Editing Trireme (section)

==Design==
[[File:Model of a greek trireme.jpg|thumb|Model of a Greek trireme]]
[[File:Romtrireme.jpg|thumb|A [[Roman mosaic]] from [[Tunisia]] showing a trireme vessel during the [[Roman Empire]]]]
Based on all archeological evidence, the design of the trireme most likely pushed the technological limits of the ancient world. After gathering the proper timbers and materials it was time to consider the fundamentals of the trireme design. These fundamentals included accommodations, propulsion, weight and waterline, centre of gravity and stability, strength, and feasibility.  All of these variables are dependent on one another; however a certain area may be more important than another depending on the purpose of the ship.<ref name="JC2"/>

The arrangement and number of oarsmen is the first deciding factor in the size of the ship. For a ship to travel at high speeds would require a high oar-gearing, which is the ratio between the outboard length of an oar and the inboard length; it is this arrangement of the oars which is unique and highly effective for the trireme.  The ports would house the oarsmen with a minimal waste of space.  There would be three files of oarsmen on each side tightly but workably packed by placing each man outboard of, and in height overlapping, the one below, provided that thalamian tholes were set inboard and their ports enlarged to allow oar movement.  
Thalamian, zygian, and thranite are the English terms for ''{{lang|grc-Latn|thalamios}}'' ({{lang|grc|θαλάμιος}}), ''{{lang|grc-Latn|zygios}}'' ({{lang|grc|ζύγιος}}), and ''{{lang|grc-Latn|thranites}}'' ({{lang|grc|θρανίτης}}), the Greek words for the oarsmen in, respectively the lowest, middle, and uppermost files of the triereis.  
The holes were pins that acted as fulcrums to the oars that allowed them to move.  The center of gravity of the ship is low because of the overlapping formation of the files that allow the ports to remain closer to the ships walls.  A lower center of gravity would provide adequate stability.<ref name="JC2"/>

The trireme was constructed to maximize all traits of the ship to the point where if any changes were made the design would be compromised.  Speed was maximized to the point where any less weight would have resulted in considerable losses to the ship's integrity.  The center of gravity was placed at the lowest possible position where the Thalamian tholes were just above the waterline which retained the ship's resistance to waves and the possible rollover. If the center of gravity were placed any higher, the additional beams needed to restore stability would have resulted in the exclusion of the Thalamian tholes due to the reduced hull space.  The purpose of the area just below the center of gravity and the waterline known as the ''{{lang|grc-Latn|hypozomata}}'' ({{lang|grc|ὑποζώματα}}) was to allow bending of the hull when faced with up to 90&nbsp;kN of force.  The calculations of forces that could have been absorbed by the ship are arguable because there is not enough evidence to confirm the exact process of jointing used in ancient times.  In a modern reconstruction of the ship, a polysulphide sealant was used to compare to the caulking that evidence suggests was used; however this is also contentious because there is simply not enough evidence to authentically reproduce the triereis seams.<ref name="WF1"/>

Triremes required a great deal of upkeep in order to stay afloat, as references to the replacement of ropes, sails, rudders, oars and masts in the middle of campaigns suggest.<ref name="Hanson260">Hanson (2006), p. 260</ref><ref name=Fields10>Fields (2007), p. 10</ref> They also would become waterlogged if left in the sea for too long. In order to prevent this from happening, ships would have to be pulled from the water during the night. The use of lightwoods meant that the ship could be carried ashore by as few as 140 men.<ref name="IG153">''[[Inscriptiones Graecae|IG]]'' I.153</ref> Beaching the ships at night, however, would leave the troops vulnerable to surprise attacks. While well-maintained triremes would last up to 25 years, during the Peloponnesian War, Athens had to build nearly 20 triremes a year to maintain their fleet of 300.<ref name="Hanson260"/>

