Title: Mechanics in 1337 B.C in the chariots of Egyptian Pharao Tut Ankh Amun.
Author: prof. Alberto Rovetta N. BO-1
References:

Tutankhamunís Tomb Series, Ed. J.R.Harris, Chariots and Related Equipment from the Tomb of Tutíankhamun by M.A. Littauer and J.H. Crouwel, Griffith Institute, Oxford, 1985.

Objectives
The main idea is that, in order to evolve, mankind - if stimulated by a high degree of cultural and spiritual energy - will invent suitable technologies, some of which prevail (while others disappear). If the level of civilisation is high, creativity and ingeniousness develop technologies in line with quality of life.

Contents
The unique scientific and technical principles of Pharaoh Tut Ankh Amunís chariots, remarkable for that time, consist of a combination of practical aspects with the design characteristics of the wheels, the naves, the bearings and the pole between the cart and the yoke. In fact, Pharaoh Tut Ankh Amunís chariots offer features of softness and comfort not unlike those of the most modern transportation carts. In fact, the wheels are flexible with respect to the body and offer a high degree of functionalism vis-a-vis bending and perturbations due to ground irregularities. The wheels are elastic because the rims and spokes are elastic thus offering a remarkable level of comfort during both slow and fast motion. The coupling between wheel and the axle is built with low friction, durable bearings. When the outer surface of chariot axles and the internal surface of the bearings are in wood, animal grease, which reduces friction and increases running duration, has been used. Chariots with wooden axles and internal hub surfaces covered by metal are more durable with increased mechanical resistance.
Some mechanical aspects of the structure of the wheels, the spokes, the materials chosen for the sleeve bearings, the use of animal grease for lubrication and the design of the chariot as a whole are extraordinary, being, in fact, very similar to some of the most modern technical and scientific principles used in machine mechanics today
Characteristics:

  1. Wheel structure elasticity to absorb uniformly the variable loads transmitted by soil irregularity so that the vibrations are damped by the wheel itself.
  2. Dynamic load, cleverly reduced due to the mediated friction effect of the grease, in order to ensure smooth, regular chariot motion.
  3. The concept that the symmetrical shape of the wheel spokes and division of the internal loads between the hub and the rim permit smooth motion, both at low and high speeds.
  4. Tribology and friction dynamics.
  5. Pivot support design concepts, with a long length in order to provide low flexibility to the sleeve and to accurately divide dynamic pressure during contact.

Results
From the infrared ray analysis conducted on the internal surfaces of the wheel hub and on the outer surface of the axle pivot, in correspondence to the sleeve bearing, Dr. Nasry Iskander determined that animal grease had been used.
In a similar calculation made with reference to Pharaoh Tut Ankh Amunís chariot, although the parameters are similar, differences with Ittite carts are substantially due to the effect of the spoke. In fact, the wheel spoke is built not with a rectilinear rod, with one single body, but in 2 parts, which are the columns of two different arcs. The wheel spokes of Pharaoh Tut Ankh Amunís chariots are formed by an arch of wood; each of the two sides contribute to forming one wheel spoke.

Future possible developments
The functionalism and mechanical efficiency of the chariots could be the result of a lucky series of technological coincidences (flexible wheels, compliant spokes, long hubs, friction surfaces between a hard body and a soft body to favor dynamic coupling and duration and center of gravity position close to the axles). The wheels are light, elastic and fit well against the ground. This is the first concept of a tyre ( i.e. an element that can be adapted to soil irregularities) at a time when the science of mechanics, the study of vibrations and of structure dynamics had no written basis, either from a technological or theoretical point of view. Nevertheless, such performance could be justified by scientific and technical results as studies of science of mechanics, even if theoretical studies on mechanics and on friction only assumed an organized structure through the use of scientific methods in the XIXth Century.