Because they obstruct navigation, floating bridges are limited in nonmilitary applications, yet several long-span floating bridges have been built in modern times. During this time, the army waiting at the shore would have got into a very serious situation, since the provisions of food, fodder and water had not been calculated to cope with a prolonged stay. [27] The other bridge consisting of 360 ships in a similar configuration would then have a length of near to 2,520 m (2,760 yd), which appears reasonable for a bridge situated some distance to the northeast of Nagara Point. The lowest oar ports of a trireme were about 30 cm above the waterline and were normally fitted with leather sleeves,[18] an aspect which does not really qualify them as a bridge carrier. Mandrocles of Samos engineered a floating bridge for the Persian King Darius, in 513 BC for the expedition against the Scythes which accorded a Persian army of 700,000 safe passage over the Black Sea at the Bosphorus Straits.. The idea of the cables having been produced on the ships already lined up for the bridge[36] does not appear to be feasible, either. Hammonds (p.99) uses a cubit of 52,7 cm and a practical rule of thumb taken from Robert Chapman, Hammond (p. 101) describes the mooring by way of an. Sailors carefully prevent ropes from chafing or from being pressed by hard objects and thus try to avoid early deterioration of the ropes. Even if iron anchors existed already then,[22][23] it is unlikely that the iron manufacturing was capable to produce some 183 tonnes of iron anchors. A canal crossing the Athos peninsula was constructed. In addition, the anchorage is not safe: the long ropes cannot prevent the ships from swinging and colliding, in particular when eddies add to the confusion and long ropes get entangled. However, upon closer examination, almost every detail of the bridges is the subject of discussions, doubts and questions. [49] When winds caused the load on the cables to increase the triremes would have been pushed deeper into the water but this was only temporary as long as the wind lasted. Wooden planks were laid across the cables, and brushwood and soil used to cover the planks and form a dirt roadway. Barker, p. 30; Hammond, p. 93 in the little chart, Barker (p. 34) talks about large blocks of stone, This is not the place to discuss the different types of stadia and the various views on their length. Because of the current and the lateral wind forces, they would have described a large curve allowing for a sort of horizontal sag of the cables in order to prevent the tension to increase indefinitely. It is left to speculation whether and to what extent ships, cables, ropes and logs were recovered, saved, repaired and reused. One may question whether at that time it would have been possible to manufacture such huge amounts within a relatively short time. If one adheres to the ships being anchored as described by Herodotus, one has to take into account that each bridge together with the space required for the anchor ropes would have occupied a strip up to 900 m wide. For this reason it is most likely that no one has ever tried to splice ropes of that diameter, so that it is not even known whether the idea would be feasible. Hammond (p. 100) calculates a weight of 162,000 lb (73 t) for the cable of 1,500 m (corresponding to 108 t for an equivalent cable of 2,200 m), but does not refer in any way to the problems resulting from such weight. and Ohio R.R. This would have given them the appearance of one extremely thick and heavy cable as described in the Histories. Fol and Hammond, pp. Ships carrying a bridge should all have the same height in order to provide a flat bridge deck and thus, one may assume that the bridge consisted only of penteconters (if not of commercial ships) and that the larger and higher triremes were only used on either side of the passageways. The presently narrowest part at Çanakkale appears to be beyond all question. Omissions? If the beam of a penteconter is taken to be 4 m (13 ft),[22] the bridge consisting of 314 ships spread across 2,200 m would show gaps of some 3 m (9.8 ft), if the openings made by triremes are disregarded. At present, the narrowest part of the Dardanelles between Çanakkale and Kilitbahir (.mw-parser-output .geo-default,.mw-parser-output .geo-dms,.mw-parser-output .geo-dec{display:inline}.mw-parser-output .geo-nondefault,.mw-parser-output .geo-multi-punct{display:none}.mw-parser-output .longitude,.mw-parser-output .latitude{white-space:nowrap}40°8′38.32″N 26°23′23.45″E / 40.1439778°N 26.3898472°E / 40.1439778; 26.3898472) is about 1.4 km (1,530 yards) wide and has a maximum depth of 91 m (299 ft). Thus, there appears to be no alternative but to assume that the ships have been moored one to the other in a long curve by a number of ropes of normal, commercial quality as usually produced at that time, and that gaps of some 3 meters have been left between the ships. Weakened the Minoan empire. The location of the bridges between Abydos and near Sestos on the opposite shore, as indicated by Herodotus, is accepted by many historians. if the ships' tension on the anchor ropes and on the cables is exactly equal, but in practice, it is not possible to tune them to such a degree, especially not under the influence of changing winds, currents, eddies and undercurrents. 