Roman and Gothic Atlantic fleets

Haesten

Ad Honorem
Dec 2011
2,918
#11
Tacitus - Agricola 28.

"The same summer a Usipian cohort, which had been levied in Germany and transported into Britain, ventured on a great and memorable exploit. Having killed a centurion and some soldiers, who, to impart military discipline, had been incorporated with their ranks and were employed at once to instruct and command them, they embarked on board three swift galleys [liburnicas] with pilots pressed into their service. Under the direction of one of them—for two of the three they suspected and consequently put to death—they sailed past the coast in the strangest way before any rumour about them was in circulation. After a while, dispersing in search of water and provisions, they encountered many of the Britons, who sought to defend their property. Often victorious though now and then beaten, they were at last reduced to such an extremity of want as to be compelled to eat, at first, the feeblest of their number, and then victims selected by lot. Having sailed round Britain and lost their vessels from not knowing how to manage them, they were looked upon as pirates and were intercepted, first by the Suevi and then by the Frisii. Some who were sold as slaves in the way of trade, and were brought through the process of barter as far as our side of the Rhine, gained notoriety by the disclosure of this extraordinary adventure."

Liburna - Wikipedia

The Liburna were in the Irish Sea and sailed around Scotland.
 
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Chlodio

Forum Staff
Aug 2016
4,074
Dispargum
#13
A large sailing ship is faster than a small sailing ship, distance between the bow wave and stern wave created when a displacement mono hull moves through water.
This is based on several assumptions: that everything else between the big ship and the small ship are equal, also that the big ship and the small ship are both capable of reaching their theoretical maximum speeds. The big ship, being heavier, requires more energy to propel it forward. This energy comes either from the muscle of the oarsmen or from the wind via the sails. Given the limits of human strength and the inefficiency of ancient sails, I doubt any ancient ships achieved their theoretical maximum hull speeds. For instance, the theoretical max hull speed of a 121' trireme is almost 15 knots, but no source I've read claims that kind of speed for a trireme - closer to 7-10 knots in the sources.
 

Haesten

Ad Honorem
Dec 2011
2,918
#14
This is based on several assumptions: that everything else between the big ship and the small ship are equal, also that the big ship and the small ship are both capable of reaching their theoretical maximum speeds. The big ship, being heavier, requires more energy to propel it forward. This energy comes either from the muscle of the oarsmen or from the wind via the sails. Given the limits of human strength and the inefficiency of ancient sails, I doubt any ancient ships achieved their theoretical maximum hull speeds. For instance, the theoretical max hull speed of a 121' trireme is almost 15 knots, but no source I've read claims that kind of speed for a trireme - closer to 7-10 knots in the sources.
Power (sail area) to weight ratio obviously, a scaled up version of a warship has a scaled up sail area. Basically the bow wave moves towards the stern and the stern wave moves towards the bow as the ship increases speed, when they meet roughly amidships that's as fast the hull can go without picking up on the plane.
 

Chlodio

Forum Staff
Aug 2016
4,074
Dispargum
#15
Power (sail area) to weight ratio obviously, a scaled up version of a warship has a scaled up sail area.
I understand your theory of maximum hull speed. I'm saying it doesn't translate into maximum practical speed. The comparisons between big Roman triremes and smaller barbarian long ships is neither linear nor proportional. Triremes usually had ballistae and similar catapult-type weapons. The weight of these weapons would slow down the triremes. Barbarian ships had no catapults so the ships were lighter and gained an efficiency for speed. Triremes were built sturdier for ramming. The thicker hulls added weight and reduced speed. Barbarian ships generally did not ram. They were built lighter and faster. Triremes carried separate oarsmen and marines. On barbarian ships the oarsmen and marines were the same men - no extra weight for extra crewmen. Then we get into differences in construction. Roman triremes were carvel-built. Barbarian ships were clinker-built. Clinker ships were more hydrodynamic as they displaced less water - clinker ships could go faster on the same propulsion energy because they had to push less water out of the way.

