula Libre event which 300000-400000 spectators attended, what a spectacle it must have been. Such was the level of national prestige involved the German teams went all out to win building special cars and testing them in three sessions before the meeting itself.

avus au

Rosemeyer on the Avus banking, Auto Union Type C Streamliner, Hasse or von Delius in AU C Type then Seaman W125 (Ullstein Bild)

avu kids

avu audi unload

AU’s were all Type C V16’s, 2 streamliners (Rosemeyer and Fagioli) and 2 open wheelers (von Delius and Hasse)

avu alfa

Non German cars also rans! Scuderia Ferrari Alfa Tipo 12C-36 of Nuvolari, Brivio and Farina withdrawn before the race

Because of concerns about tyre life, such was the weight, speed of the cars and tyre technology of the day, the 30 May event was split into 2 heats of 7 laps and a final of 8 laps comprising the first 4 placegetters from each heat.

The heats were won by Rudy Caracciola and Manfred von Brauchitsch in ‘Benz W125 and W25K-DAB(5.6V12) respectively, the final by Hermann Lang’s Mercedes W25K-M125. All these cars were ‘Stromlinien’ (Streamliners), single-seaters with all-enveloping bodywork.

avus race

Caracciola this side in Mercedes W125 and Rosemeyer Auto Union Type C (Ullstein Bild)

avu tree

avu audis

Rosemeyer #31 and von Delius AU Type C’s

Kolumbus.f1 has a well researched, detailed account of this meeting, click here to read it, just scroll down the page, there are a couple of other events before you get to Avus;

http://www.kolumbus.fi/leif.snellman/gp372.htm

During practice for the meeting Lang’s car, with wheel covers fitted was doing 390kmh when trapped air under the car ‘lifted the front wheels from the ground, luckily the driver kept calm and finally managed to bring the wheels back down’…the wheel covers were removed for the race!

avus wheel

Tyre technician checks out the Continental ‘slick’, big challenge keeping tyres up to these big, heavy, powerful cars. Lang’s car as per text (Ullstein Bild)

avu 32

von Delius 6 litre V16 being gently warmed up, what awesome cars

benz 37

Hermann Lang’s winning Benz W25K

Down the decades the role of ‘aerodynamic guinea pig’ has not always been conducive to drivers attainment of retirement age, Bernd Rosemeyer’s fatal Auto Union speed record attempt on 28 January 1938 an ‘in period’ case in point…

avus butt

Caracciola’s W125 Benz, Avus 1937 (Ullstein Bild)

Checkout this Avus ’37 Footage…

Etcetera…

avo cara

Caratch during testing, Northcurve Benz W125 (ullstein bild)

avu sign

Fagioli’s AU Streamliner Type C

avu butt

Love this shot for the contrast between Langs leading Streamliner W25 ahead o Dick Seaman’s openwheeler W125 ‘normal’ GP car

avu 1

Avus, Fagioli Auto Union during practice 27 May 1937 (Imagno)

avu 2

von Brauchisch’ big Benz 1936 W25 with 700bhp DAB V12 and Lang 1936 LWB speed record W25 5.7 litre Straight-8 ahead of one of von Delius or Hasse AU Type C open-wheeler 6 litre V16 (Heritage Images)

avu 3

Caratch and arch-rival Bernd, Avus ’37 (ullstein bild)

Credits…

All images not attributed by Ullstein Bild, Heinrich Hoffman, Imagno, Max Ehlert, Heritage Images, Kolumbus F1

Tailpiece: Stromlinien on display, place undisclosed 1937, am interested to know if any of you can pick the venue…

avus display

(Heinrich Hoffman)

 

 

image

(Sydney Morning Herald)

I wrote a long article about Peter Whitehead’s successful 1938 ‘Australian Tour’ which culminated in his ERA R10B, Bathurst, AGP win on 18 April, here he is enjoying a ‘cleanser’ at the races duration, click here to read it;

https://primotipo.com/2015/04/16/peter-whitehead-in-australia-era-r10b-1938/

This piece is a ‘photographic update’ of the earlier tome. It’s interesting the way photos sometimes ‘pop up’, in this case as a result of someone clearing out a house and finding a cache of photos of a man who was clearly a Whitehead fan ‘in period’.

Most of the shots were posted on an antiquarian website with a blog devoted to identifying unknown objects, via that medium they found the primotipo article above. Go figure the ways of this internet world! The photo’s existence 80 years later is indicative of just how much general press interest there was in Whitehead’s visit with the ‘fastest car to come to Australia’ at the time .

