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Giant Ships of Rome
#1
I was asked in another thread to open discussion about Roman "giant ships", such as vessels excavated from lake Nemi and now dated to AD 31-41 according to numismatic evidence.

These two enormous ships - a sailing ship and an oared galley - were built and anchored on lake Nemi. Remains of a temple was recovered from the second ship; they are now believed to have been connected with Isis worship. Lake Nemi was sacred to Diana (Diana Nemorensis), but from the time of Caligula there was also a prominent shrine of Isis.

Pillaged and deliberately sunk later in the first century (possible after Nero's fall?), they were recovered in a feat of engineering sponsored by Benito Mussolini in the 1930s, but destroyed during the second world war in 1944.

In 1999 Rosario D'Agata, former public relations director of an Italian petroleum company, established the Association Dianae Lacus to replicate Caligula's huge sailing ship - however, there has been significant delays. Reconstructed keel is now preserved in the empty museum built for these two ships.

Nemi ships were in my opinion one of the most important finds in terms of Roman maritime archeology. They were evidently built to highest standard and they did reveal several interesting and surprisingly advanced technical details:

- So-called "admiralty type anchors", first adopted in 1836-1852 in the British Navy
- Copper nails made of almost pure electrolytic copper. I would very much like to hear from a person acquainted with metallurgy, how this was achieved.
- Ball bearings. Possibly originating from a rotating platform?
- Piped water.

Another of Caligula's giant ships (a "mirabilis navis"), an obelisk carrier from Alexandria was deliberately sunk and filled with hydraulic cement in Ostia, as Suetonius tells us:
Quote:He formed the harbour at Ostia, by carrying out circular piers on the right and on the left, with a mole protecting, in deep water, the entrance of the port. To secure the foundation of this mole, he sunk the vessel in which the great obelisk had been brought from Egypt; and built upon piles a very lofty tower, in imitation of the Pharos at Alexandria, on which lights were burnt to direct mariners in the night. (Claud. 20.3)

The mole was excavated by O. Testaguzza, who did find remains of five ships, one of which was identified as the gigantic obelisk carrier (though estimates of its size vary).

To compare these behemoths of antiquity to later sailing ships, I made following table and diagram:

[Image: ship_comparison_small.gif]

[Image: ship_comparison2_small.gif]
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#2
:o o o o
MNI Gioi u F**ckers Smile <img src="{SMILIES_PATH}/icon_smile.gif" alt="Smile" title="Smile" />Smile
Remarks by Philip on the Athenian Leaders:
Philip said that the Athenians were like the bust of Hermes: all mouth and dick.
:lol: <img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" />:lol:
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#3
Very interesting article! Confusedhock:
But there are quite reasonable doubts if Nemi ships ever existed and obelisk ship too, there are too many unanswered questions. Some people even believe that Nemi ships were fascits' forgery.


Here are some questions:
-propelling such a big ships by oars deemed impossible
-too big sails (doubtful to handle) how many men would be needed to hoist yard with sail? (both on obelisk carrier and Nemi ships) if we consider that some 30 men needed to hoist the frigate President topsailyard
-lake Nemi is very small (1.67 square km) such ships were probably not expected to sail (lake is surrounded by hills) but build solely sacred to deity?
-areas of rudders are very small, presumably insufficient to steer the vessel
-strange damage of ships at the end of the WW II.

and many more questions to be answered...
Anyway it would be interesting to hear from other people their opinions etc. :o
Martin
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#4
Quote:But there are quite reasonable doubts if Nemi ships ever existed and obelisk ship too, there are too many unaswered questions. Some people even believe that Nemi ships were fascits' forgery.

Some people even believe that the moon landing was a forgery. Smile

I know the importance of playing the Devils' Advocate, but consider that the history of the Nemi ships, including the whole process of empyting the lake and preservation of the wrecks, has been extensively documented. Statuary finds are displayed in museums. I find it hard to stomach such incredulousness in front of such evidence.

