Manoeuvrability calls for an optimal track length to wheel
diameter ratio. In order to check on this aspect of the chariots a
comparison was made with the equivalent ratios of contemporary sulkies,
being these vehicles designed with the best technology actually available
for races on flat grounds.
The conclusion was drawn that more than
three thousand years ago some of the technical and scientific principles
used in machine mechanics today were employed with astounding
ancient vehicles, especially those dating before our age, have been lost
owing to their wooden structure. An exception are the chariots of the
Egyptian Pharaoh Tut Ankh Amun time, seven of which are located in Cairo
and one in Florence. The Authors have examined some aspects of the
construction of the chariots to show that in those times technical
capabilities were extremely developed. In fact, it was necessary to secure
the following characteristics: sturdy construction to reach a good speed
(around 40 Km/hour), manoeuvrability (especially quick turns), steadiness
(avoidance of toppling), durability and comfort. In the years that ancient
chariots were built the only material available was wood. Metals were
employed only in very limited amounts. It is interesting to note that the
choice of different kinds of wood was extremely sophisticated, in
particular those employed for the axle arms and naves where the need of
endurance is paramount.
Sulkies are built to achieve a net reduction in the horse's energetic
cost of locomotion, thereby enabling the horse to travel faster. Being
this the purpose, Egyptian chariots can be rated as inferior in design.
One of the reasons is that the rider is standing because a greater visibility
is required, but at the same time offers more resistance to the air and
does not keep his weight down, as he should. Nevertheless it is remarkable
that in Australia a sulky called "The Hittite Special" [Walsh]
was built according to a modified design derived from a Hittite chariot.
The rider was in a sitting position. This sulky performed very well and
astounding aspect of our comparison between ancient and modern vehicles is
the finding that the ratio track/wheel diameter is almost the same. The
Egyptian chariot, for those times, was really a masterpiece of
A real surprise was the discovery that the
average pressure on bearings is of the order of 30 kPa (that is 3 grams
per mm2). This value is low and also acceptable in modern mechanical
systems. It ensures a low consumption and deformation of the parts, and a
minimum bending moment of the ankle arm in the nave.