Mercedes 35 hp
1900: a fateful year for Daimler-Motoren-Gesellschaft (DMG)
DMG had expected a more positive course
of business at the start of the new century. Two black days in March
1900 changed the state of affairs. On March 6, Gottlieb Daimler,
inventor of the high-speed gas engine and co-founder of DMG, died aged
65. On the 30th of the same month, Wilhelm Bauer had a fatal accident in
the very first curve of the hillclimb race from Nice to La Turbie. This
marked the end of the Daimler "Phoenix" cars: afterwards, DMG adopted a
highly reserved attitude to motor sport.
Not so sportsman and salesman Emil Jellinek, however. As early as April
2, 1900, he demanded a more competitive car from DMG, with higher
performance but at the same time a lighter engine, a longer wheelbase
and also a lower center of gravity. Also, the engine to be newly
developed was to bear the name "Daimler-Mercedes". For the first time,
the name "Mercedes" appeared as a brand name and no longer merely as a
team or driver name.
In Jellinek's opinion, the only one capable of realizing his ideas was
Wilhelm Maybach, the ingenious technical brain of DMG. To give emphasis
to his detailed wishes, Jellinek also ordered 36 vehicles from DMG, with
a total worth of 550,000 Marks - in today's terms about DM 5.5 million:
a sensationally large order for DMG, and more were to follow later.
Pressure of time: the ingenious success of Wilhelm Maybach
As matters stood, only an extensively new design came into consideration for the car demanded by Jellinek. But how could this be done in the remaining, unusually short time before October 15, the desired delivery date?
Aluminum crankcase, two camshafts, controlled intake valves
First of all, Maybach developed the new
engine for the "Mercedes" car, the outline for which was already in his
mind. The horizontally divided crankcase was for the first time made
from aluminum. The cylinders, made in pairs from gray cast iron,
featured cylinder heads which formed part of the castings, unlike the
removable ones in the "Phoenix" car. With a bore/stroke ratio of 116 x
140 mm, the engine had a total displacement of 5918 cc, a good 400 cc
more than in the "Phoenix" car.
For the main bearings, Maybach used magnalium, an aluminum alloy
containing five percent magnesium. Like the exhaust valves, the intake
valves, which until then had been designed as 'snifting' valves - opened
by the vacuum pressure inside the engine - were now controlled by a
camshaft. The non-encapsulated camshafts to the left and right of the
crankcase were driven by an open toothed-gear power take-off on the
flywheel side.
Via a gear set arranged in its center, the exhaust camshaft drove the
low-voltage ignition magnets and a water pump for improved cooling
efficiency, while a further gear set at the front end drove a small fan
behind the radiator. Another new feature: each cylinder pair had its own
separate carburetor. In the range between 300 and 1000 revolutions,
engine speed was controlled via a lever on the steering wheel.
Smoother operation, less weight
All these improvements ultimately resulted in much smoother operation, more stable idling and good acceleration - a new quality in engine characteristics, which at that time was hardly believed possible. In addition to this the engine weight was reduced by 90 kg to around 230 kg.
Engine directly bolted to the chassis, pressed frame side members
Maybach no longer installed the engine into a chassis subframe, as was usually the case at that time. Instead, he narrowed the front frame section ahead of the pedal level, permitting the engine to be directly bolted to the side members. The latter were no longer laboriously beaded but for the first time made of pressed sheet steel by DMG. Both these measures not only reduced the weight but also provided for the lower center of gravity that Maybach was aiming at.
New coil spring clutch, single-lever gate shift, improved steering
Another completely new design was the
highly compact and automatically adjusting clutch, a coil spring made of
spring steel, which with the help of a small drum was attached to the
transmission shaft and fastened inside the flywheel. Further development
of the car at a later stage benefited from this design. A conical cam
regulated the spring tension during declutching.
The four forward gears and the reverse gear were engaged by means of a
single lever in a shift gate. This feature was as new as the improved,
light steering with its worm gear - a unit installed further to the rear
and at a relatively steep angle. The steering axles were moved further
toward the outside, closer to the wheel hubs, thereby significantly
reducing the impact of road shocks on the steering.
Longer wheelbase, wider track, more effective brakes
Compared to the "Phoenix" car, the
wheelbase was markedly longer (2245 millimeters) and the track wider
(1400 mm) - giving the new car significantly greater stability. Apart
from that, wheels of virtually the same size were now, at last, used on
the two axles, albeit in the traditional wooden twelve-spoke design.
The brakes were adapted to the higher engine output, thus the "Mercedes"
was fitted with 30 centimeter drum brakes on the rear wheels, operated
via a manual lever and a linkage, and with an additional foot-operated
brake.
Engine cooling: no longer a problem thanks to honeycomb radiator
One of the most sensational inventions on
this first "Mercedes" - and one that has essentially remained unchanged
to this day - was the honeycomb radiator.
Until then, coiled pipe radiators had customarily been used, their
efficiency leaving much to be desired. They had caused an enormous water
consumption or required very large and therefore heavy coolant circuits.
Maybach had taken a major step toward the solution of the cooling
problem as early as 1897 when he introduced a radiator consisting of a
large number of small tubes which were flushed by coolant and
additionally cooled by airflow. The latter permitted a marked reduction
in the required coolant reservoir which, however, was still a sizeable
18 liters.
Maybach achieved a major breakthrough with the honeycomb radiator first
incorporated in the "Mercedes". He had as many as 8,070 small square
tubes, each six by six millimeters in size, soldered together into a
completely novel, rectangular radiator. Cooling efficiency was
considerably increased and water consumption reduced by half to a mere
nine liters by the square tubes' larger passage cross-section and the
smaller gaps between the tubes. A small fan behind the radiator improved
cooling efficiency at slow speeds. The honeycomb radiator had been born
-the automotive cooling problem had become a thing of the past.
Sensational appearance of the 35 hp "Mercedes"
The new car was for the first time tested
on November 22, 1900, and the first "Mercedes" was delivered to Jellinek
on December 22. Before long, the styling design of the first "real" car
in history set the trend for the rest of the automotive industry,
causing a 'landslide' in design. The car's elongated silhouette, high
performance, honeycomb radiator, low-slung engine hood, long wheelbase,
shift gate, obliquely installed steering, equal-sized wheels on the two
axles and low weight were from then on regarded standard components of
the modern automobile.
The sensational successes in racing in 1901 of the Mercedes cars gave
credit to Maybach's new design. People also highly appreciated the fact
that the two-seater, once it was no longer used for racing, was easily
converted into an elegant four-seater by means of a rear bodywork
element that could be installed in just a few minutes - the ideal car
for cruising on fashionable avenues and promenades.
The successor: 40 hp Mercedes-Simplex
Naturally, Maybach and DMG were more than happy about the success of the 35 hp car and its lasting appreciation by buyers, automotive experts and the public at large. As early as March 1901, the product range was extended by the addition of the smaller 12/16 hp Mercedes and in August by a third model, the 8/11 hp Mercedes. Maybach began further developing the first Mercedes series in the fall of 1901 already. To start with, the 40 hp Mercedes-Simplex was designed as a new top model and direct successor to the 35 hp Mercedes. Its wheelbase was extended to 2450 millimeters, its operation made easier by the "automatic" declutching and deceleration of the drive shaft upon actuation of the shift lever. The improvement of operational comfort at this early stage is reflected by the model's epithet, "Simplex".
Better performance, flywheel fan, fourth brake, reduced weight