Only modern racing yachts come close to achieving maximum hull speed. Ancient warships were built for other things besides speed (weapons, sturdiness, marines, etc). These other factors reduced the maximum practical speed, but these other factors were not constant from one ship-type to another.

I started out saying big ships vs small ships. We should not understand this in terms of length. We should understand big and little in terms of weight or more specifically, displacement. Ships that displace more water are generally slower than ships that displace less water.
 
Last edited:
Mar 2015
1,427
Yorkshire
#16
OK, Atlantic is quite different from Mediterranean, being stormy and difficult. So, what I am interested is, how did Romans adapt to Atlantic conditions once they reached Atlantic shores? And what about Gothic (Visigothic) kingdom after that? From what I have managed to find, a Roman actually commanded Visigothic fleet:
History of the Goths
The Roman Empire and Its Germanic Peoples

However, I had found no information on organization or types of ships so far.
The information concerning the Gallo-Roman "admiral" Namatius of Saintes comes from Sidonius, a Gallo-Roman noble and bishop of Clermont, central France, in eulogy composed in late 470AD.

"recently you sounded the bugle in the fleet and performing the duties first of sailor and then a soldier" you wandered about the sinous shores of the ocean in opposition to the serpentine pirate ships of the Saxon... you accompanied the standards of the victorious people (ie the Visigoths of Aquitaine)"

Although Namatius' title is not given, he seems to be performing the role very similar to the Count of the Saxon Shore or dux tractus armoricini, Duke of the Armorican Region.

I would expect that he operated a similar fleet to that of the Classis Brittanicus or Classis Germanicus.

Although they had used them in the First Century, the Romans , soon dispensed with the huge triemes and biremes of the wars with Carthage. Even in the Mediterranean these vessels had proven too unweldly and too expensive against nibble pirate ships. Typically, the Romans simply copied the pirates, adding the Liburnian ship (named after these Coatian tribe) to their fleet, with the addition of ram (seems it was not a fighting vessel in Roman eyes if it did not have a ram). These were extensively used in the 2nd Century to combat the Chauci (forerunners and I believe one and the same as the Saxons of a Century later).

The Liburnian had a crew of 50 rowers in a single row (although larger double tiered versions were made). It was still a complicated ship and very expensive to manufacture. liburnian.JPG

and in Trajan's war


liburnian 2.JPG

The Lusoria, a fast light scouting warship is often mentioned in Late Roman sources but unfortunately we do not have a description in detail. Vegetius, early 5th Century does talk about the scafa exploratoria, fast 20 oared ship used for scouting and interception.

Finally there is the Mainz A boat. Although this has only been found in a riverine environment on the Rhine it is believed to be very seaworthy, has a higher freeboard with an apparent provision for hanging shields (Viking style), very manoeuvrable, half the crew and costing a fraction of the price of a Liburnian to build since it owes it technology to the Celtic shipbuilding techniques (BTW the Celts were the shipbuilders par excellence).

Mainz A.JPG


Reconstruction of Mainz A warship (possibly modified for the North Sea) - note the excluse of a Ram - very Roman!
 
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authun

Ad Honorem
Aug 2011
5,219
#17
This is a sculpture of a roman wine ship in Trier.




And this is a reconstruction of it:




Although it was a river ship, one could make short journey's on the sea, afterall people do row the atlantic even today. One had to pick the weather, as in 1066 when William had to delay. There were no all purpose all weather ships. The Gallic Veneti were noted for their ships an seamanship too. Julius Caesar writing in the 1st century BC:

"These Veneti exercise by far the most extensive authority over all the sea‑coast in those districts, for they have numerous ships, in which it is their custom to sail to Britain, and they excel the rest in the theory and practice of navigation. As the sea is very boisterous, and open, with but a few harbours here and p149 there which they hold themselves, they have as tributaries almost all those whose custom is to sail that sea." (gallic wars III)
 

authun

Ad Honorem
Aug 2011
5,219
#19
It appears to ride high in the water. Presumably when loaded down with wine casks it would ride lower. Was it in any way unstable due to being top heavy? Is that why it could only sail in calm weather?
I don't know how the hull is designed but yes, when loaded with wine, low down, it would be lower in the water. Roman ships brought basalt quernstones to Britain from the Vulkaneifel region. They were picking up lead and grain in Britain but needed heavy balast for the journey to britain. I've no idea how they handled though,
 

