Ancient Port Structures

The main elements of a port are its breakwater(s) to reduce wave action inside a protected basin, where quays or jetties, with some mooring devices, are available for loading/unloading ships. Hence, a breakwater and a quay have to be built using available construction materials and methods, and a basin has to be dredged and maintained at adequate depth.

The oldest known port structure (in 2016) is the Wadi el-Jarf breakwater in the Gulf of Suez (ca. 2570 BC, Khufu-Khéops, IVth Dynasty). This structure is ca. 325 m long and ca. 6 m wide. It is made of cobbles and clay[1]. The port of Byblos (Lebanon) is from the same period, but it is located inside a natural cove with no known port structures[2].

Anchorages more or less sheltered by offshore ridges were used on the Levantine coast in the Middle Bronze Age (2100-1550 BC): Arwad, Beirut, Sidon, Sarepta, Tyre. In Yavne-Yam (Israel) submerged boulders may have been used to improve the shelter[3].

The very large port on Pharos island might also date from this period and its more than 2 km long main breakwater might be seen as an ancestor of the typical Phoenician breakwater structure with two ashlar vertical walls with interspace filled with rubble[12].

The next oldest port structure is the Sidon North breakwater (ca. 1700-1500 BC), which is 230 m long with large headers up to 5 m long[7],

At Kommos (Crete) a shipshed located at some distance from the coast, and including 6 galleries of 37 x 5.60 m, is dated Late Minoan (ca. 1400 BC)[4].

Next are the following ports, all located in ancient Phoenicia:

  • Late Bronze Age:
    • Dor (Israel, ca. 1200 BC) with a shallow water quay, 35 m long made of large 1 x 1 x 3 m ashlar headers facing the sea[5],
  • Phoenician Period:
    • Athlit breakwater (Israel, ca. 800 BC, 130 x 10 m)[6],
    • Tabbat el-Hammam breakwater (Syria, ca. 800 BC, 160 x 8 m)[8].

The two latter breakwaters are made of ashlar headers 0.5-0.7 x 0.5-0.7 x 1-2 m. These early breakwaters consist of two ashlar vertical walls with interspace filled with rubble. However, this type of structure was still in use much later in the 3rd c. BC (e.g. Tyre[9], 90 x 13 m with 2 m headers, and Amathous in Cyprus[10] 380 m with 3 m headers).

The Samos breakwater (ca. 530 BC) described by Herodotus (Hist, 3, 44-60) is 480 m long, consisting of a rubble mound. This type of structure was widely used for breakwaters in water depths deeper than a few meters where positioning of ashlar headers by divers was difficult. This construction method was described later on by Pliny the Younger at Centumcellae (103 AD). The largest ancient breakwater of this type is at Portus Claudius (ca 60 AD, more than 3200 m for both breakwaters). This construction method is still used very often nowadays.

A major evolution was the introduction of ‘Puteolanus pulvis’ (often translated by ‘pozzolana’) for hardening concrete under water. This enabled large blocks of hundreds of cubic meters of concrete to be constructed under water by means of pouring concrete into prefabricated wooden caissons. The first known use is at Agrippa’s naval base of Portus Iulius, near Pozzuoli, in 37 BC, and the most famous is at Caesarea Maritima (Israel) built between 22 and 10 BC[11]. Also this construction method is still used by modern engineers.

Some of these breakwaters have been luckily preserved and survived 2000 years of wave attack, but most of the ancient breakwaters were destroyed by wave action and remains are found under water as “submerged breakwaters”. Careful examination of historical Google Earth images enables us to see quite a few breakwater remains in shallow waters.
As the process of destruction of breakwaters by waves was not all that clear, further analysis was undertaken by the author, focussed on the worst possible wave conditions, considering that they will eventually occur in the long term. In other cases, an approach based on a “design wave” must be used.

Vitruvius‘s “de Architectura” dated around 20 BC, is the only ancient text left about maritime construction methods. Unfortunately, no drawings  are available, so that his descriptions are not all that clear to us. The three of his methods are considered here in some detail with help of various sketches prepared by previous architects and engineers.
See: OLESON, J. et al. “Building for Eternity”, 2014 .
See also: http://www.romanconcrete.com/romanconcrete.htm .

