Nile river boat

What I am trying to figure out is how big a boat is needed to carry a 70+ ton granite beam down the Nile from the Aswan quarry to Giza, a distance of some 580 miles. Obviously, steel, fiberglass and the like were not available to the ancient Egyptians, just wood and reeds.

Thanks for the help, Gerret

 

Really not that big, it all depends on the length. A vessel 15m long x 3.5m beam x 3m depth/ 2m draft will suffice for 70 tonnes depending on shape. So about something the size of the Pinta.

See here, for a previous study.
http://historicvessels.com/queen-hatshepsuts-heavy-lift-obelisk-river-barge/

 

Thanks. I had no idea how big it would be. I just saw the link for the barge - thanks G

 

Are those metric or imperial tons? A cubic foot of fresh water weighs about 62.4 lbs. That requires about 2230 cubic feet of displacement for the cargo. Making a wild assumption that the cargo is 50% of the displacement, let's use a round figure of 5,000 cubic feet of submerged volume . With a beam of 15 feet and a draft of 5 feet, the waterline would be 66 feet.

 

.... and we should talk about 580 nautical, land or ancient Nile miles.

 

I googled the distance from Aswan to Giza - the answer was 580 miles, but presumably it is as the crow flies. So going down the Nile would be longer. The Nile is fresh water, so it is less buoyant than sea water. So the vessel would have to be larger than a sea going vessel. G

 

Since the specified cargo does not have to be kept dry, consider slinging it between a couple of pontoons.
Keeping the cargo mostly submerged should greatly improve stability compared to deck cargo.
Hopefully the transit is downstream, so massive propulsion may not be required.

 

two points:
1) they probably weren't using a sealed hull, just logs and reeds, or earthen jars in baskets, or whatever, so the rig would be a lot bigger than just displacement figures.
2)cobbling together enough "stuff" to float a 100 ton object, or even stitching it together to handle a 100ton object, wouldn't be a big deal. But how did they load and unload from the barge?

I'm thinking they dug some underwater trenches in the mud into which were laid many ropes, then slide it into the water and pulled the ropes up and then attached many smaller floats to the ropes. On the other end of the trip it would be beached onto a "road" of longitudinal logs onto which other logs would be laid as rollers.

 

The Egyptians used one of the most sophisticated ship building methods on the ancient world, mortise and tenon, because they lacked the length of timber they needed to build large planked ships, but had access to hard strong timbers of shorter length as well as the manpower and time to construct them. These frameless vessel required less timber and volume than their displacement would suggest. It is a known fact that even large vessels, such as the Punt and funeral ships could be disassembled when required. As postulated in the paper I reference above, when moving a 70 to 1200 ton item, a canal was dug and most likely the vessel was constructed around the item to be moved. It is always important to look at the original user perspective …. we are doing this for a God, and we have eternity to finish it, manpower, time, and cost is not an issue.

 

A granite beam would require what kind of support ?

 

In the ancient world, when boats floated down a river like the Nile, how did they get back up river?river?
Sails, pull ropes, oars, paddles, push poles, etc.

 

Very carefully.

 

The same ways they did all over the world, use the tide, sail when they could, pull when they had to. Chinese Yangze and Russ Volga barges, US frontier Keelboats, Nile barges...all the same.

 

Ancient egyptians lucked out. The prevailing wind in the Nile valley blows inland. Ride the water current to the beach. Ride the air current to the jungle.

 

Yeah, but you had to haul at the first cataract. It was what divided the Upper Kingdom from the Lower Kingdom.
Cataracts of the Nile - Wikipedia https://en.wikipedia.org/wiki/Cataracts_of_the_Nile

EDIT: Phil Sweet was kind to point out I was wrong here; the First Cataract divides Upper Egypt from Nubia/Kush