The obelisk carriers are a harder case. Back in the 1800s many refused to believe that romans could have built such a ship and many continued to think so until the Nemi ships were unearthed. Recently a new and quite original theory about the obelisk carriers have been proposed by A. Wirsching in "Die Obelisken auf dem Seeweg nach Rom" (2002) RM 109, 141-156. Abstract:
"The erection of two obelisks at Rome before 10 B.C. must be considered in connection with the erection of two obelisks at Alexandria 13-12 B.C. The comparison of all activities around these events indicates, that a close co-operation of Romans and Egyptians took place from 15 B.C. onward. Before the first obelisk transport to Rome, Roman engineers and shipbuilders had the opportunity to study the Egyptian transport technology on the Nile. Based on these experiences, the Roman navy was capable of constructing an appropriate ship for the transport of obelisks across the Mediterranean. Until now it was believed, that heavy, granite objects were laid on top of ships at the stone quarries near Aswan and then brought northward. This assumption can no longer be upheld. Instead columns and obelisks were transported hanging in water between the two hulls of a double-ship. The loading of a double-ship was easy and without using any power. The Roman obelisk-ship was composed of three interconnected ships. Two ships supported the obelisk, which hung between them in the water, and the third ship was centred between their bows. The ship in front provided the streamlined water flow necessary at open sea, and also the propulsion. Of all Roman ship types the trireme appears best suited to be adapted to this role as an integral part of the obelisk-ship. As the result of this investigation every detail contained in reports of Pliny, Suetonius and Ammianus corresponds to the construction of the hypothetical Roman obelisk-ship. Definite clues about the Roman double-ship technology give remarks on the sinking of Caligula's obelisk-ship in the Portus near Ostia. A part of the former western mole, which consists of pozzolana concrete has to be interpreted as a platform built up on pillars above the obelisk-ship."


Quote:Here are some questions:
-propelling such a big ships by oars deemed impossible
-too big sails (doubtful to handle) how many men would be needed to hoist yard with sail? (both on obelisk carrier and Nemi ships) if we consider that some 30 men needed to hoist the frigate President topsailyard
-lake Nemis is very small (1.67 square km) such ships were probably not expected to sail (lake is surrounded by hills) but build solely sacred to deity?
-areas of rudders are very small, presumably insufficient to steer the vessel
-strange damage of ships at the end of the WW II.

- Question about the sail size is adequate. I'm no nautical expert myself, but I reckon it was discussed in length in Lionel Casson's Ships and Seamanship. To the best of my knowledge, there is no physical reason why these ships could not be propelled.

- Lake Nemi ships were not intended to be moved. Actually, they weren't built to be seaworthy. In my view they were nearly stationary pieces of religious architecture. They make perfect sense in connection with the mysteries of Isis, where ships played an important part.

- As far as I know, nobody knows exactly how the Nemi ships were burned and why. Museum staff found the site all burned down after german artillery had retreated from the hills (which were under allied artillery barrage) and it was occupied by american troops. A museum official who inspected the site during the battle later told that german artillery tractors had caused damage to the museum yard and a few colums were knocked down, but the ships were still intact. Nazis were blamed for the act of course, but I've failed to found any concrete evidence in this case. It is perfectly possible that some disgruntled artilleryman had torched the ships for some horrendously stupid reason, but: We don't know. Maybe it counts as a mystery.
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#5
Solution proposed by A. Wirsching in Die Obelisken auf dem Seeweg nach Rom sounds much more realistic. Transportaion of heavy blocks submerged and supported by floats (using their volumetric displacement) is well known already. Such a way of transportation of heavy blocks was also practically proved by Pavel Pavel, a Czech engineer, who was interested in ancient mechanics. (By the way his method of moving moiai on the Easter Island was heartily accepted by Thor Heyerdahl. They both tested walking moiai on the island with great success).

Obelisk ship:
- there is big difference between 55m grain carrier primarly propelled by sails and 104m so called obelisk ship
- such a big ship would suffer from hogging - serious problem even in smaller ships, hulls of big clippers like Great Republic or multi-mast schooners such as Wyoming were heavily strengthened with iron
- ship sail is too huge, heavy and cumbersome, considering difficulties with huge topsails of big clippers, it would be more probable to have more masts and sails on obelisk ship
- enormous single mast is rather out of question, to find single tree big enough seems to be impossible, the biggest wooden sailing ships (smaller then obelisk ship) had masts from several pieces
- transportation of obelisk between two hulls, taking advantage of it's volumetric displacement is ingenious and that’s quite different story from your first post
- steering such a floating object with small oars (insufficient steering oars areas) would be very difficult if not impossible (there is relation between submerged hull and steering rudder areas)

Quote:The ship in front provided the streamlined water flow necessary at open sea, and also the propulsion.