A question might be asked why the ancient engineers did not invent reinforced concrete, e.g. by means of chains placed inside the mortar. As steel is subject to corrosion and therefore to increase of its volume, that induces cracking of the concrete, the ancients may not have found it such a good idea (NB: the oldest modern reinforced concrete structures are around one century old and are not in a good condition today, e.g. Tour Perret in Grenoble, France). Another part of the answer might be that as the ancients had vaults, they did not use overhanging structures that require reinforced concrete. However, massive structures like walls and towers needed to be reinforced at their base in order to provide internal cohesion. It appears that courses of bonding tiles were used for this purpose. It can be shown from available testing results that the initial shear strength of lime mortar on tiles and bricks is somewhat larger than on natural stones. Hence, each course of tiles placed inside the stone masonry acts like a modern tie beam made of reinforced concrete.

Silting-up of harbours was always a major concern and that is still the case for modern port engineers. One should remember that waves are the driving force of the so called “littoral drift” (transport of sand along the coast). As the aim of breakwaters is to reduce wave penetration into the port, sand will settle down. Hence structures including arches are not efficient to stop waves while letting sand passing through. That simply does not work!

Pierced stones can be used as mooring devices when the hole has a horizontal axis. Holes with a vertical axis are believed to be used for derricks like those used onboard ships.

[1] Pierre Tallet, 2015: http://www.orient-mediterranee.com/spip.php?article3017: Khufu-Khéops is therefore a precursor, not only for his Great Pyramid, but also for his maritime works.

[2] Nicolas Carayon, 2011: Geoarchaeology of Byblos, Tyre, Sidon and Beirut, Rivista di Studi Fenici 1 2011_Impaginato 30/06/12 14:52, pp 45-55.

[3] Nick Marriner et al, 2017: Harbors and Ports, Ancient, in Encyclopedia of Geoarchaeology, ed. Springer Science+Business Media Dordrecht, pp 382-403.

[4] David Blackman & Boris Rankov, 2013: Shipsheds of the Ancient Mediterranean, Cambridge University Press, p 10.

[5] Avner Raban, 1987: The Biblical Archaeologist, Vol. 50, No. 2. (Jun., 1987), pp. 118-126.

[6] Arad Haggi, 2005 : Underwater excavation at the Phoenician harbor at Athlit, 2002 season, R.I.M.S. News, report N° 31, Haifa, 2005

[7] Nicolas Carayon, 2012: Les ports phéniciens du Liban – Milieux naturels, organisation spatiale et infrastructures, Archaeology and History in Lebanon, 36-37 (2012-2013), p. 1-137.

[8] Robert Braidwood, 1940: Report on two sondages on the coast of Syria, south of Tartous “. In: Syria. Tome 21 fascicule 2, 1940. pp. 183-226

[9] Ibrahim Noureddine, 2010 : New Light on the Phoenician New Light on the Phoenician Harbor at Tyre, Near Eastern Archaeology 73:2–3 (2010)

[10] Navis II Project: http://www2.rgzm.de/navis2/home/FramesE.cfm

[11] Chris Brandon, 2014: Building for Eternity – The history and Technology of Roman Concrete Engineering in the Sea, Oxbow Books.

[12] Gaston Jondet, (1916) ‘’Les ports submergés de l’ancienne île de Pharos’’, Mémoires présentés à l’institut égyptien, Tome IX, Le Caire, (121 p).
Leopold Savile, (1940), Presidential address of Sir Leopold Halliday Savile, K.C.B. on 6/11/1940, Journal of the institution of Civil Engineers 15, No 1, November 1940, (pp 1-26).
Raymond Weill, (1916) “Les ports antéhelléniques de la côte d’Alexandrie et l’Empire crétois’’, Bulletin de l’Institut Français d’Archéologie Orientale, Tome XVI.

Some definitions of ancient Greek terms:

NB: these are no more than the most probable (and schematic) definitions!
Some are described in:

KOWALSKI, JM. (2012) « Navigation et Géographie dans l’antiquité Gréco-Romaine – La terre vue de la mer », éd. Picard, Paris.