Frank81

Ad Honorem
Feb 2010
5,050
Canary Islands-Spain
#20
OK, Atlantic is quite different from Mediterranean, being stormy and difficult. So, what I am interested is, how did Romans adapt to Atlantic conditions once they reached Atlantic shores?

One well known event of the Romans facing Atlantic enemies was that of Julius Caesar in Armorica, modern Brittany. The Gauls had round sailing ships, and fortified islands and bases along the shoreline, one though scenario. Let me do a selection:

https://www.stcharlesprep.org/01_parents/oneil_j/Useful Links/AP Latin Assignments/HW/The Gallic Wars.pdf

Book 3:

The occasion of that war was this: P. Crassus, a young man, had taken up his winter quarters with the seventh legion among the Andes, who border upon the [Atlantic] ocean. He, as there was a scarcity of corn in those parts, sent out some officers of cavalry, and several military tribunes among the neighbouring states, for the purpose of procuring corn and provision; in which number T. Terrasidius was sent among the Esubii; M. Trebius Gallus among the Curiosolitae; Q. Velanius, T. Silius, amongst the Veneti.

Chapter 8
The influence of this state is by far the most considerable of any of the countries on the whole sea coast, because the Veneti both have a very great number of ships, with which they have been accustomed to sail to Britain, and [thus] excel the rest in their knowledge and experience of nautical affairs; and as only a few ports lie scattered along that stormy and open sea, of which they are in possession, they hold as tributaries almost all those who are accustomed to traffic in that sea.

...

Chapter 9
Caesar, being informed of these things by Crassus, since he was so far distant himself, orders ships of war to be built in the mean time on the river Loire, which flows into the ocean; rowers to be raised from the province; sailors and pilots to be provided. These matters being quickly executed, he himself, as soon as the season of the year permits, hastens to the army.

The Veneti, and the other states also, being informed of Caesarʹs arrival, when they reflected how great a crime they had committed, in that, the embassadors (a character which had among all nations ever been sacred and inviolable) had by them been detained and thrown into prison, resolve to prepare for a war in proportion to the greatness of their danger, and especially to provide those things which appertain to the service of a navy, with the greater confidence, inasmuch as they greatly relied on the nature of their situation. They knew that the passes by land were cut off by estuaries, that the approach by sea was most difficult, by reason of our ignorance of the localities, [and] the small number of the harbors, and they trusted that our army would not be able to stay very long among them, on account of the insufficiency of corn; and again, even if all these things should turn out contrary to their expectation, yet they were very powerful in their navy.

They well understood that the Romans neither had any number of ships, nor were acquainted with the shallows, the harbors, or the islands of those parts where they would have to carry on the war; and the navigation was very different in a narrow sea from what it was in the vast and open ocean. Having come to this resolution, they fortify their towns, convey corn into them from the country parts, bring together as many ships as possible to Venetia, where it appeared Caesar would at first carry on the war. They unite to themselves as allies for that war, the Osismii, the Lexovii, the Nannetes, the Ambiliati, the Morini, the Diablintes, and the Menapii; and send for auxiliaries from Britain, which is situated over against those regions.

...

Chapter 12
The sites of their towns were generally such that, being placed on extreme points [of land] and on promontories, they neither had an approach by land when the tide had rushed in from the main ocean, which always happens twice in the space of twelve hours; nor by ships, because, upon the tide ebbing again, the ships were likely to be dashed upon the shoals.