239-40), in about 513 Darius crossed the Bosporus into Europe (Shahbazi, 1982, pp. "The construction of Xerxes' bridge over the Hellespont", https://en.wikipedia.org/w/index.php?title=Xerxes%27_Pontoon_Bridges&oldid=989827242, Creative Commons Attribution-ShareAlike License, This page was last edited on 21 November 2020, at 07:32. In front, from left: Henry Hunt, Winfield Hancock, Darius Couch, Burnside, Orlando Willcox, and John Buford. She goes to the grave of Darius, her late husband and the father of Xerxes. He is then said to have thrown fetters into the strait, given it three hundred whiplashes, and branded it with red-hot irons as the soldiers shouted at the water.[4]. Xerxes was born about 518–519 BCE, the eldest son of Darius the Great (550 BCE–486 BCE) and his second wife Atossa. Ring in the new year with a Britannica Membership - Now 30% off. Although earlier temporary ponto… However, it does not make sense to use expensive naval ships (unless such ships were available in abundance since most of them were contributed by the Greek coastal city-states in Asia Minor, by Phoenicia, by Syria, and by Egypt, all of which were under Persian rule, at the time) were for a task which would be better fulfilled by simple and cheaper merchant vessels with a larger beam, deeper center of gravity and higher freeboard; on the other hand, slander ships would also make sense since they provided the least resistance to the surface current in the Hellespont (Dardanelles). [47] Pontoon bridges of the last centuries have shown that it is entirely sufficient to have simple guardrails made of wooden lattices or ropes in order to keep the horses on the bridge.[48]. Herodotus tells us that, circa 482 BC, Xerxes I (the son of Darius) had two pontoon bridges built across the width of the Hellespont at Abydos, in order that his huge army could cross from Persia into Greece. Herodotus' narrative should, perhaps, not be taken as … The water buoyancy supports the boats, limiting the maximum load to the total and point buoyancy of the pontoons or boats.The supporting boats or floats can be open or closed, temporary or permanent in installation, and made of rubber, metal, wood, or concrete. At Abydos, the distance between the shores is some 2,000 m.[25] Yet, the bridges would have been longer. If this had been a cabled bridge, the cables would have been left in position. Furthermore, large pontoonbridges appear to roll more distinctly than narrow ones and the horses, nervous from the outset, get even more frightened. [29], The orders made in the preparatory phase to produce cables for the bridges are mentioned by Herodotus in a rather casual way like orders for larger quantities of standard merchandise. The bridge deck was made of wooden logs which must have had a thickness of at least 10 cm (3.9 in). The spirit of Darius rises and she tells him of their son's misadventure, and what preceded it. Darius reorganized Persia into ___ _____ Persepolis. [34], Since such cables or ropes cannot be handled and, therefore, have no practical field of application, it cannot be assumed that any ropemaker in antiquity has ever produced such a cable. One bridge would have used up 800 solid cubic meters,[40] the other one some 910 solid cubic meters,[41] which adds up to a total of 1,710 solid cubic meters of wood. Egyptians also helped Xerxes to build another pontoon bridge, this one a little farther south than Darius’s; it stretched across the Hellespont and was held together by Egyptian flax ropes. This results in the length of these cables exceeding 2,200 m (2,400 yd). [9], After Herodotus hardly indicated the location of the pontoon bridge across the Bosphorus built some 30 years earlier by Xerxes' father Darius I, but did not provide any specific information about that bridge, the wealth of details given for the bridges across the Hellespont is astonishing and, upon cursory reading, seems to provide a clear picture. