THE SHIELD OF AJAX

Ajax, son of Telamon, King of Salamis, and, according to Homer, a man of enormous stature and a colossal body, was inferior in strength and bravery only toAchilles. Ajax fought against Hector and, by the help of Athena, he saved Achilles΄body from the hands of the Trojans. Ajax lost in a contest with Odysseus for the possession of Achilles΄ panoply, and committed suicide. According to a later version, his disappointment led him to madness. When he recovered his senses, he committed suicide, by throwing himself on a sword that had been a present fromHector.

Ajax Telamonius was the patron hero of Salamis island, where a temple and a statue were erected in his honour, while Aianteia was an annual festivity. A town in Salamis is still called Aianteion.

Ajax participated in the Trojan War and the siege of Troy. He also possessed an extraordinary shield, described with great clarity in the Iliad, and sufficient details to perform a numerical simulation. Since the materials specified are not as expensive,as compared to the gold content of the shield of Achilles, and the construction much simpler, it was possible to produce specimens and perform an experimental study, to confirm analytical results and, in particular, to investigate the mechanism of energy dissipation of the impactor, which is radically different than the one of Achilles΄ shield. The Homeric description follows:

“Ajax came up bearing his shield in front of him like a wall- a shield of bronze with seven folds of oxhide- the work of Tychius, who lived in Hyle and was by far the best worker in leather. He had made it with the hides of seven full-fed bulls, and over these he had set an eighth layer of bronze”. (Iliad, 7, 219-223).

The battle behaviour of Ajax΄s shield during his duel with Hector is described in the sequence in the same book:

“He poised his spear as he spoke, and hurled it from him. It struck the sevenfold shield in its outermost layer- the eighth, which was of bronze- and went through six of the layers but in the seventh hide it stayed. Then Ajax threw in his turn, and struck the round shield of the son of Priam. The terrible spear went through his gleaming shield, and pressed onward through his cuirass of cunning workmanship; it pierced the shirt against his side, but he swerved and thus saved his life. They then each of them drew out the spear from his shield, and fell on one another like savage lions or wild boars of great strength and endurance: the son of Priam struck the middle of Ajax's shield, but the bronze did not break, and the point of his dart was turned.” (Iliad, 7, 224-259).

Hence, the shield is also a multi-layered structure, consisting of eight consecutive laminates, e.g., of a front laminate of hard bronze and seven layers of calf΄s leather.As shown in the sequence, both numerically and experimentally, the Homeric descriptions of the behavior of various shields in battle are confirmed with surprising accuracy and, once more, reveal elements of advanced scientific and technological knowledge.

Analysis of results

In this paragraph the impact of Hector΄s spear on Ajax΄s shield is analyzed. The same assumptions as with Achilles΄ shield were adopted, concerning shape and dimensions of spear and shield, and data from the modern javelin-throwing sport have been utilized.

Fig. 1 Finite Element discretization of thespear-shield system: The complete three-dimensional model (left) and a detail of spear-head (pike) and shield contact point (right)

Fig. 2 Impact behaviour of spear-shieldsystem, with all shield’s laminatespossessing the properties of bronze, at 4msec time after the beginning of the phenomenon, by which the spear pierces the shield.

It was assumed that the seven leather layers of the shield were of equal thickness, varying from 1 to 1.5 mm. With a circular shield and a spear hitting it at a direction normal to its surface, the problem is axisymmetric. The form of the generatrix of the shield cross section is elliptic with semi-axes 300 and 120 mm. Details of shield cross section and the spear head, as well as their 3-dimensional discretization, are given in Figs 1 and 2, concerning results for layers of bronze only(read also The shield of Achilles). Also, in Fig. 3, as an example, the results for onebronze laminate and four leather layers are given. In the present analysis, as the main factor of spear motion attenuation, the friction between the leather layers was considered, which in this case is the main mechanism to convert its kinetic energyinto heat.

Fig. 3 Penetration diagram of a simulated shield,

consisting of 1 bronze laminate and 4 leather layers.