This idea seems a little cumbersome since such joined three hulls as described would be far from being streamlined, not talking about manoeuvreability, but towing of a raft with obelisk by smaller oar/sail propelled ships is quite possible.

Nemi ships:
Just to clear my view - I'm not trying to say that these ships never existed, I'm trying to say that there are many mysteries and strange things.
- enormous quantity of wood needed to built ships, transportation of wood to the hills (suppose there were no forests around)
- how Isis or Diana are connected with ships/water?
- why two ships?
- even for naumachia the size of ships is not understandable
etc.
Martin
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#6
This is the same scale as trading vessels on the Indian Ocean. The ships took advantage of the monsoon winds and took them out to India, stayed for nine months then returned in the opposite season when the winds blew the same way. Now if you are staying in country for nine months you need a very large cargo space.
Theodoros of Smyrna (Byzantine name)
aka Travis Lee Clark (21st C. American name)

Moderator, RAT

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#7
Quote:Instead columns and obelisks were transported hanging in water between the two hulls of a double-ship. The loading of a double-ship was easy and without using any power. The Roman obelisk-ship was composed of three interconnected ships. Two ships supported the obelisk, which hung between them in the water, and the third ship was centred between their bows. The ship in front provided the streamlined water flow necessary at open sea, and also the propulsion.

So basically a catamaran, isn't it?
Stefan (Literary references to the discussed topics are always appreciated.)
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#8
Quote:So basically a catamaran, isn't it?

No, it is not at all! Catamaran is composed from two hulls connected together above water, whereas obelisk transport is composed of two independent hulls just supporting submerged obelisk so they are practically pontoons.
Martin
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#9
Maybe like this:

[Image: obeliskship.jpg]
Martin
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#10
...
MNI Gioi u F**ckers Smile <img src="{SMILIES_PATH}/icon_smile.gif" alt="Smile" title="Smile" />Smile
Remarks by Philip on the Athenian Leaders:
Philip said that the Athenians were like the bust of Hermes: all mouth and dick.
:lol: <img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" />:lol:
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#11
Unfortunately, we in Bohemia have no access to History Channel. Cry

Nemi ships story is too questionable, I saw those links too without excitement, and found them rather strange...

Thanks for your tips.
Martin
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#12
Many thanks Comerus!!! I thought the History Channel is only on TV.

I saw some videos, but have not found the Caligula's ships.

Oh, your post giving the link to History Channel on web disappeared !!?
Martin
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#13
The scale of the Nemi ships is daunting. In the basement of the Palazzo Massimo in Rome they have the end cap terminals to some of the timbers. Many are nearly two feet wide.

Alas, I couldn't get decent pictures.

Travis
Theodoros of Smyrna (Byzantine name)
aka Travis Lee Clark (21st C. American name)

Moderator, RAT

Rules for RAT:
<a class="postlink" href="http://www.romanarmy.com/rat/viewtopic.php?Rules">http://www.romanarmy.com/rat/viewtopic.php?Rules for posting

Oh! and the Toledo helmet .... oh hell, forget it. :? <img src="{SMILIES_PATH}/icon_confused.gif" alt=":?" title="Confused" />:?
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#14
...
MNI Gioi u F**ckers Smile <img src="{SMILIES_PATH}/icon_smile.gif" alt="Smile" title="Smile" />Smile
Remarks by Philip on the Athenian Leaders:
Philip said that the Athenians were like the bust of Hermes: all mouth and dick.
:lol: <img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" />:lol:
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#15
Avete omes,

For me the Discovery Channel program was real interesting. I had read a bit about the Nemi Ships but never payed too much attention to the details. Upon watching the program I was amazed at the finds and the sophistication of Roman naval engineering. And the fact that ships of that magnitude were being built in that era was just fascinating to say the least. What I am really exited about is how the reconstruction of these ships will turn out. Smile
aka: Julio Peña
Quote:"audaces Fortuna iuvat"
- shouted by Turnus in Virgil\'s Aeneid in book X just before he is utterly destroyed by Aeneas\' Trojans.
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