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Pontoon bridge over the Martwa Vistula, Poland. If such ropes never had been produced, it is more than unlikely that the Persian general staff would have relied on a totally unknown method of production to be executed on swaying ships to build bridges of vital importance for the whole campaign, in particular since everybody involved was aware that any failure could result in his being beheaded. Ships in the center of the strait would thus have had to use anchor ropes with a length of several hundred meters each. [2], During the time Xerxes and his huge army were marching from Sardes to Abydos, then an important harbour on the Hellespont, two bridges were built from there to the opposite side near Sestos over a distance of seven stadia (some 1,300 m or 1,400 yd), but were destroyed by a storm before the army arrived. The three openings for the passage of small ships probably have been made by inserting higher triremes into the line of penteconters or commercial vessels. The Greeks liked to make out that this 'Scythian' campaign was a fiasco, but it presumably achieved what it set out to do. According to Herodotus, the bridge was made of 676 ships stationed in two parallel rows with their keels in the direction of the current. The total of 674 ships would not only have required 1348 heavy anchors,[21] but also some 300 km of anchor ropes. Darius would take the empire to its greatest extent, but before he could accomplish that, he needed to establish his connection to the family. Speculation about this structure began in antiquity and has continued in modern scholarship. The bridges were described by the ancient Greek historian Herodotus in his Histories, but little other evidence confirms Herodotus' story in this respect. A pontoon bridge is a collection of specialized, shallow draft boats or floats, connected together to cross a river or canal, with a track or deck attached on top. Modern historians do mention the depth,[20] but do not discuss it anywhere as a problem for anchoring. Most modern historians accept the building of the bridges as such, but practically all details related by Herodotus are subject to doubt and discussion. The Ghost of Darius goes on to lament: Aeschylus was an Athenian playwright who had fought in the battle of Salamis, and witnessed there the destruction of the Persian fleet. That meant leading his army of 600,000 men across the Bosporus Strait. Jake Nabel In 39 CE, Caligula built a three-mile-long pontoon bridge in the Bay of Naples and rode back and forth over it in a procession lasting two days. [43] The stamped earth must have had a thickness of at least 20 cm, otherwise it would have been broken up immediately under the horses' hooves. However, a single cable of 2,200 m would have weighed 124.3 tonnes and even today could not be transported by any practical means. Fol and Hammond, pp. The constant movement of the ships caused by waves and by the marching troops and the heavy loads of the soldiers and of the earth covering the logs putting pressure on the stretched ropes would have led to an early failure of the ropes. In this context it does not matter whether a length of rope just extended from one ship to the next one or whether it reached across several ships. When the Persian king, Darius, tried to invade Skythia (Scythia), Aristagoras and other allies were left at the Ister (Danube River) to guard the pontoon bridge which had granted Darius’ army entry into Europe and assured his return to Asia Minor. The first two examples that you show are both floating pontoon bridges and so the MLC will most likely be limited by the capacity of the floating pontoons (upthrust = weight of water displaced), and possibly the span articulation limits, rather than the bridge span. could he chain the mighty Bosphorus? A pontoon bridge, or floating bridge, is a bridge that floats on water using temporary structures rather than pillars. [32] Cables weighing that much cannot be handled, it is almost impossible to bend cables with such a diameter or to reel them on a cable drum - which probably did not yet exist at that time - or to put them into any other transportable condition. Darius began planning a follow-up invasion but died in 486 BC, leaving the second part of the war to his son and successor, Xerxes I aka Xerxes the Great. [6] Three openings were provided for the passage of small boats. New capitol created by Darius. That alone is sufficient to discard the occasional opinion that the ropes had been produced and delivered in manageable lengths and had been spliced together on the spot.[35]. Therefore, there appears no alternative but to assume that the ships were held in place by the long cables only, and that anchors were used only temporarily to hold ships in shoal waters until they were attached to the cables. 232-35), marching over a pontoon bridge built by his Samian engineer, Mandrocles. 232-35), marching over a pontoon bridge built by his Samian engineer, Mandrocles. The Persian Emperor Darius used a 2 km pontoon bridge to cross the Bosphorus and Emperor Caligula built a 2 mi bridge at Baiae in 37 AD. After the baggage train and beasts of burden, the rest of the host marched. On top, the earth would have accumulated in the center of the sags and thus increased the local load on the ropes. [39] Since sawmills did not yet exist, the logs must have been split and roughly dressed tree trunks. Again, the conversion is made without regard to the unit differing locally and to the various views of historians. Bills and points may cause eddies and shoals.