The Athenian trireme had two great cables of about 47&nbsp;mm in diameter and twice the ship's length called ''hypozomata'' (undergirding), and carried two spares. They were possibly rigged fore and aft from end to end along the middle line of the hull just under the main beams and tensioned to 13.5 tonnes force. The ''hypozomata'' were considered important and secret: their export from Athens was a capital offense.<ref>{{cite web| url = http://www.soue.org.uk/souenews/issue5/jenkinlect.html| title = The 18th Jenkin Lecture, 1 October 2005: Some Engineering Concepts applied to Ancient Greek Trireme Warships}}</ref> This cable would act as a stretched tendon straight down the middle of the hull, and would have prevented [[Hogging and sagging|hogging]]. Additionally, hull plank butts would remain in compression in all but the most severe sea conditions, reducing working of joints and consequent leakage.<ref>{{cite web| url = http://ina.tamu.edu/library/tropis/volumes/1/Coats,%20John%20-%20The%20trieres,%20its%20design%20and%20construction.pdf| title = Proceedings of 1st INTERNATIONAL SYMPOSIUM ON SHIP CONSTRUCTION IN ANTIQUITY PIRAEUS, 30 AUGUST – 1 SEPTEMBER 1985: THE TRIERES, ITS DESIGN AND CONSTRUCTION}}</ref> The ''hypozomata'' would also have significantly braced the structure of the trireme against the stresses of ramming, giving it an important advantage in combat.<ref>{{cite web| url = https://archive.org/stream/shipswaysofother00chatrich/shipswaysofother00chatrich_djvu.txt| title = SHIPS & WAYS OF OTHER DAYS, BY E. KEBLE CHATTERTON| year = 1913}}</ref> According to material scientist [[J.E. Gordon]]: "The ''hupozoma'' was therefore an essential part of the hulls of these ships; they were unable to fight, or even to go to sea at all, without it. Just as it used to be the practice to disarm modern warships by removing the breech-blocks from the guns, so, in classical times, disarmament commissioners used to disarm triremes by removing the ''hupozomata''."<ref name=gordon>{{cite book |last= Gordon |first= J. E. |author-link= J.E. Gordon |title= Structures, or why things don't fall through the floor |date= 1978 |publisher= Pelican Books |isbn= 0-306-81283-5}}</ref>

===Dimensions===
Excavations of the ship sheds (''neōsoikoi'', νεώσοικοι) at the harbour of Zea in [[Piraeus]], which was the main war harbour of ancient Athens, were first carried out by Dragatsis and [[Wilhelm Dörpfeld]] in the 1880s.<ref>[http://www.rgzm.de/Navis2/Home/HarbourFullTextOutput.cfm?HarbourNR=Piraeus Piraeus: Cantharus, Zea, Munichia] {{Webarchive|url=https://web.archive.org/web/20070830035442/http://www2.rgzm.de/Navis2/Home/HarbourFullTextOutput.cfm?HarbourNR=Piraeus |date=30 August 2007 }}, from the Römisch-Germanisches Zentralmuseum of Mainz</ref> These have provided us with a general outline of the Athenian trireme. The sheds were ca. 40 m long and just 6 m wide. These dimensions are corroborated by the evidence of [[Vitruvius]], whereby the individual space allotted to each rower was 2 [[cubits]].<ref>Vitruvius, ''De architectura'' I.2.4</ref> With the Doric cubit of 0.49 m, this results in an overall ship length of just under 37 m.<ref>Fields (2007), p. 8</ref> The height of the sheds' interior was established as 4.026 metres,{{Citation needed|date=October 2007}} leading to estimates that the height of the hull above the water surface was ca. 2.15&nbsp;metres. Its [[Draft (hull)|draught]] was relatively shallow, about 1&nbsp;metre, which, in addition to the relatively flat keel and low weight, allowed it to be beached easily.{{Citation needed|date=October 2007}}

===Construction===
[[File:Mortise tenon joint hull trireme-en.svg|thumb|The mortise and tenon joint method of hull construction employed in ancient [[marine vessel|vessels]].]]
Construction of the trireme differed from modern practice. The construction of a trireme was expensive and required around 6,000 man-days of labour to complete.<ref>Hanson (2006), p. 262</ref> The ancient Mediterranean practice was to build the outer [[hull (watercraft)|hull]] first, and the ribs afterwards. To secure and add strength to the hull, cables (''hypozōmata'') were employed, fitted in the keel and stretched by means of [[windlass]]es. Hence the triremes were often called "girded" when in commission.<ref>Fields (2007), p. 9</ref>

The materials from which the trireme was constructed were an important aspect of its design. The three principal timbers included fir, pine, and cedar. Primarily the choice in timber depended on where the construction took place. For example, in Syria and Phoenicia, triereis were made of cedar, because pine was not readily available.  Pine is stronger and more resistant to decay, but it is heavy, unlike fir, which was used because it was lightweight. The frame and internal structure would consist of pine and fir for a compromise between durability and weight.<ref name="JC2"/>