Experimental

To test the penetration resistance, a series of specimens were manufactured,having the same multi-layer structure consisting of one laminate of hard bronze and a number of layers of calf leather. To investigate the mode of operation of the shield and of the spear penetration mechanism, various combinations of number and thickness of layers were examined. In fact, by maintaining the total thickness of leather layers constant, e.g., 7 mm, different forms of specimens, presented in Fig. 4 were experimentally tested. Τhe latter were impacted by hard bronze projectiles launched by an air-gun.

Fig. 4 Several specimen forms: Bronze laminate (red) is 1 mm thick, while total thickness for all leather layers (green) is 7 mm. There are: in (a) 2x3.5 mm leather layers, in (b) 2x2 mm+1x3 mm, in (c) 3x2 mm+1 mm and in (d) 7x1 mm. Specimen dimensions are 140x140 mm. Only specimen (d) resisted penetration.

The experimental setup appears in Fig. 5 (left) and consists of the air-gun, a specimen clamping jig and a system to measure projectile velocity. The air-gun has a compressed-air vessel and a barrel. (Designed by the late Professor Werner Goldsmith, University of California at Berkeley in 1981 during his sabbatical year in Patras.) The vessel is equipped with an electric detonation valve and a pressure gauge. The air-gun accepts barrels of different diameters and length. In this case, the barrel was 2 m long and had a diameter of 13.4 mm. Compressed-air was supplied by a central distribution line. The specimen clamping jig with part of the barrel appears in Fig. 5 (right).

Fig. 5 The air-gun (left) and a specimen clamping jig (right).

The air-gun shoots cylindrical projectiles with a conical tip made of bronze harder than shield bronze (Fig. 6, left). To measure the projectile velocity, a splitHe-Ne laser beam and two photodiodes with their respective outputs fed into a CRToscilloscope were used. The initial projectile velocity of a given mass projectile, again, corresponded to kinetic energy equal to that of the javelin of the year 2000 world champion, or 39.38 Joule. The photograph of a penetration hole appears on a bronze surface in Fig. 6 (right).

Fig. 6 The projectile before and after impact (left) and
a penetration hole on bronze surface (right).

Discussion of results and conclusions

A measure of the projectile penetration into the respective specimen is the size of the hole created on the surface bronze laminate (Fig. 6, right). Τhe results for the various specimens appear in Fig. 4. It is interesting that for the multi-layer shield with seven leather layers, i.e., Ajax΄s shield, penetration assumes a maximum value. However, this was the specimen that resisted penetration, and, in reality, was the last leather layer that eventually stopped the projectile. This agrees admirably with the Homeric description of its battle behaviour, stating that:

[Hector] “poised his spear as he spoke, and hurled it from him. It struck the sevenfold shield in its outermost layer- the eighth, which was of bronze- and went through six of the layers but in the seventh hide it stayed”. (Iliad, 7, 244-247).

Fig. 7 Penetration hole diameter on the surface of a bronze laminate against number of leather layers.

The bending of the projectile tip after a failed impact, shown in Fig. 6, is alsomentioned, e.g.:

“…the son of Priam struck the middle of Ajax΄s shield, but the bronze did not break, and the point of his dart was turned”. (Iliad, 7, 258-259).

With the shield of Ajax, the kinetic energy of the projectile is absorbed by the friction between the layers of leather, acting efficiently for a number of layers equal to or greater than seven and with sufficient deformation of the layers. On the other hand,a polynomial interpolation in the results of Fig. 7, shows that, for a greater number of leather layers, penetration tends to assume constant value. This proves that the structure described in the Iliad provides maximum resistance towards penetration, being also an optimum solution, since, for a greater number of layers, friction would be too strong and the structure too rigid to deform sufficiently and consume kinetic energy through friction. It is also noted that a small part of the projectile kineticenergy is absorbed by the deformation of the projectile tip, mentioned in Iliad 7,259and appears in Fig. 6.

Again, the hypothesis is confirmed, that the shield manufacturer (in this case, notHephaestus, a god, but Tychius, a simple tanner), was fully aware of the dynamic mechanical behaviour of multi-layered composite structures.

