Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. — Archimedes of Syracuse
The Trilithon and Transport of the Baalbek Foundation Stones
The transport of heavy stone blocks with human power in ancient times
By Henk J. Koens
A 1000 tons foundation stone. The people in the picture show the massive size of the stone block.
The foundation stones
These three collosal stones are situated in the wall and the remainings of the great acropolis of Baalbek, the Temple of Jupiter, in the Libanon built by the Romans.
The so called Trilithon composed of three stones each measuring 19 metres long x 4.2 metres high x 3.6 metres wide, hewn from crystalline limestone, weighing 870 tons each. They were transported from the quarry to the building site 1 km away and have been precisely positioned on a layer of 19 similar blocks weighing between 350 and 400 tons each.
The transportation weight of the foundation stones was even higher than 870 tons and went up to 1000 and 1200 tons. This has to do with the fact that the stones were redressed to a smaller dimension when they were placed in the wall, which was essential for a precise alignment.
What is not understood ?
It is still an unanswered question how the ancient Romans transported these huge megaliths because the technological ability to accomplish this is far beyond our comprehension, even in our time.
Scientists and archaeologists have proposed many methods based on ancient techniques but most of these methods were impractical or insufficient due to local circumstances or the enormous weight of the stones.
The French archaeologist Jean-Pierre Adam suggested in 1977 that the Romans used a set of 14 capstans with 448 laborers combined with pulleys and rollers to move the stones.
And how was the stone block quarried?
Was there a simple method of transport ?
It is possible that the Romans have used a forgotten technology to solve this transport problem.
We know that the Romans were very capable designers of watersystems, canals, high and long aquaducts. Running water was coming down from the hills in the Libanon and was at many places available. The question rises if the Romans may have used a waterway to transport these heavy stone blocks, perhaps with the aid of a ponton system, which could carry an extremely heavy load.
The geographical situation and an unique possibility for a canal
For the construction of the temple there was a unique situation. The building site of the temple and the quarry were located at the same altitude.
[Google map coordinates: Jupiter Temple (34.0068 N, 36.2035 E), and the quarry of the Trilithon blocks (33.9985 N, 36.1988 E) .
The terrain map with altitude lines gives a value of 1140m for these two places].
The fact that these two sites were located at the same height made it possible to construct a canal. By laying dikes which follow the hill at an altitude of 1140m, a canal could be created. This waterway started in the quarry and went to the building site of the temple and had a length of about 1000 m. This canal was closed on both ends by a floating ponton (caisson), which made it possible to gradually flood the quarry or the building site. Both areas could be emptied afterwards by opening the outlets (see next picture).
How were the stones quarried and where was the pontoon system installed ?
The workers started making a galery, large enough to accommodate the first ponton. Therefore they removed the bedrock on one side of the stone block, the material on the front, at the end and underneath. Four support blocks were placed under the stone block. Then they made a deep carve on the top backside of the stone block and placed wedges in the carve.
After a procedure of controled hammering on the wedges the stone block splitted and rested on the support blocks.
Then the galery for the second ponton could be made by removing the material on the other side of the stone block. Thereafter two pre-built pontons were positioned on both sides of the stone block.
Next a system of beams, ropes and iron bars in Lewis holes, strong enough to carry the heavy load, was installed. Now the stone block was ready for transport (see next pictures
How was the stone block lifted and transported ?
Hereafter the quarry area was flooded by gradually opening the water gate on the quarry side. The pontoon system was able to lift the huge foundation stone as soon as the water level was high enough and the whole assembly became a floating object. In this way it was easy to transport the stone block through the opened water-gate over the canal to the flooded building site at the end.
Easy navigation made it possible to reach the destination with great precision. By opening the valves in the pontoon, the foundation stone was sunk at the right place and the foundation stone came to rest on the lower foundation layer. The ropes were removed and the pontoon was returned to the canal. After closing the water-gate the building site was emptied by opening the outlet.
A perfect alignment could be reached by afterwards redressing the stone blocks and the Lewis holes are no longer present (see next pictures).
Positioning the stone block on the lower foundation layer by sinking it in the flooded area
-The unique geographical situation of the same level of the quarry and the building site, made it possible to construct a canal.
-The pontoon system could lift extremely heavy loads.
-The Romans had the knowledge about canals and aqua-ducts and they could build boats and pontoons.
So there is a good possibility that the Romans have used a canal to transport the foundation stones and perhaps also the other heavy stone blocks.
We will probably never know if the former ideas represent the real situation but it is clear that there is no mystery and that there existed technical methods to solve the transport problem.
The Romans were good architects and engineers and they will not have had too many difficulties to find the right solutions. Simple engineering techniques, human power, craftsmanship and a good management were the components. However, there is one special effect. The unique geographical situation that the quarry and building site were located on the same level made it possible that the Romans moved the world’s weightiest monoliths.
The Romans used “Lewis holes” to lift heavy stone blocks
Copyright 2012 by Henk J. Koens
All Rights Reserved.
Presented with author’s permission.
PS Archimedes’ Principle
Archimedes’ principle (or Archimedes’s principle) is a law of physics stating that the upward buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid the body displaces. In other words, an immersed object is buoyed up by a force equal to the weight of the fluid it actually displaces. Archimedes’ principle is an important and underlying concept in the field of fluid mechanics. This principle is named after its discoverer, Archimedes of Syracuse.
If we manage to place very large stone block in water, force to keep it floating will be much smaller than force required to lift it and move it on land. In addition, horizontal movement of such a block will also require very small force (since there is practically no friction).
Density of water (at +20 Co ) is 998 kg/m3 (nearly 1000 kg/m3)
Density of natural limestone has range from 2,100 to 2,900 kg/m3
So heavy stone block 1m x 1m x1 m instead of having weight of 1,000 kg appears to weigh only 500 kg when submerged in water.
If we add a buoyancy device made of seasoned & dry wood, for example Cedar of Lebanon with density 581 kg /m3 we can float 1,000 kg block of limestone using just 1.2 m3 of the wood !
This was the method most likely used to transport via Nile stone blocks from remote quarries for the Giza Pyramids, although ancient Egyptians probably used more efficient floatation devices made of much more buoyant papyrus.
Papyrus boats with the stones tided up underneath, waiting for high level of the Nile’s.
Copyright 2005-2006 by Andrzej Bochnacki.
Pyramids of Egypt are located near the shoreline of the ancient bed of the Nile. This image is based on information from David Jeffreys, Institute of Archeology, University College, London; Oriental Institute Computer Laboratory, University of Chicago and Archeological Graphic Services. NOTE: Vertical scale exaggerated to show ancient Nile river channel (on the left).