Another very strong type of timber is oak; this was primarily used for the hulls of triereis, to withstand the force of hauling ashore.  Other ships would usually have their hulls made of pine, because they would usually come ashore via a port or with the use of an anchor. It was necessary to ride the triereis onto the shores because there simply was no time to anchor a ship during war and gaining control of enemy shores was crucial in the advancement of an invading army. (Petersen) The joints of the ship required finding wood that was capable of absorbing water but was not completely dried out to the point where no water absorption could occur. There would be gaps between the planks of the hull when the ship was new, but, once submerged, the planks would absorb the water and expand, thus forming a watertight hull.<ref name="JC2"/>

Problems would occur, for example, when shipbuilders would use green wood for the hull; when green timber is allowed to dry, it loses moisture, which causes cracks in the wood that could cause catastrophic damage to the ship. The sailyards and masts were preferably made from fir, because fir trees were naturally tall, and provided these parts in usually a single piece. Making durable rope consisted of using both papyrus and white flax; the idea to use such materials is suggested by evidence to have originated in Egypt. In addition, ropes began being made from a variety of [[esparto]] grass in the later third century BC.<ref name="JC2"/>

The use of light woods meant that the ship could be carried ashore by as few as 140 men,<ref name="IG153"/> but also that the hull soaked up water, which adversely affected its speed and maneuverability. But it was still faster than other warships.

[[File:Trireme Ram.jpg|thumb|Bronze trireme ram]]
Once the triremes were seaworthy, it is argued that they were highly decorated with, "eyes, nameplates, painted figureheads, and various ornaments". These decorations were used both to show the wealth of the patrician and to make the ship frightening to the enemy. The home port of each trireme was signaled by the wooden statue of a deity located above the bronze ram on the front of the ship.<ref name="Hanson239">Hanson (2006), p. 239</ref> In the case of Athens, since most of the fleet's triremes were paid for by wealthy citizens, there was a natural sense of competition among the patricians to create the "most impressive" trireme, both to intimidate the enemy and to attract the best oarsmen.<ref name="Hanson239"/> Of all military expenditure, triremes were the most labor- and (in terms of men and money) investment-intensive.

===Propulsion and capabilities===
The ship's primary propulsion came from the 170 oars (''kōpai''), arranged in three rows, with one man per oar. Evidence for this is provided by Thucydides, who records that the [[Ancient Corinth|Corinthian]] oarsmen carried "each his oar, cushion (''hypersion'') and oarloop".<ref>Thucydides, II.93.2</ref> The ship also had two masts, a main (''histos megas'') and a small foremast (''histos akateios''), with square sails, while steering was provided by two steering oars at the stern (one at the port side, one to starboard).

Classical sources indicate that the trireme was capable of sustained speeds of around {{convert|6|knots|km/h mph|lk=in}} at relatively leisurely oaring.<ref>The Age of the Galley, pp. 58–59</ref> There is also a reference by Xenophon of a single day's voyage from [[Byzantium]] to [[Heraclea Pontica]], which translates as an average speed of {{convert|7.37|knots|km/h mph}}.<ref>The Age of the Galley, p. 58</ref> These figures seem to be corroborated by the tests conducted with the reconstructed ''[[Olympias (trireme)|Olympias]]'': a maximum speed of {{convert|8|knots|km/h mph}} and a steady speed of {{convert|4|knots|km/h mph}} could be maintained, with half the crew resting at a time.<ref>Adrian Goldsworthy, ''The Fall of Carthage: The Punic Wars 265–246 BC'', Cassell 2003, p. 98</ref> Given the imperfect nature of the reconstructed ship, as well as the fact that it was manned by totally untrained modern men and women, it is reasonable to suggest that ancient triremes, expertly built and navigated by trained men, would attain higher speeds.

The distance a trireme could cover in a given day depended much on the weather. On a good day, the oarsmen, rowing for 6–8 hours, could propel the ship between {{convert|80-100|km}}. There were rare instances, however, when experienced crews and new ships were able to cover nearly twice that distance (Thucydides mentions a trireme travelling 300 kilometres in one day).<ref>Hanson (2006), p. 261</ref> The commanders of the triremes also had to stay aware of the condition of their men. They had to keep their crews comfortably paced, so as not to exhaust them before battle.