Dr S. A. Paipetis

Professor Emeritus, University of Patras

Dept. Mechanical Engng & Aeronautics

Ancient Greek City-States Standards

Introduction
In ancient times there were no flags. The Ancient Greeks in place of flags had shields bearing distinct and symbolic signs, which they called Episemon/Episema in plural (Standards), Parasemon/Parasema (Orders), Semeon/Semea (Marks or Signals), Mesomphalion/Mesomphalia (Shield Bosses) and through which they recognized their fellow-soldiers in battle. These signs were in the center of the shield. On their shields, they gave their military oath, and that oath-giving was a sacred ceremony*; The man who abandoned his shield was called Ripsaspis (he who abandons his shield, the recreant) and was disesteemed by all. The greatest dishonor was a shield fallen into the hands of the enemy (like today when the flag falls into the hands of the enemy). The Shield (Hoplon, meaning weapon), was made of wood, which was hollowed inside to allow for the soldiers to fit into it. The surface of the Hoplon was covered in bronze or leather or both and the design was painted or etched accordingly.


City-States Episema
Athens: The letter A (alpha, for Athens), or the owl (Glaphx, the owl was the symbol of goddess Athena the patron goddess of Athens) , or the Medusa's head (when Perseus killed Medusa, he dedicated her beheaded head to Athena's temple in Athens)

Sparta**: The most common Spartan Standard, the Greek letter Λ (Lamda) for Lacedaemon. Lacedaemon-Sparta's ancient name-was the capital of a south eastern region of the Peloponnese, called Laconia. Lacedaemon was the son of Zeus and Taygete, daughter of Atlas and Pleione. It was Lacedaemon who founded the city of Sparta, which was named after his wife. Sparta was often called Lacedaemon, as well, and the two names were often used interchangeably

The Royal Standard on the shield carried by the King. It probably symbolizes the Moon (the symbol of goddess Artemis , the patron goddess of the city)

The symbol of the Dioscuri, the Krotalon. Musical rattles normally consisting of tuned lengths of bone or hardwood suspended at one end from a hand-held frame and used by dancers in the worship of Dionysus and Kybele (Cybele) or the Dioscuri. A Greek letter Π, with two snakes (the Dioscuri) & the spider (the symbol of goddess Athena, the protectress of the Spartan Army). The Dioscuri were Castor and Polydeuces , the twin sons of Leda and Zeus and the brothers of Helen of Troy . Polydeuces was a formidable boxer, and Castor was a great horseman. The cult of the Dioscuri was indigenous of Sparta.

The Snake-Dragon of the Aegiads, a clan that had descendance from the Sparti people of Boeotia. Drakon (Dragon) was also the legendary primogenitor of Spartans

Arcadia: The letters AP (alpha-rho, for Arcadia)
Messenia: The letter M (mu, for Messenia)
Mantinea: The Trident (for Poseidon, the patron god of the city)
Corinth: The Pegasus (the winged horse of Greek myth, named for the Pegae , water-priestesses who tended the sacred spring in Pirene in Corinth)
Thebes: The Heracles' club (Heracles was Theban), the Boeotian shield, or the Sphinx (the monster sent by Hera to guard the pass to the city. Sphinx had the body of lion and the upper part of a woman), although the Thebans used individual shield designs most of times

Thespiae: The Crescent (the symbol of goddess Artemis , the patron goddess of the city)
Tegea: The letter T (tau, for Tegea)
Elis: The Eagle killing a snake (eagle was the symbol of Zeus , the patron god of Elis & Olympia)
Sicyon: The letter Σ (sigma, for Sicyon), or the Dove (the family arms of Sicyon of Attica who married Zeuxippe , daughter of king Lamedon , and became king of the city which was named after him)
Argos (the second oldest city of Greece): The Water Snake. Argive distintive feature was the Hydra (water-snake) symbol , which is associated with Argos after Heracles killed the water-snake at Lerna, near Argos

 Samos island: A facing lion's head. Lion was the symbol of Cybele , the goddess of motherhood, mountains and wild-beasts (worshipped in Samos)