Thus, by either circumstance, was the storming of their towns rendered difficult; and if at any time perchance the Veneti overpowered by the greatness of our works, (the sea having been excluded by a mound and large dams, and the latter being made almost equal in height to the walls of the town) had begun to despair of their fortunes; bringing up a large number of ships, of which they had a very great quantity, they carried off all their property and betook themselves to the nearest towns; there they again defended themselves by the same advantages of situation. They did this the more easily during a great part of the summer, because our ships were kept back by storms, and the difficulty of sailing was very great in that vast and open sea, with its strong tides and its harbors far apart and exceedingly few in number.

Chapter 13
For their ships were built and equipped after this manner:

The keels were somewhat flatter than those of our ships, whereby they could more easily encounter the shallows and the ebbing of the tide: the prows were raised very high, and, in like manner the sterns were adapted to the force of the waves and storms [which they were formed to sustain]. The ships were built wholly of oak, and designed to endure any force and violence whatever; the benches which were made of planks a foot in breadth, were fastened by iron spikes of the thickness of a manʹs thumb; the anchors were secured fast by iron chains instead of cables, and for sails they used skins and thin dressed leather.

These [were used] either through their want of canvas and their ignorance of its application, or for this reason, which is more probable, that they thought that such storms of the ocean, and such violent gales of wind could not be resisted by sails, nor ships of such great burden be conveniently enough managed by them.

The encounter of our fleet with these shipsʹ was of such a nature that our fleet excelled in speed alone, and the plying of the oars; other things, considering the nature of the place [and] the violence of the storms, were more suitable and better adapted on their side; for neither could our ships injure theirs with their beaks (so great was their strength), nor on account of their height was a weapon easily cast up to them; and for the same reason they were less readily locked in by rocks. To this was added, that whenever a storm began to rage and they ran before the wind, they both could weather the storm more easily and heave to securely in the shallows, and when left by the tide feared nothing from rocks and shelves: the risk of all which things was much to be dreaded by our ships.

Chapter 14
Caesar, after taking many of their towns, perceiving that so much labor was spent in vain and that the flight of the enemy could not be prevented on the capture of their towns, and that injury could not be done them, he determined to wait for his fleet. As soon as it came up and was first seen by the enemy, about 220 of their ships, fully equipped and appointed with every kind of [naval] implement, sailed forth from the harbor, and drew up opposite to ours; nor did it appear clear to Brutus, who commanded the fleet, or to the tribunes of the soldiers and the centurions, to whom the several ships were assigned, what to do, or what system of tactics to adopt; for they knew that damage could not be done by their beaks; and that, although turrets were built [on their decks], yet the height of the stems of the barbarian ships exceeded these; so that weapons could not be cast up from [our] lower position with sufficient effect, and those cast by the Gauls fell the more forcibly upon us.

One thing provided by our men was of great service, sharp hooks inserted into and fastened upon poles, of a form not unlike the hooks used in attacking town walls. When the ropes which fastened the sail‐yards to the masts were caught by them and pulled, and our vessel vigorously impelled with the oars, they [the ropes] were severed; and when they were cut away, the yards necessarily fell down; so that as all the hope of the Gallic vessels depended on their sails and rigging, upon these being cut away, the entire management of the ships was taken from them at the same time.

The rest of the contest depended on courage; in which our men decidedly had the advantage; and the more so, because the whole action was carried on in the sight of Caesar and the entire army; so that no act, a little more valiant than ordinary, could pass unobserved, for all the hills and higher grounds, from which there was a near prospect of the sea were occupied by our army.

Chapter 15
The sail yards [of the enemy], as we have said, being brought down, although two and [in some cases] three ships [of theirs] surrounded each one [of ours], the soldiers strove with the greatest energy to board the ships of the enemy; and, after the barbarians observed this taking place, as a great many of their ships were beaten, and as no relief for that evil could be discovered, they hastened to seek safety in flight.

And, having now turned their vessels to that quarter in which the wind blew, so great a calm and lull suddenly arose, that they could not move out of their place, which circumstance, truly, was exceedingly opportune for finishing the business; for our men gave chase and took them one by one, so that very few out of all the number, [and those] by the intervention of night, arrived at the land, after the battle had lasted almost from the fourth hour till sun‐set.
 

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