What are "hemiolii"?

[Jona Lendering]

In his account of the Roman attack on Carthage in 149 BCE, Appian mentions hemiolii. From the context, I deduce that these are ships - but what kind of ships exactly?

[Ildar]

J.Morrison. Hellenistic Oared Warships 399-31 BC in The Age of the Galley: Mediterranean Oared Vessels since Pre-Classical Times. Editors: R.Gardiner, J.Morrison. Edison, 2000, pp. 73-75:

Hemiolia [naus], hemiolios [lembos]

Invention

The first references to the light vessel which was usually called hemiolia is in Theophrastus [size=67:1tpr00v7]66[/size] in the first quarter of the fourth century, where the nervous passenger at sea is described as seeing a pirate hemiolia in every headland. There is also reference to a Carian hemiolia in a fragment of a fourth-century Attic orator preserved in the Etymologicum Magnum, [size=67:1tpr00v7]67[/size] and in Longus’s Daphnis and Chloe [size=67:1tpr00v7]68[/size] pirates from Tyre employ a Carian hemiolia. Since Carians were notorious pirates the connection with piracy in the eastern Mediterranean is the same. The hemiolia then naturally comes in Appian’s progressive list [size=67:1tpr00v7]69[/size] of pirate vessels illustrating the growth of their sea power with Mithridates’ encouragement: muoparones (ships with a single level of oars), hemioliai (ships with one and a half files of oars a side), dikrotoi (craft with two files of oars) and threes (ships with three files).

The evidence seems strong that the type, like the liburnian, was invented by pirates, probably in the eastern Mediterranean, probably also in Caria. The alternative hemiolioi lemboi, used once [size=67:1tpr00v7]70[/size] of thirty ships (distinguishing them from cataphracts and aphracts) in Philip V’s fleet against Scerdelaidas in 217 BC, suggests that the eastern type was introduced also to the Adriatic, probably under Macedonian influence.

Use

The hemiolia as a respectable naval vessel is attested in 346/345 BC (Diodorus [size=67:1tpr00v7]71[/size]: Phalaikos of Phocis), in 324 BC (Arrian [size=67:1tpr00v7]72[/size]: Alexander on the Hydaspes) and 315 BC (Diodorus [size=67:1tpr00v7]73[/size]: Agathocles). But when Arrian [size=67:1tpr00v7]74[/size] mentions Aristonikos of Methymna sailing into the harbour of Chios in 332/331 BC he calls his squadron ‘five pirate hemioliai’. Later Polyaenus [size=67:1tpr00v7]75[/size] speaks of Demetrius using them in 301 BC; and at the battle of Chios in 201 BC [size=67:1tpr00v7]76[/size] Philip employs a force of four fives, three hemioliai and other lighter ships to cut off Attalos’s flagship and drive it ashore. In the casualty list of the battle there are three hemioliai lost by Philip and one by Attalos. The most surprising mention of them is when, at the outbreak of he third Punic War in 149 BC, a Roman invasion fleet destined for Africa is said to contain 100 hemioliai listed together with the capital ships. Since the only function they can have had is as troop transports it seems that hemioliai is a general term which includes trihemioliai.

Oar system

Following the established type-naming principle, a hemiolia has one and a half files of oarsmen on each side of the ship as the trireme has three. The half-file, placed on each side of the gangway amidships, makes economical use of the broader beam amidships, adding power without a corresponding increase in weight of hull.

Design

There is no evidence for the design of the regular naval hemioliai since the number of oarsmen in each ship is not known. However, there is a clue to the size of Alexander’s hemioliai on the Indus in the fact that Ptolemy, whom Arrian quotes as one of his sources, seems to have included them in the overall category of triacontors, that is to say, oared warships with fifteen oarsmen a side. The oar system of these particular hemioliai could then have consisted of two full files of ten oarsmen and two half-files of five oarsmen seated amidships. There would then be on both sides three single-manned oars forward and two single-manned oars aft, while amidships there would be five pairs of oarsmen on each side rowing either alla sensile or a scaloccio, [size=67:1tpr00v7]77[/size] in both cases at one level.