Euboea island (except Eretria): The bull's or cow's head, for Euboea means "Island of Fine Cattle"
Eretria: A large Eye. Eretria was Athens' closest ally. The eye was one of Athenas' symbols
Thessaly: A bull's foot. Thessalians venerated god Dionysus, who was also hailed as "Axios Tauros" ("Worthy Bull")
Crete: A bull's head, one of Zeus' symbols. Zeus grew up in Crete
Epirus (especially the Molossi, the most prosperous Epirote tribe): The Standing Eagle, one of Zeus' symbols (the oracle of Dodone in Epirus , was the second most important oracle of antiquity, after Delphi, and the oldest.
The Delphi oracle was dedicated to Apollo;

 The Dodone oracle to Zeus, the father of the Gods)
Macedons: The Eagle (for Zeus), or the Macedonian 8 or 16-rayed Sun (the emblem of the first royal dynasty of Macedonia, the Argeads of Argos)

Rhodes island: A rose in bloom, which is a punning reference to the island's name
Syracuse (the largest Greek city of Magna Graecia): Described by Cicero as "the greatest Greek city and the most beautiful of them all", was founded by Greeks from Corinth & Tenea in the 8th century BC. The Triskelion or Trinakria was the symbol of Syracuse, alluding to Sicily's triangular shape. The Medusa in the center implies the protection of the Goddess Athena, the Patron Goddess of the Island

The Tarantines

The city of Taras or Tarantas (later called Tarentum or Taranto) was located on a strategic position controlling the rich trade routes to and from Italy and Greece.
During the Messenian war in 8th century BC, the Spartans decided to increase the numbers of their army, by adding into military service the sons of the unmarried Spartan women with the "perioikoi",who were not considered Spartan citizens. These soldiers were called 'Parthenioi', and despite their military service they were not granted citizenship, marked as potential troublemakers and were eventually forced to leave Sparta. Their leader, Phalanthos, went to Delphi to consult the oracle; the puzzling answer was that he would fulfill his mission only when it would rain on a clear day. Phalanthos did not at first understand the oracle, and continued his efforts to build a city in the most suitable place. However, after several battles with the barbarians he wasn’t successful in establishing the colony. As by definition it cannot rain on a fair day, Phalanthos grew concerned that the oracle intended for his people never to find a homeland. His wife, empathetic to Phalanthos' depression, tried to comfort him, but unable to restrain her tears, she wept on his face. At once Phalanthos explained the oracle and as night fell, he attacked and conquered the most prosperous coastal city in Apulia. The name of his wife was Aithra, which in Greek, translates to clear sky! The parthenian exiles founded in Apulia their city and named it Taras, after the son of the Greek sea god, Poseidon, and of a local nymph, Satyrion. According to other sources, Heracles founded the city and according yet to another myth, Taras is mentioned as the founder of the city; the symbol of the ancient city (as well as of the modern city) is Taras riding a dolphin. Taras increased its power, and rapidly became a rich, commercial power and a sovereign city of Magna Graecia, ruling over the Greek colonies in southern Italy.
Taras was the only Lacedaimonian colony, but their culture and armies were not based only to the Lacedaimonian standards. Like most of the Hellenic factions of Magna Graecia, they borrowed elements from neighbouring native cultures. At its founding, Taras was a monarchy, likely modelled on that of Sparta; according to Herodotos, around 492 BC king Aristophilides ruled over the city. The expansion of Taras was limited to the coast because of the resistance of the local populations of inner Apulia. In 472 BC, Taras signed an alliance with the city-colony of Rhegion, to counter the Messapi, Peuceti, and Lucanians, but the joint armies of the Tarentines and Rhegines were defeated near Kailia, in what Herodotus claims to be one of the greatest slaughter of Greeks in his knowledge, with 3,000 Reggians and uncountable Tarentines killed. In 466 BC, Taras was again defeated by the Iapyges; according to Aristotle, there were so many aristocrats killed, that the democratic party was able to seize power, overthrow the monarchy, inaugurate a democracy and expel the Pythagorians. However, the rise of the democratic party did not weaken the bonds of Taras and her mother-city Sparta. In fact, Taras supported the Peloponnesian side against Athens in the Peloponnesian Wars, refused anchorage and water to Athens in 415 BC, and even sent ships to help the Peloponnesians, after the Athenian disaster in Sicily. Athens on the other hand, seeking to counter Taras' influence in Magna Graecia, supported the enemies of Taras, the Messapians.