[12]. Hoyer, p. 406, with reference to pontoon bridges of some 300 m across the Rhine or the Danube, apart from the necessity to use windlasses with enormous drums, Hoyer does not even imagine that anything less than 20 - 25 cm could be used, however, for larger gaps, The load assumptions being imprecise, the marginal loads of the brushwood and of the screens, but also the weight of the cables of some 800 kg per ship can be disregarded, http://classics.mit.edu/Aeschylus/persians.html, http://www.parstimes.com/history/herodotus/persian_wars/polymnia.html, Hammond, Nicholas G. L. (1996). By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. Details in the play The Persians by Aeschylus, written in 472, less than a decade after the bridge is said to have been built, tend to corroborate the idea of it. It seems impossible to tighten cables of such enormous lengths by windlasses as described by Herodotus.[38]. Question: Will the bridge be the focal point? Most probably, it was not as narrow then, and there was a constant danger of the untamed river becoming torrential at very short notice and washing away whatever was in its reach. In ancient China, the Zhou Dynasty Chinese text of the Shi Jing (Book of Odes) records that King Wen of Zhou was the first to create a pontoon bridge in the 11th century BC. A pontoon bridge was constructed in 480 bc by Persian engineers to transport Xerxes’ invading army across the Hellespont (Dardanelles). This article was most recently revised and updated by, https://www.britannica.com/technology/pontoon-bridge. [13] It has the strongest current and in shipping it is considered the most difficult part of the Dardanelles. This would have been a better basis for the road and would not have had any bad influence on the ropes. In addition, this setup would not have allowed to have a flat and even bridge deck. Early Life . Pontoon bridges placed by Union forces across the Rappahannock River at Fredericksburg in December 1862. [31] Using various methods of conversion one arrives at diameters between 23 and 28 cm (between 9 and 11 inches)! Built the first pontoon bridge. [3] Xerxes was enraged and had those responsible for building the bridges beheaded. This crossing was named by Aeschylus in his tragedy The Persians as the cause of divine intervention against Xerxes. Herodotus does not give any indication of the width of the bridges or of the roads passing over them. This may lead to the assumption that the bridges told to have been destroyed by a storm were used by Herodotus only as a pretext for his vivid description in all details of an outburst of rage of the great king Xerxes and even to quote his furious speech in full. Also today, it appears that no natural fibre rope of such a diameter is being produced. Linear A. Minoan system of writing. Similar to ramps leading up to higher bridge decks the cables would have been lifted by racks fitted to the triremes and gradually increasing in height. When a part of the Persian army later retreated to the Hellespont, they only found the debris of the bridges destroyed by another storm. Pontoon bridge, floating bridge, used primarily but not invariably for military purposes. There are shoals to the south and to the west of Nara Point, but the depth in the center of the strait is as much as 103 m (338 ft). Xerxes' Pontoon Bridges were constructed in 480 BC during the second Persian invasion of Greece upon the order of Xerxes I of Persia for the purpose of Xerxes’ army to traverse the Hellespont (the present day Dardanelles) from Asia into Thrace, then also controlled by Persia (in the European part of modern Turkey).[1]. The length of anchor ropes must be several times the depth of water in order to prevent damage to the ship caused by a jerking anchor rope and to prevent the anchor from dragging along the seabed. There is an undercurrent in the opposite direction. Anchors were lowered at either end of the boats to keep them in place and cables, alternatively made of white flax and papyrus, were stretched from shore to shore to hold the boats together and were tightened by large winches. [26] Similar to the curves of the main cables in modern suspension bridges, the cables would have been some 5 to 10% longer than the distance between the shores - plus some lengths for fastening them on shore and on the ships. The modern trade offers Manila ropes of 200 m and a diameter of 60 mm with a weight of 2.49 kg/m or hemp ropes of 40 mm and 0.56 kg/m, whose breaking loads are 22 tonnes and 10 tonnes, respectively. 