Press Release) The O 321 H was launched in 1954, the same
year that Germany’s national soccer team won the World Cup for the
first time. But few thought during production start-up that the new
Mercedes-Benz bus would also prove to be made of world champion
material. Taking into account chassis and production outside
Germany, the versatile bus enjoyed worldwide unit production figures
of nearly 30,000 over a long career spanning 16 years – more than
any bus before it.
Premiere in December 1954
On December 6, 1954, St.
Nicholas’ Day, the first O 321 H came off the production line in
Mannheim, the plant that not long before had been declared the
central bus plant of Daimler-Benz AG. The new bus followed a new
design principle. Its semi-integral design was a major departure
from the conventional chassis construction and, with the exception
of the major drive assemblies, removed all similarities in design
between buses and trucks once and for all. Just a few years earlier,
the Mercedes-Benz O 6600 H had heralded this development, with its
forward-control cab position and rear-mounted engine. Its body,
however, had been built on an entirely conventional ladder-type
with frame/floor assembly
The backbone of the O
321 H on the other hand was a frame/floor assembly designed to be
self-supporting. The body was then welded firmly to this
high-strength frame. Together these two components resulted in an
extremely rigid body shell, lending the overall design higher
stability, lower weight and – with the removal of the chassis side
members – a larger luggage compartment between the two axles. Coil
springs on the front axle instead of the leaf springs used hitherto
served to improve ride comfort. The O 321 H heralded a new era in
Mercedes-Benz bus design.
At the same time, the separate frame/floor assembly of the new bus
permitted the company to continue supplying conventional
bodybuilders with the chassis. And coachbuilders in Germany and
elsewhere gladly availed themselves of the opportunity to create
individual body designs for buses of every conceivable kind.
Pleasing to the eye
Nevertheless, as a
complete vehicle with three-pointed star, the original Mercedes-Benz
O 321 H was pleasing enough to the eye in its own right. The
curvaceous body created a thoroughly harmonious effect, the
distinctive oval radiator grille incorporating the large brand
symbol and circular headlamps. The same grille adorned the new
cab-over-engine trucks of the 1950s – a feature clearly reminiscent
of the legendary 300 SL – and forged an original brand bus face
which still endures 50 years after the premiere of the O 321 H in
the modern Mercedes-Benz Travego coach.
At the time of production start-up for the Mercedes-Benz O 321 H,
buses were far less specialized than they are today. A single model
series spanned the whole range from regular service bus to touring
coach. But the O 321 H was more than up to the task. On the one
hand, there was the regular service bus with wide, inward-folding
doors ahead of the rear axle, destination indicator box and a
soberly functional interior. And on the other, the vehicle came as a
comfortable and elegant coach with airy, glass-bordered roof, entry
behind the rear axle, hinged doors, luggage nets and finished in a
variety of creative, multi-colored liveries.
After two years, two different lengths
Despite the wide range
of equipment versions, the history of the O 321 H began with a
single model, 9.23 meters in length and with a wheelbase of 4.18
meters – what today would be a midi-bus. Two years after its
introduction, Daimler-Benz went a stage further with a longer
version of the bus, the O 321 HL. Both wheelbase and overall length
were extended by just under 1.5 meters. Until that point the coach
could seat a maximum of 37 passengers; now at 10.6 meters in length
and with two extra rows of seats the O 321 HL could accommodate up
to 45 passengers.
In both cases the power was provided by a pre-chamber diesel engine
mounted at the rear in the direction of travel. The six-cylinder
in-line unit from the OM 321 series had a 5.1-liter displacement and
delivered 110 hp. From 1962 the company responded to calls for
greater output by offering the larger OM 322 5.7-liter in-line
engine giving 126 hp. The power of both engines was transmitted by a
fully-synchronized five-speed gearbox.
Several visual enhancements
But it was not just
length and technology that saw change: over the years the look of
the Mercedes-Benz O 321 H was also revamped. While the early units
were plain and unsophisticated in appearance, in time particularly
the coaches went in for an ever-increasing abundance of chrome. This
included not only the frame for the radiator grille, but also a
broad molding below the front windshield, which continued along the
sides and clearly marked the vehicle’s waistline.
Thanks to a number of facelifts, the O 321 H also gained in stature
over the years. The original flat front windshield was enlarged and
extended further downwards from 1957 on. In 1961 it grew again in
size, this time upwards, providing passengers with a better view.
Then, in 1963, the O 321 H was given a new rear end with a large,
one-piece screen. Standing room also improved, thanks to a raised
roof in the mid-section. But by this time the bus was approaching
the end of an illustrious career in Europe. Already the first highly
specialized buses were beginning to take over from the O 321 H and
its regular service companion models, the O 317 and O 322.
Lengthy career in all corners of the globe
Throughout its long
history the O 321 H also enjoyed an international career. The bus
plant in Mannheim turned out more than 18,000 of these bestsellers,
roughly two thirds of which were complete buses, and one third
chassis to receive bodies. Many of these buses were destined for
export to other European countries, Africa and Asia. In 1965 the
plant also delivered 116 parts kits to Greece and four to Argentina.
Deliveries to Brazil were of a different order altogether, however:
from 1957 to 1970 over 11,000 parts kits were shipped across the
Atlantic. In total the then Daimler-Benz AG produced precisely
29,586 units of the Mercedes-Benz O 321 H / HL – a performance truly
befitting a world champion.