Capability

Alexander in 336 BC built locally on the Hydaspes many triacontors and hemioliai as well as transports and supply ships. When the fleet began its voyage down river, Arrian quotes Ptolemy as saying that it consisted of 80 triacontors, together with horse transports, kerkouroi, and river boats. Ptolemy seems to have included the hemioliai among the 80 triacontors and Aristoboulos, Arrian’s main source, to have differentiated the hemioliai. At the meeting of the Hydaspes and Acerines the supply boats came through the rapids safely; but the oared warships, that is the triacontors, hemioliai and kerkouroi, were in difficulties since they were lower in the water. ‘All those that were dikrotoi having their lower oars not far above the waterline’ and two triacontors were in fact lost. Later [size=67:1tpr00v7]78[/size] Alexander took the fastest of the ships (the fastest of the hemioliai, all the triacontors and some kerkouroi) and continued the voyage.

If the half of the hemiolia oar system which occupied the middle half of the ship was rowed a scaloccio, the hemioliai were certainly not dikrotoi, nor if that half was rowed alla sensile were they such in the sense of the word dikrotoi as it applies to liburnians and fours. The conclusion to be drawn is that some of the triacontors, as might be expected, were in that sense dikrotoi, had their lower oarports close to the waterline so that two were flooded and lost. It was accordingly one of the virtues of the hemiolia to achieve a more favourable power/weight ratio than the ships with a single oar-level, without incurring the danger of flooding incurred by thalamian oarports.

It should be noted that in the list of the fastest ships the fastest of the hemioliai come first, then all the triacontors, followed by some of the remaining kerkouroi.
__________________________________
66. Theophrastus Characters 25.5.
67. Etymologicum Magnum 450.38.
68. Longus Daphnis and Chloe 1.28.
69. Appian Roman History 12.92.
70. Polybius 5.101.2.
71. Diodorus 16.61.4.
72. Arrian 6.1.
73. Diodoms 16.61.4.
74. Arrian Anabasis 3.2.3.
75. Polyaenus 4.7.4.
76. Polybius 16.6.4.
77. In the first of these oar systems, developed in Italy in the late Middle Ages, groups of 3-5 men sitting on benches placed on the galley’s deck in herring-bone pattern each pulled his own oar. In the second each group pulled a single great oar.
78. Arrian Anabasis 6.18.3.



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Below quote and diagram (fig. 73, p. 318) from Chapter 7 (written by J. Coates) of ancient oared warships Bible.

J.S. Morrison (with contributions by J.F. Coates). Greek and Roman Oared Warships 399-30 B.C. Oxford, 1996, pp. 317-319:

‘Ημιολία (ναυς) or ‘Ημιόλιος (λέμβος)

A number of arrangements of oarsystem have been proposed for ημιολίαι. The one offered here (72) would best fill the space available in the smallest, lightest and finest-lined hull able to accommodate 50 oarsmen within the topwale of the hull. It would be about 21 m on the waterline and displace about 14 tonnes. As in the case of the liburnian, the other small fast vessel discussed in this chapter, the wetted area of the hull should be minimised in any reconstruction. In the liburnian BWL is 3.0 m while in the ημιολία it could be reduced to 2.7 m: it may safely be assumed that BWL was as small as stability allowed. With that breadth, and a practical flare of the sides above water of say 25°, the breadth across the topwales of the hull cannot be greater than 3.75 m. If the necessary gangway is to be provided, outriggers are unavoidable in the ημιολία, owing to the necessary length and gearing of the oars and because the oarcrew are virtually at one level. BOA becomes 4.3 m. In the liburnian, on the other hand, no outriggers are necessary, and so a representation of a single level ship with indications of an outrigger may be suspected to be of a ημιολία.

In (73) all oars are worked by one man, but it is quite possible that the men sitting in the middle body of the hull, where there are two files, rowed two-man oars. Pirates in different places may have preferred one or the other system.

Wetted area would not be much less (5%) than in a liburnian with the same number of oars, so frictional resistance would be that much less too, but wavemaking at a given speed would be reduced also. Wavemaking forms a larger proportion of total resistance at higher speeds, so the finer and longer hull of the ημιολία would give it a speed advantage over the liburnian, and the very similar two-level pentecontor, particularly in a short race. It is not likely that ημιολίαι with many more than 50 crew would have been built because if longer, their hulls would have had to be stronger and so deeper and heavier, taking away the advantage of the greater oar power. The earlier single-level pente-contors must for the same reason have had hulls more capacious than was necessary only to accommodate their oarcrews. Alexander appears to have had ημιολίαι on the Indus with oarcrews of only 30 (p. 10), and they are stated to have been faster than his two-level ships with the same number of oars.



73 Hemiolia c. 300 BC

[Jona Lendering]

Wow, that's quite an answer. Not even Jasper could have done it better. Laudes, laudes, laudes.

[Robert Vermaat]

Thanks Ildar.