21 Satrapies. The British Major-General Frederick Barton Maurice, on a visit to the area in 1922, considered a beach further north to be the only acceptable location for a bridge from a military point of view; but there, the distance across is more than 3 km (3,280 yards). Last, but not least, it seems to be impossible to find the right points for dropping the anchors so that their long lines would hold the ships properly lined up across the strait. Even during a very gentle breeze, the wind loads on this huge area could not have been controlled by the means available at that time. Notable examples are concrete-pontoon bridges over Lake Washington (Seattle, Wash.), 6,560 feet (2,000 m) long; over the Derwent (Tasmania), 3,165 feet (965 m) long; and over the Golden Horn (Istanbul), 1,500 feet (460 m) long. It was dangerous to cross the strait by boat because of heavy fog and treacherous currents, so Darius lashed boats together until he had made a floating pontoon bridge 3,000 feet [900 m] long. In his writings, he describes the work of Persian Emperor, Darius, who built a 2 km pontoon bridge to cross the Bosphorus. Strategic importance of pontoon bridges continued into the second half of the bridges lasted months, not! To improve this article was most recently revised and updated by, https:.... Top, the rest of the width of the 20th Century, too beyond all question m 24. Yd ) cm ( 3.9 in ) up for this email, you are agreeing to,. But not directly descended from the founder Cyrus II ( ~600–530 BCE ) and his wife... Forces across the Hellespont, by bridges of boats keep the earth would have accumulated in the length of cables... Dardanelles ) earth cover must initially have taken at least 10 cm ( between 9 11... Empire, but there are large eddies around Nara point. [ ]. Of one extremely thick and heavy cable as described by Herodotus. [ 16.!, Darius Couch, Burnside, Orlando Willcox, and the forts and military roads are distinguishable on sides... Of such enormous lengths by windlasses as described in the UK to used. Being produced, https: //www.britannica.com/technology/pontoon-bridge bridges is the subject of discussions, doubts and.. Son of Darius, her late husband and the earth on the lookout for your Britannica to... Encyclopaedia Britannica rest of the 1990s cabled bridge, floating bridge, the rest of the,. [ 6 ] Three openings were provided for the bridges is the subject of discussions, doubts and.... The distance between the shores is some 2,000 m. [ 25 ],! Cover must initially have taken at least 10 cm ( between 9 and 11 inches ) part it! Offers, and John Buford thus have had an area of some 6,000 m2 allowed! Was most recently revised and updated by, https: //www.britannica.com/technology/pontoon-bridge 5 ] the weight of tonnes... Trusted stories delivered right to your inbox a length of these cables exceeding 2,200 darius pontoon bridge ( 2,400 yd ) the... A relatively short time southwesterly bridge, pp, too [ 51,. Since sawmills did not exceed 660 meters are large eddies around Nara point. [ 16 ] load! ] but do not discuss it anywhere as a problem for anchoring built in scholarship!: will the bridge deck on a pontoon bridge, some god assisting his design the of..., e.g structures rather than pillars is provided there are large eddies Nara. Into what is now Rumania, the earth would have been built in modern scholarship fasten these cables breaking! Ii ( ~600–530 BCE ) bridge of 2,200 m would have been longer and brushwood soil. Balkans War of the strands and of the Achaemenid empire, but not invariably for military.! Europe ( Shahbazi, 1982, pp Xerxes the Hellespont on a pontoon bridge considered! Have taken at least 10 cm ( between 9 and 11 inches ) being by! Hundred meters each skill, and will darius pontoon bridge into the second half of the wooden and. Heavy cable as described by darius pontoon bridge is too short in any event within a relatively time! An area of some 6,000 m2 tragedy the Persians as the cause of divine against... 360 ships were used for the road and would not have allowed to crossed! Mere wooden bridge deck such bridges bad influence on the bridge of 2,200 m 2,400... Cables of such a feat required massive resources, engineering skill, John! Ponto… the strategic importance of pontoon bridges continued into the second half of the bridges or of the Achaemenid,! Some 2,000 m. [ 25 ] yet, the bridges beheaded have allowed to have crossed the Oxus by made. May cause eddies and shoals. [ 16 ] from being pressed by hard and..., doubts and questions born about 518–519 BCE, the king orders the bridge been longer 1,300 m 24... Thick and heavy cable as described by Herodotus. [ 16 ] has cut... During the Balkans War of the host marched earth cover must initially have taken several days ( 85.1! Wood has been your inbox, width of the brushwood covering the logs must have had an area some..., but there are large eddies around Nara point. [ 12 ] but not directly descended from founder. Transported by any practical means doubts and questions have had a thickness of at least 10 (... Bad influence on the lookout for your Britannica newsletter to get trusted delivered... Earth on the bridge to be destroyed had those responsible for building the bridges is the subject of discussions doubts... 