ARNAUD, P. (2015) « Entre mer et rivière : les ports fluvio-maritimes de Méditerranée ancienne », Colloque ‘Les ports dans l’espace méditerranéen antique. Narbonne et les systèmes portuaires fluvio-lagunaires’, Espace Capdeville, Montpellier 22/23 mai 2014.

Ports and harbours:
Porthmos, Stenon (Latin: fretum; FR: chenal; GB: channel): navigable route in a narrow sea way, usually with buoyage.
Chantaki (Latin: fossa; FR: canal; GB: canal): artificial waterway for navigation or irrigation.
Ankyrobolion (Latin: statio; FR: mouillage peu profond ; GB: shallow anchorage): shallow anchorage preferably on sandy bottom providing good holding for anchors.
Limen (Latin: portus, statio; FR: rade, havre, abri; GB: roadstead, harbour): sheltered area for ships, in most weather conditions.
Hormos, Ormos  (Latin: portus; FR: port; GB: port): sheltered basin where ships can load and unload in all weather conditions. A good port will enable operations independently of wave and current conditions.
Epineïon (Latin: portus; FR: port; GB: port): port disconnected from the city and used for war ships (e.g. Piraeus/Athens and Ostia/Rome).
Naustathmos (Latin: navale; FR: base navale; GB: naval base, naval station): harbour for war ships.
Limen kleistos (Latin: portus; FR: port fermé; GB: closed port): intra-muros port connected to the city, protected by the city walls and by a chain at the port entrance.
Cothon, Kothon (Latin: cothone; FR: cothon; GB: cothon): used since antiquity to refer to the circular port of Carthage. Nowadays, the specialists of harbour archaeology agree that this term can be associated to a dug harbour-basin of any shape connected to the sea through a channel (Carayon, 2005).
Emporion (Latin: emporio; FR: ville portuaire; GB: port of trade): maritime city with commercial port and trade facilities.
Choma, Teichos (Latin: moles; FR: jetée; GB: jetty): massive vertical structure built out into the sea (see Strabo, Geogr. 5.4.6 describing the Puteoli arched moles as a ‘chomata’). The word ‘mole’ is still used both in FR and GB by archaeologists for a massive structure separating two bodies of water, like a breakwater, a jetty or a causeway.
Prokumaia (Latin: moles; FR: brise-lames; GB: breakwater): massive structure built out into the sea to protect a port from wave attack (see Flavius, Jewish War 1.412 & Jewish Ant. 15.334 describing the Caesarea mole: a distinction is made between the seaside part as a ‘Prokumaia’ – breakwater and the portside as a ‘teichos’- wall).
Apovathra (Latin: xxxx; FR: appontement, débarcadère; GB: wharf, landing stage; US: pier, landing stage): structure to load and unload ships, usually on piles (e.g. finger pier).
xxxxxxx (Latin: xxxx; FR: appontement; GB: pier): wharf with light structure, typically used for walkways and pleasure piers.
xxxxxxx (Latin: xxxx; FR: darse, bassin portuaire; GB: dock, harbour basin): enclosed area of water used for loading, unloading, building or repairing ships.
Diolkos (Latin: clivum?; FR: cale de halage; GB: slipway, ways): ramp sloping toward the water on which boats can be hauled in and out of the water.
Neorion, Neoria (Latin: navale, navalia; FR: arsenal, chantier naval; GB: dockyard, shipyard): place for ship building and repair
Nesoikos, Neosoikoi (Latin: navale, navalia; FR: loge, hangar à bateau; GB: shipshed, boathouse): shed for sheltering a boat, usually built partly over water.
No Greek word (Latin: carbunculo; FR: béton hydraulique; GB: hydraulic concrete): is made by replacing some of the cement in a concrete mix with activated aluminium silicates (pozzolanas such as fly ash) to activate cement setting in wet condition or underwater and further protect hardened concrete from chemical attack.
No Greek word (Latin: arca; FR: batardeau; GB: cofferdam): watertight structure, usually made of sheet piling, that encloses an area under water that can be pumped dry, in order to enable construction work to be carried out “in the dry”.