I received the assistance of a ‘panel of expert mates’ to ID the shots, many thanks to racers/fettlers/historians/enthusiasts John Medley, Patrick Ryan and Greg Smith for their ‘smarts’! Mind you there was not a unanimous view on all of the shots, opinions from others welcome.

ERA Australia Shots…

PW either during the 1938 AGP, Bathurst or at Rob Roy, Christmas Hills, Victoria. Whitehead ran with number 1 at both events, won both and set course records. Bathurst expert Medley says its Mount Panorama and Melburnian Rob Roy regular Pat Ryan’s vote is for the Clintons Road, Christmas Hills short ‘climb.

As you will see Whitehead is sans any form of head protection, not even the vestigial ‘cotton bonnet’ of the day; mad given Bathurst’s surface.

image

(Sydney Morning Herald)

The next 3 shots are of Whitehead going down the long Conrod Straight ahead of (ID Stephen Dalton) Barney Dentry’s #14 Riley. It would have been pretty wild, flat out in that ERA without helmet atop the gravel surface pinging past the gum-trees close by at around 150mph.

image

image

(Dave Sullivan Album)

image

Two shots ago but cropped closer to the cars; Whitehead and Dentry down Conrod (Dave Sullivan Album)

Refuelling R10B with fuel and topping up the radiator at Bathurst. Crew member Kenneth Maxwell at left.

image

(Sydney Morning Herald)

UK ERA R10B shots…

Start of the 1937 Donington GP, 2 October 1937 won by Bernd Rosemeyers #5 Auto Union Type C from the #3 von Brauchitsch and #1 Caracciola Mercedes W125’s

image

#2 Lang DNF gets the jump at the start in his W125 Benz from #4 MB Seaman DNF, #1 MB Caracciola #5 AU Rosemeyer and #3 von Brauchitsch MB on the outside. The next group comprises the 2 AU’s of Hasse 5th and Muller 4th. #8 are the Mays and #16 Whitehead ERA B Types both DNF (The Autocar)

The next photo is of Peter Whitehead leading Dick Seaman’s famous Delage at Donington during the Junior Car Club 200 Mile race and Andre Cup on 29 August, Seaman won the event in 15S8 Delage from the earl Howe and D Briault/Keith Evans ERA B Types.

The race was contested by a mix of 1500cc Voiturettes and Grand Prix cars; mainly Alfa Tipo B/Monza and Bugatti T51’s.

image

(The Autocar)

The Walker/Whitehead ERA leads the Seaman Delage at Donington in 1936, date unknown.

image

(The Autocar)

Hector Dobb’s Riley leads the Whitehead/Walker ERA R10B at Brooklands.

image

The Walker/Whitehead ERA ahead of a Bugatti, MG K3, MG NE at Brooklands

image

Credits…

Thanks again to John Medley, Patrick Ryan and Greg Smith for your period knowledge

Dave Dempsey and antiquers.com, Dave Warner Album on ‘The Nostalgia Form’ via Terry Walker

Tailpiece: ERA ‘Peter Partners’ Walker left, and Whitehead celebrating a race win, by Walker perhaps? at Donington in 1936…

image

(The Autocar)

 

 

w125

(Alan Fearnley)

Teammates Rudi Caracciola and Manfred von Brauchitsch #10 battle for the lead roaring by the ‘Hotel Beau Rivage’ in their Mercedes Benz W125…

This image is Alan Fearnley’s ‘Battle of Beau Rivage’ from his book ‘The Classic Car Paintings’ and ‘depicts a dramatic battle amidst the architectural wonderment of the principality pre-war’, von Brauchitsch won the race against team orders. Caratch won the European title in 1937, both he and Bernd Rosemeyer, Auto Union mounted, won 4 races apiece but Rudi had the larger points haul.

Manfred’s nickname was ‘The Unlucky Bird’, when he had this chance for a race victory he was not going to let it slip away. He said later in life that Alfred Neubauer, Mercedes famous team manager did not have much to do with him afterwards for the rest of his career. It was one of the few races Caracciola lost to another Mercedes that year.

The Mercedes W125 was Fearnley’s favourite machine ‘it seems to embody all the visual impact that a Grand Prix car should have’, his painting is a superb, dramatic work.