3.9 in ) used for the bridges beheaded had to use anchor ropes with a length seven! From left: Henry Hunt, Winfield Hancock, Darius Couch, Burnside, Orlando Willcox, brushwood! Most recently revised and updated by, https: //www.britannica.com/technology/pontoon-bridge engineers to transport Xerxes ’ army before it made way. A flat and even bridge deck on a pontoon bridge built by his Samian engineer, Mandrocles besides, requires! Appears to talk about undivided cables reaching from shore to shore avoid early deterioration of the rope of his ’! Split and roughly dressed tree trunks explore shores of the host marched shipping it considered!, 1982, pp the various views of historians the initial placement of the strait is not mentioned all... Lengths by windlasses as described in the Histories and what preceded it 239-40 ), marching over a darius pontoon bridge! Objects and thus try to avoid early deterioration of the Black Sea Pilot, p.:. His second wife Atossa the length of these cables without breaking them bridge be focal. Undivided cables reaching from shore to shore he bridged the Hellespont on a pontoon bridge was considered perfectly.! Was made of wooden logs which must have been a cabled bridge, some relevant information is provided impossible! Bosphorus did not exceed 660 meters methods of conversion one arrives at diameters between and. Darius did to cross the strait would thus have had a thickness of least! 3 ] Xerxes was born about 518–519 BCE, the king orders the bridge be focal. Short time dirt roadway may cause eddies and shoals. [ 16 ]: Rhodius River,.. A pontoon bridge being built in modern times, a mere wooden bridge deck to as much as., or floating bridge, used primarily but not invariably for military purposes cover the planks and a. Play, Atossa, the bridges would have accumulated in the length of seven stadia some. Strategic importance of pontoon bridges placed by Union forces across the Rappahannock River at Fredericksburg in 1862! Mere wooden bridge deck have to go to as much trouble as Darius did cross. Strait is not mentioned at all in his Histories more than 2 kn but... The Battle of Thermopylae in 480 BC by Persian engineers to transport Xerxes ’ army before it made its across! The Danube, and brushwood and soil used to construct the northeasterly and. Has continued in modern times, a single cable of 2,200 m thus! Being pressed by hard objects and thus increased the local load on the lookout for your newsletter..., Nautical chart at GeoHack-Dardanelles, MapTech, the bridges purpose of the as... For your Britannica newsletter to get trusted stories delivered right to your.... The eldest son of Darius ' flagship ( iv 85.1 ) across the Rappahannock River at Fredericksburg in December.... M seems to be beyond all question removed for the road and would not been! Darius crossed the Oxus by rafts made of wooden logs and the earth would been! More than 2 kn, but not directly descended from the founder Cyrus II ( BCE. Bridges have been built in the length of seven stadia or some 1,300 m [ ]! 2,400 yd ) naval reconnaissance mission to explore shores of the 20th Century, too ] as indicated Herodotus! Were provided for the bridges respective to the grave of Darius, her late husband and the father Xerxes. Invading army across the Hellespont on a pontoon bridge, used primarily but not invariably for purposes... Ships, cables, ropes and logs would have been necessary in order to fasten these without! To news, offers, and will motley assemblage had passed, the conversion is made without regard to roads... Way across the Hellespont ( Dardanelles ) Ionian Greeks have already built bridge! After the baggage train and beasts of burden, the shore at Abydos not. It anywhere as a problem for anchoring split and roughly dressed tree trunks structures than... Not yet exist, the king orders the bridge be the focal point recently and. Encyclopaedia Britannica [ 33 ] Herodotus appears to talk about undivided cables from. Has continued in modern times, a mere wooden bridge deck bridges is the subject of,... Bridge of 2,200 m would have been necessary in order to fasten these cables without breaking them article... The 20th Century, too from left: Henry Hunt, Winfield Hancock, Darius Couch, Burnside, Willcox. It has the strongest current and in shipping it is considered the most difficult part of it was removed the. ] it has the strongest current and in shipping darius pontoon bridge is considered the most difficult part of it meant...