 In 432 BC, after several years of war, Taras signed a peace treaty with the Greek colony of Thurioi; both cities then contributed to the foundation of the colony of Heraclea, which rapidly fell under Tarantine control. Despite the constant threat of native populations, Carthagianian and Etruscan assaults, Taras managed to reach its peak of power and wealth; it was the most important city of Magna Graecia and the main commercial port of southern Italy controlling the trade routes to and from Hellas. Taras produced and exported goods to and from motherland Greece, it had the largest army and fleet in southern Italy. However, with the death of Archytas in 347 BC, the city started a slow, but steady decline; the first sign of the decreased power was its inability to field an army, since the Tarantines preferred to use their substantial wealth to hire mercenaries, rather than leave their lucrative trades.
In order to defend their city against the numerous barbarians and force the rest of the Greeks of Magna Graecia in the southern part of Italy, to stay under their political and economical influence, the Tarantines made alliances with several Hellenic factions of Magna Graecia, including the Syracusians. Across the sea, they were also allied with the Lacedaimonians and the Epirots. Their last call for help against the growing might of the Romans, put Roma itself under a great threat, when the Epirot king Pyrrhus, found the opportunity to go on the offensive, but eventually both Pyrrhus and the Tarantines lost the war, their defensive walls were demolished and all their efforts to maintain their independence failed.
Playing with the Tarantines you will need to focus on one front; either face the barbarians and expand towards the interior or try to become the hegemon of the colonies of Magna Graecia. You would also be wise to keep an eye out for any possible invasions by the Epirotes and Illyrians from across the sea...

*The Ancient Athenian Hoplite, while holding the hoplon, the City was entrusting with him and appointing him defender of the democratic institutions of Athens, took this oath:
" shall not bring dishonour on my sacred arms nor will I abandon my comrade wherever I shall be stationed;
I shall defend the rights of Gods and men by myself and with the help of others;
I shall never bring disgrace on this our City by an act of dishonesty or cowardice;
I shall fight for the ideals and Sacred Things of the City both alone and with many;
I shall revere and obey the City's laws, and shall do my best to incite a like reverence and respect in those above me who are prone to annul them or set them at naught.
I shall strive increasingly to quicken the public's sense of civic duty.
Thus in all these ways I shall transmit this City, not only not less, but greater and more beautiful than it was transmitted to us.
I shall believe in the gods of my country;
I shall revere my City's sacred institutions.
Gods are my witnesses:
Agravlos, Enyalios, Aris, Zeus, Thallo, Aphxo, Hegemone"

**Spartans fought like every other ancient Greek hoplite unit. However, one could say that the Sciritae (an elite unit of Spartan troops descended from Sciritis, a Highland region of the central Peloponnese between Laconia and Arcadia, close to the border with Tegea; they were probably perioikoi, who formed a corps of specialized infantry of the Spartan army, known as Sciritis Lochos (Lochos/ΛΟΧΟΣ-a unit of the Spartan army, roughly comparable to a battalion or regiment, commanded by a lochagos) would fit the characteristics of a "specialised" force. Their duties included scouting, marching at the head of the Spartan Column and taking up posts outside the camp to watch for intrusions.

Sciritis contributed some 600 men to the Lacedemonian army, they fought at the extreme right of the army (others say they occupied the honorary left wing of the army), they were able to run fast and intercept peltasts but they carried a Hoplon which allowed them to fight in phalanx formation if the need would arrise. Xenophon describes their actions at Tanagra (377 BC) as taking to the hill (with the cavalry) that the Boeotians had retired from upon and attacking the Boeotians from the rear.