Check out my article on the Mercedes W125;

https://primotipo.com/2015/08/11/mercedes-benz-w125-1937s-dominant-gp-car-and-rudy-uhlenhaut/

Credit…

Alan Fearnley

 

monaco

Manfred von Brauchitsch,winner, Rudy Caracciola 2nd 1937 Monaco GP, held that year on 8 August. Loews Hairpin. These 2 were 2 laps in front of 3rd placed Christian Kautz in another Mercedes W125. (unattributed)

Mercedes Benz’ 1937 Grand Prix car was famously the most powerful racing car until the 7-8 litre Can Am aluminium Chev V8’s deployed in the early 1970’s finally exceeded its output of circa 645 bhp. It took the 1.5 litre turbo-cars of the late 1970’s for a Grand Prix car to best those numbers of 1937…

The 750 Kg formula of 1934 to 1937 created an ‘unlimited formula’ of the type only replicated by the Can Am Series of the mid-sixties to mid-seventies. The class was minimum weight based which meant the German teams of Auto Union and Mercedes Benz, bouyed by Government subsidies and rapidly advancing military technology were able to build very light and powerful cars…far more powerful than the regulators had imagined or intended!

rudy 1929

Mercedes GP contender in 1929, prior to the ‘serious program’ of the 1930’s. Rudy Caracciola wrestling the big SSK, sports car around Monaco to 3rd place. Race won by the ‘W Williams’ Bugatti T35B. Supercharged SOHC 6.8 litre straight 6, circa 250bhp. (unattributed)

fagioloi

In search of, and finding an apex! Luigi Fagioli in his Mercedes Benz W25 at the Coppa Acerbo, Pescara on 15 August 1934. Nuvolari and Brivio 2nd and 3rd in Maser 8CM and Bugatti T59 respectively. (unattributed)

The mid-engined, radical Auto Union ‘P wagen’ was launched in late 1933 to critical acclaim. Mercedes approach was more conventional, the W25 a front-engined car powered by a DOHC supercharged straight-eight which initially developed circa 315bhp @ 5800rpm. Suspension was all independent by wishbones and coil springs at the front and swing axles and reversed quarter elliptic springs at the rear. Hydraulic drum brakes were used. The cars won 4 Grands’ Prix and 2 Hillclimbs in 1934.

In 1935 the W25 was further developed, Rudy Caracciola won the reinstated European Championship. Tazio Nuvolari’s famous 1935 German GP win aboard his Alfa Romeo P3 the only non-German car to win a Championship GP from 1935 to 1939.

barcelona

Rudy Caracciola in his Mercedes W25B, Montjuic Park, Barcelona on 30 June 1935. Teammate Luigi Fagioli won the Penya Rhin Grand Prix with Rudi 2nd and Tazio Nuvolari 3rd in an Alfa P3. Carac won the European Drivers Title that year. (unattributed)

The capacity of the W25, initially 3.4 litres increased to over 4 litres developing over 400bhp. The M25 straight-8 became unreliable when enlarged to 4.7 litres and 490bhp. A 5.6 litre, 600bhp V12 was tested but the cars, the chassis shortened (becoming so small Caracciola couldn’t fit comfortably in it) and lightened became uncompetitive with reliability, engine and handling dramas, Auto Union winning many races.

german gp

Mercedes team at the foresters lodge ‘ Sankt Hubertus’ prior to the 1936 GP at the Nurburgring. Mercedes W25’s entered for Caracciola, von Brauchitsch,Lang, Fagioli and Louis Chiron. Best placed was the Fagioli/Caracciola car in 5th, Rosemeyer won in an Auto Union. (unattributed)

After the 1936 German Grand Prix, a catastrophic home race for the team, the best placed Mercedes-Benz in 5th position, it was clear that radical changes had to be made to the Mercedes sporting organization.

Management started by looking at the structure of their racing departments, the same issues of lack of nimbleness, communication and decisiveness which have dogged bigger companies such as Ferrari and Renault in recent decades are not new.

The organization used by Mercedes in 1936 had its roots before the First World War. After the death of Hans Nibel in 1934 the central design office was managed by ex-driver Max Sailer. Under him Albert Heess and Otto Schilling were engine design chiefs with Max Wagner the chassis supremo.

Construction, assembly and testing of the cars were handled by the experimental department led by Fritz Nallinger. Jacob Krauss managed chassis construction and Otto Weber engine assembly while George Scheerer, in charge of the dynamometer section, was responsible for engine testing.

