The most comprehensive visual evidence about Roman army of I-II centuries is the Trajan column. It shows in great detail cloths, weapons, ships, military machines and other equipment of the Roman army. Here is an enigmatic depiction from this column:

The image is taken from this web site:

enter image description here

It seems from context that this is some siege equipment. What could this possibly be?


5 Answers 5


This actually came up in discussion when I was studying the archaeology of Roman Britain.

In fact, as far as I'm aware, nobody knows for certain, but several archaeologists that I have spoken to suggested that they were meant to be three-wheeled plutei, which were screens intended to protect the attacking force besieging a city.

The objects can be seen here in context against the walls of the city:

Section of Trajan's column

Plutei and other forms of protective shield are described in Vegetius' Epitome of Military Science (pp128-129). In fact, in the linked edition, in the footnotes on page 129 the editor, N.P Milner, notes that:

The triangular chassis with three wheels which are illustrated on Trajan's column, Cichorius Pl. LXXXV scene cxiv, may be intended to represent plutei.

It is worth noting that the archaeologist Ian Richmond, then at the British School at Rome, was of a different opinion. He did not consider that the objects were part of the Roman siege equipment at all.

In his paper Trajan's Army on Trajan's Column, published in Papers of the British School at Rome Vol. 13 (1935), pp. 1-40, he discusses the features of the objects and concludes that it more likely that the objects represented festucae, or 'pounders' used in the construction of the Murus Gallicus, and as such, would have been used by the Dacian defenders, rather than the Romans attacking the city of Sarmisegetusa.

Such devices are mentioned by Vitruvius in Book 3 of his De architectura where he describes the construction of temple foundations:

"Intervalla autem concamaranda aut solidanda festucationibus, uti distineantur"


"The spaces between the columns are to be arched over, or made solid by being rammed down, so that the columns may be held apart."

Professor Richmond went on to argue that:

"... their presence here will indicate that this part of the fortification was newly completed, shortly before the arrival of the Romans."

This interpretation has the advantage that it does at least explain all the visible features of the objects but, as I said earlier, it is not possible to be certain.

  • I agree it was most likely a device used by the defenders. I'm not sure where this battle is taking place, but It looks like an ancient crop sprayer using barrels to hold water. Oct 14, 2018 at 5:14

It seems to be not entirely clear. But it also seems to represent an unusual depiction of an otherwise well known instrument:

Scene of a siege from Trajan's Column (Rome). The defenders roll barrels and tree trunks downhill (top right), but these are intercepted by three peculiar machines. The German scholar Otto Lendle made the astute observation that these are likely, to represent Apollodorus' 'ship's prow tortoises'. (C. Cichorius, Die Reliefs der Traianssaule, Berlin 1900).
Duncan B Campbell: "Besieged. Siege Warfare in the Ancient World", Osprey: Oxford, New York, 2006, p197.

Another view of the relevant picture:

enter image description here File:085 Conrad Cichorius, Die Reliefs der Traianssäule, Tafel LXXXV (Ausschnitt 01).jpg

In the original called the Schiffsbugschildkröten of Apollodorus. If true then it would be one of his Poliorketika, another form of testudo or (chelone).

This work of Apollodorus seems to be this one:

enter image description here or earlier: enter image description here enter image description here

Source for last two pictures: British Library, Burney MS 69, ff 33v-52r

Apollodorus of Damascus, Poliorcetica (TLG 1165.001), imperfect, lacking the final paragraph (193.1). Twenty-eight coloured drawings. Tit. ᾽Εκ τῶν ᾽Απολλοδώρου πολιορκητικὰ.

Personally, I'd been lead to believe this looks most likely like a crossbreed between an early trebuchet and some kind a wrecking ball, although both are not recognised at such an early date.

The explanatory text given on the site where the picture in the question was found says:

TRAJAN'S COLUMN LXXXV/CXIV (Scene 114): War Machines
Scene 114/CXIV: Close view of odd machines that have been interpreted variously as serving offensive or defensive purposes: "anxious to show these things to the best advantage, the Maestro has raised the line of the wall almost to the top of the scroll, leaving him just enough room to display their component parts, but no room to show how they were operated and by which side" (Lepper/Free 1988: 165).
From cast 308, now in the Museo della Civiltà Romana, Rome. Compare Cichorius Pl. LXXXV, scene 114 and Coarelli Pl. 140. Ref: RBU2011.8203

Source trajan's Column.org Quoting: Lepper, F. and S. Frere. 1988, (rev.) 2015. Trajan ‘s Column : A New Edition of the Cichorius Plates. Gloucester, UK and Wolfeboro, NH. Revised edition 2015: Fonthill media.

