Tuesday, 17 September 2019 14:54

Production and maintenance of the triremes

Production and maintenance of the triremes

It has been said that in classical times Athens had a production capacity of at least 20 triremes per annum" - especially if an extra workforce from out of town could be encouraged to come to Athens. This figure, however, seems rather small considering the speed with which Agathocles, the Syracusans' general during the siege of Carthage, built (within a few weeks, probably) a triaconter which hastened back to Syracuse to inform his fellow citizens of the true war situation (Diodorus, 20.16.3).

Moreover, it seems that the Athenian state employed the services of specialized trireme-makers for each ship's construction and constant, meticulous maintenance. And although the bibliography has yet to arrive at a firm estimate of the cost of building a trireme at the time, the sum of one talent (about 6,000 drachmas) seems quite likely.

The triremes were so precious to the City that their maintenance was painstaking and costly, particularly at the shipyards where the vessels docked for repairs. The importance of these facilities was great enough for some commentator to compare their beauty to that of the Parthenon. 

Indeed, they seem to have been the target of attempted sabotage too, such as Antiphon's alleged attempt to set the dockyards on fire (346 BCE) on behalf of Philip (according to Demosthenes, "Against Stephanus", 132) or any attempted arson by Boeotians   imagined by Aristophanes   (Acharnians, 1000).

For maintenance purposes, the trireme could be dragged out of the water by its own oarsmen (170 in total): Weight ~ 40t, friction coefficient 0,20, required horizontal force 8t,   man's pushing/pulling   capacity ~ 50 kg, required number of men ~ 160 < 170. Major shipyards, however, are bound to have used winches.

  • It was highly necessary for the timber of triremes to be dried frequently (even during long expeditions), for the following reasons:

-Many types of timber were water-absorbent,  and thus added weight to the craft over time;

-Secondly, because after removing the barnacles from the hull, its retarring required a dry surface.

Moreover, a long sojourn in the sea increases the quantities of water that enter through the seams and remain in the hull, raising the ship's weight and displacement and proportionately reducing its speed. Thucydides complains that: "Our fleet was originally in first-rate condition: the ships were sound [... ], now, [... ] the timbers of the ships, having been so long exposed to the sea, are soaked", (7.12.3).

Too much dryness, however, is also harmful if the wood contracts to such an extent as to open the seams between the planks: "There was some apprehension about their own ships; for they had long been lain up and were not sea-worthy",   (Thuc. II.94).

  • In terms of construction, the docks where the triremes were repaired   are interesting in many different ways.

-They were preferably installed on rocky ground. The ramp over which the ship was drawn out of the water, and part of the underwater slide, was lined with transverse wooden beams ('sleepers')   packed-and possibly nailed- into grooves cut into the rock at intervals of about 0.80m in the case of Zea (Lovén 1.2, e.g. p. 76, D1.3). This reduced the overall kinetic friction of the keel at the "point" supports on the sleepers.

-The longitudinal gradient of the ramp is around 10% (Zea, Rhodes, Apollonia Cyrenaica) and up to 15% at Oiniadai (on the entrance to the Corinthian Gulf in western Acarnania). However, as the trireme was revered into the dock, the straight ramp is curved towards its end in order to support the upward-rising stem.

-The superstructure of the docks comprised longitudinal colonnades at intervals of approx. 6.50m and to a height of about 7.00m. Some colonnades were replaced by solid walls, most probably to prevent the spreading of fires.

-For obvious reasons, the preference was for enclosed, quasi-circular ports. Apart from a group of dock, Philo's Arsenal, the huge edifice for storing the various parts and equipment for the maintenance of triremes, was also located .at the port of Zea.

-Of this Arsenal, it is worth noting that (as we know from inscription EM12538 at the Epigraphic Museum of Athens) it was a building that measured 131x18x(13?)m, of impeccable internal organization and functionality. The technical specification for its construction makes provision for the ventilation necessary to keep the stored items dry: "In order that [sufficient] ventilation is made available in the toolshed, when the walls are built, the bricks should be occasionally displaced along the joints, as required by the architect" (line 92). And an important detail: "On both walls, shelf will be made, where the [ropes of] hypozomata will be lain", (line 74).

Now we understand Diodorus (14, 42.5) when, talking about Syracuse, he says that Dionysius built "one hundred and sixty costly shipsheds, most of which could accommodate two vessels [... ], the beholder was filled with utter wonder at the sight (14.43.1)" ...

And since transit gloria mundis, let us hear the tragic voice of Isocrates (Areopag. 66-67) when he accuses the Thirty Tyrants of having "sold for destruction for the sum of three talents the dockyards upon which the city had spent not less than a thousand talents". Of course, one could not help adhering to the terms of what was to the Athenians a shameful peace treaty imposed by the Lacedaemonians after the Peloponnesian War. The destruction of the shipyards was to Athens a loss more decisive than the demolition of the Long Walls.

Tassios T. P., On Technology In Ancient Greece, 2018 Angelakis, Athens

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