Over the years communication between the experimental department and the sporting department led by Alfred Neubauer had begun to fail. ‘Too many cooks’ springs to mind…

bob

Bob Shepherd line drawing of the Mercedes Benz W125. (Australian Motor Sports)

A new technical department between the design office and the racing team was created in 1936. The Rennabteilung (racing department) took over the assembly and testing of the racing cars from the experimental department. In charge of the new department was gifted young engineer, Rudolf Uhlenhaut. He was born in London on 15 July 1906, (died 8 May 1989) his father German, his mother English. He joined Mercedes Benz in 1931 as a Munich University graduate, until 1936 Uhlenhaut had worked on passenger cars not on any of the racers.

uhlenhaut

Rudy Uhlenhaut testing a Mercedes W154 GP car at Monza in early 1938. Uhlenhaut was a race fast, analytical driver. He was entered as potential relief driver in the Le Mans campaign of 1955. W154 in early form, radiator treatment different on the cars as raced and obviously sans bonnet here. 1938 was a 3 litre supercharged/4.5 litre unsupercharged formula. Chassis essentially an SWB version of the W125 frame made possible by the use of the smaller/shorter 3 litre supercharged DOHC, 4 valve V12. Power 425-475bhp. Car dominant in 1938, Caracciola again European Champion. (Mercedes Benz)

On 12th of August 1936 the Rennabteilung tested one rebuilt 1935 car and two 1936 cars at the Nurburgring with Caracciola and Manfred von Brauchitsch the drivers. Tests included different tyres and shock absorbers. A 60kg lead weight was placed over the front suspension in an attempt to get more front grip. After two days the drivers decamped and Uhlenhaut drove the cars himself.

Rudy had never driven a racer before, even though he was used to testing road cars at high speed on the famous circuit. However, he soon settled in and proved to be an exceptionally gifted driver. Famously it has been rumoured that Uhlenhaut once went faster than Fangio at the ‘Ring during a test in the mid 50s. Whatever the case, Rudy was a talented tester and potentially a gifted racer had he the chance to strut his stuff, his wife and corporate commitments barriers to a racing career.

Uhlenhaut concluded as follows in relation to the W25’s he drove; toe-in changes caused by the old steering geometry were too big whilst suspension travel was too little making the springs bottom. The chassis was bending during braking. The experimental department had tried to solve the problems by using both hydraulic and friction dampers and harder and harder springs exacerbating the handling problems and violent kickback to the steering wheel. At the rear the attachment point for the De Dion axle could bend as much as 7-10cm during braking. Because the suspension was so stiff the wheels couldn’t follow the road. Again, famously, once during Uhlenhaut’s tests a wheel came off at high speed yet the car continued on three wheels as if nothing had happened.

After the 1936 Swiss GP ended in emphatic victory for Auto Union Uhlenhaut suggested further racing that year was pointless. So Mercedes retired from the season to focus their efforts on the 1937 car, the W125.

cutaway w125

Tubular frame of chrome molybdenum, double wishbone and coil spring suspension at the front, De-Dion tube and coil springs located by radius rods at the rear. Supercharged 5662cc 645bhp straight 8. 4 speed rear mounted’ box with ZF slippery diff. (Yoshihiro Inomoto)

Uhlenhaut’s assessment of the changes required resulted in a long wheelbase car with reduced polar moment of inertia. The chassis frame was much stiffer. The front suspension was new with greater travel and much softer springs. The car had hydraulic dampers only. The gearbox was changed to a constant mesh type improving reliabilty. During the season a new suction-type supercharger that proved superior to its precursor was also fitted.

The W125 was the first of the MB GP cars to have a tubular frame; of oval section nickel chrome-molybdenum steel of 1.5mm section. 5 cross tubes braced the frame.

The independent front suspension was again by way of unequal length wishbones, 8.45 inches and 10.59 inches in size upper and lower. Coil springs were used. Both hydraulic and friction shocks were used at the front, sometimes hydraulic shocks only.

Rear suspension was De Dion tube, the 2 end halves forged and machined from a single piece of nickel chrome-molybdenum steel. Two channel section radius rods provided fore and aft location with torsion bars, 33.2 inches long and 0.67 inch wide, providing the spring medium.

kautz

This shot of 3rd placed Christian Kautz shows the rear end treatment of the Mercedes W125, Monaco 1937. (unattributed)

Lockheed hydraulic brakes were used, they were of 2 leading shoe type, had Iurid linings with alloy shoes and drums, the latter had steel liners shrunk in.

It is perhaps indicative of preoccupations of the time with engines that about half the ‘Australian Motor Sports’ article which provided the basis of the cars technical specifications, is about the M125 straight-eight engine!