But the more widespread conjecture is that:

The curious wheeled machine in scene CIV is stylistically very similar to a surviving drawing from Apollodorus' Poliorcetica and may represent another direct input from this architect, *albeit one misunderstood by the sculptor.[…]
The strange device depicted in front of the polygonal masonry wall in scene CXIV has attracted a great deal of scholarly speculation, non of which has solveed the problem of its function. It corresponds with no known form of ancient artillery, wall-batterer, pile-driver or defensive engine. Detached examination reveals no logical explanation of its working parts. Its main compositional role on the frieze seems to have been to fill the empty space above the group of Roman soldiers in the scene and the sculptor himself evidently did not have much idea of what he was depicting. The triangular frameworks of beams with associated circular objects are most reminiscent of the tread-mill cranes which would have been visible around the forum-basilica building site, but this observation only makes the device's obscurity more surprising, given that such cranes were intelligibly depicted elsewhere in Roman sculpture. A surviving manuscript illustration from Apollodorus of Damascus's Poliorcetica pictures a siege tower on little wheels like those in scene CXIV, and employs the same overall perspective style. This again suggests Apollodorus' direct involvement with the frieze and further reveals architect's general knowledge of military engineering. It does not, however, provide enlightenment as to the function of the device in scene CXIV.

J. C. Coulston: "Trajan's Column: The Sculpting and Relief Content of a Roman Propaganda Monument", Thesis, Newcastle University Library: Newcastle upon Tyne, 1988, p 161–162. (PDF)


Perhaps the carved relief depicts some sort of land weapon. Three three wheeled triangular wood framed devices are linked with a series of barrels at the third top wheels forming a rolling linked wall perhaps? I observe that on each of the wheels to the left of the triangular frames have a hook which I guess might be a scythe like blade, which when the whole contraption is released or pulled via horses at either end of the barrel chain down a hill barrel end and single wheels first pull the scythe chariots along with it in a near unstoppable wall of terror at an opposing enemy line. Just a guess with nothing much to base my guesswork on other than the scythe hook like blades on each of the left hand wheels. I recall in the film Spartacus the gladiator army rolled flaming barrels or logs down a hill initially pulled with ropes either end to build momentum. It may well be the Dacian rather than Roman weapon. Then again I could be completely wrong.not helped that I think the artisan had difficulty in its depiction in 3D form. I’d be interested with others thoughts.

  • 3
    Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.
    – Community Bot
    Oct 15 at 22:56

OR... It could simply be something unrelated to war or siege. As I drove down the Kansas back roads, I saw this today.

Irrigation System

So, what if the barrels are storage for water for irrigation because they didn't have well pumps like we do today? When you consider it, the Romans had aqueducts and plumbing, so why not advanced irrigation systems like we have today, only gravity fed? Or perhaps aqueduct fed with the barrels for extra water when the aqueduct ran a little slow?

  • The barrel shapes are similar to how ancient mallets were made. The hook could be to hold the machine in place while it moved back and forth pounding. Unfortunately this is the only image of such of thing and it's probable that the artist had to rely on sketches drawn by others or worse, a description. Oct 17 at 8:01

Water pipe, jointed at intervals for flexibility. The column concentrates on logistics. Nothing is more important to a soldier than potable water.

Just a guess. It looks too weak, yet complicated, structurally to be even an effective barrier, let alone an offensive engine. The joints look like leather capped with wood or bronze. Looking at the detail of the supports, perhaps they're a poor depiction of tripods, with two wheels and an unwheeled hinged pole. But I have no idea about the 'scythes' on the far side of the far wheels. Or are they flowing water, the sculptor depicting his understanding of taps at intervals??

  • 3
    Is that an educated guess or do you have some supporting evidence for this suggestion?
    – Steve Bird
    Oct 15 at 11:50
  • Just a guess. It looks too weak, yet complicated, structurally to be even an effective barrier, let alone an offensive engine. The joints look like leather capped with wood or bronze. Looking at the detail of the supports, perhaps they're a poor depiction of tripods, with two wheels and an unwheeled hinged pole. But I have no idea about the 'scythes' on the far side of the far wheels. Or are they flowing water, the sculptor depicting his understanding of taps at intervals?? ...Steve G. Oct 15 at 12:12

Not the answer you're looking for? Browse other questions tagged or ask your own question.