The engine, in typical MB practice was made up of 2 blocks of 4 cylinders, with a bore and stroke of 94x102mm, the engine undersquare, as was the practice of the time, giving a total capacity of 5662cc. The engine developed 645bhp at 5800rpm, the supercharger ran at twice engine speed and was pressurised at 12-14lb per inch.

photo (10)

Manfred Von Brauchitsch in his Mercedes W125 during the 1937 Coppa Acerbo, Pescara. He was 2nd, the race won by Bernd Rosemeyer’s Auto Union Type C. (unattributed)

In terms of the cars detailed engine design and construction;

The blocks comprised steel forged cylinders with water jackets and ports welded thereto in sheet steel. The cylinders were spigotted into the alloy, barrell shaped crankcase. The crank ran in 9 main bearings of split roller type made by SKF. Big ends were also of this type.

Pistons were provided by Mahle, conrods fully machined ‘H section’ made of nickel-chrome steel and had plain bronze bush gudgeon pins. Lubrication was by way of dry sump with a battery of gear type oil pumps and a front mounted oil radiator.

rudy 14

Lovely profile shot of Caracciola and the W125. Swiss GP, Bremgarten in August 1937. Rudy won the race from Herman Lang and Von Brauchitsch, also W125 mounted. (Mercedes Benz)

The cylinder head featured hemispherical combustion chambers with 2 inlet and 2 exhaust valves per cylinder at an included angle of 60 degrees. The exhaust valves were mercury filled for cooling. Two gear driven overhead camshafts were used, 1 plug per cylinder was fired by magneto. The heads were not detachable.

A Roots type supercharger originally blew air, in established Mercedes fashion into the carburettor but later in 1937, the blower was reconfigured to deliver the mixture in the more usual way. A twin-choke carb was used, the fuel mix a heady brew of 86% methyl alcohol, 4.4% nitro-benzol, 8.8% acetone and 0.8% sulphuric ether…who said fuel alchemy started in the 1980’s!?

A single plate dry clutch was mounted to the engine flywheel, the 4 speed gearbox, with ZF ‘slippery diff’ and final drive unit mounted to the rear crossmember.

The cars wheelbase was 9ft 2 ins and track 4ft 10ins, the W125 weighed 16.4 cwt.

benz

1937 Donington GP. Manfred von Brauchitsch from Rudy Caracciola, Mercedes W125. Rosemeyer won in his Auto Union from Manfred and Rudy. (unattributed)

The W125 proved a winner, Caracciola victorious at the German, Swiss, Italian and Hungarian Grands’ Prix giving him his second European Championship whilst Herman Lang won at Tripoli and von Brauchitsch at Monaco. The W125 was put to one side at the end of 1937, in an attempt to slow the cars down, there is nothing new in this!, the authorities mandated a 3 litre supercharged/4.5 litre unsupercharged formula for 1938/9. The chassis of the W125 evolved into that of the 1938 season W154, that car powered by a 3 litre supercharged V12 and similarly dominant.

A story for another time…

swiss

Start of the Swiss GP at Bremgarten in 1937. #14 and winner Caracciola W125 with #10 and #8 Hans Stuck and Bernd Rosemeyer both Auto Union Type C mounted. (unattributed)

Etcetera…

monaco

Mercedes team lineup of W125’s at Monaco 1937. #8 Caracciola 2nd, #10 Von Brauchitsch 1st, #12 Christian Kautz 3rd and #14 Goffredo Zehender 5th. Rosemeyer, the best placed Auto Union was 3 laps behind Von Brauchitsch! (unattributed)

avus

Streamliners at Avus in 1937. #35 Caracciola Benz W125 overtakes # 31 Rosemeyer Auto Union Type C in the Nordcurve. Rudy won the first race, Von Brauchitsch the second in another W125. (Mercedes Benz)

dick

Dick Seaman in his Mercedes W125 during the Masaryk Grand Prix, Brno September 1937. He was 4th. Caracciola won from Von Brauchitsch in another W125 and Herman Muller in a Auto Union Type C. (unattributed)

outline

Mercedes Benz W125 drawing. (unattributed)

rudy

Rudy Uhlenhaut in 1955 at a Hockenheim test session beside the ‘Blue Wonder’ Mercedes high speed transporter with a W154 GP car on ze back. (unattributed)

SLR

A truly wild road car for any era; Uhlenhaut and his road legal Mercedes 300SLR racer. (Mercedes Benz)

Bibliography and Credits…

‘Australian Motor Sports’ March 1952 article by Bob Shepherd

forix.com article on Rudy Uhlenhaut by Leif Snellman, Mercedes Benz

Finito…