How big was the Ark?
God told Noah, “The length of the ark shall be 300 cubits, its width fifty cubits, and its height thirty cubits. . . . You shall make it with lower, second, and third decks.” But what’s a cubit?
In the ancient world a cubit was a common unit of measure—the length of a man’s forearm, usually considered to be eighteen inches. That would make the ark 450 feet long, 75 feet wide and 45 feet high—one of the largest wooden boats ever built. It was shaped like a long box, not like a seagoing vessel built for speed.
The English Bible uses ark as a name for both Noah’s boat and for the holy box made famous by Indiana Jones in Raiders of the Lost Ark. But Hebrew uses two very different words for these two objects—and uses tebah only for Noah’s ark and for the basket in which baby Moses was placed by his mother. We don’t know if tebah means a boat, something covered in pitch, a certain shape, something that preserves life—or something else.
Noah’s ark had three decks with rooms, a door, and a window. Some point out there was probably not just one window, but a row of them just under the roof.
The ark was made of gopherwood—whatever that is. Translators had no idea what the Hebrew word gopher meant and so they merely transliterated it. The oldest Greek translation calls gopherwood “squared timber.” The most popular Latin translation calls it “smoothed wood.” Some have thought it is cedar or cypress. But the bottom line is . . . we don’t know.
God said to cover the ark inside and outside with “pitch,” probably for waterproofing, although there is no agreement on whether the pitch was an oil-based substance (as it is thought of today) or a gum-based resin extracted from trees, or something else.
How was the ark built?
Although the Bible says God gave certain specifications for the ark, it was Noah who had to design it—how to house the animals, where to build the living quarters for his family, what design elements would make the ark the most seaworthy. There is much speculation on how he did it, primarily by those who want to demonstrate it was possible.
For instance, Tim Lovett, an Australian mechanical engineer who has extensively studied the ark, says a long ship like the ark could ride out waves comfortably if it were to ride across the waves. But if it rode the waves sideways, the boat would roll dangerously and might even capsize.
Lovett suggests the ark may have had a projection on the front to catch the wind and a fixed rudder at the rear. The two would cause the ark to act like a weather vane, turning it into the wind so that it would ride across the waves.
Another problem is the seaworthiness of a wooden boat as big as the ark. Speed was not important, but Australian nautical archaeologist Tom Vosmer says, “It’s a safe bet that the huge ark would spring hundreds of leaks along the length of its huge hull and sink like a stone.” Large wooden ships built in the last 200 years were said to flex with waves to such an extent as to be noticeable. Such flexing would cause the wood planks to slide against each other, breaking the waterproofing seal.
The six-masted schooner Wyoming, built in 1909, had to use pumps to keep its hold relatively free of water because of such flexing. But perhaps earlier boat builders had a different approach.
Ancient shipbuilders used a labor-intensive approach to hull construction Lovett calls edge-jointed planking, a form of mortise and tenon joints. Noah also could have used more than one layer of planking and held everything together with wooden pegs, which expand and tighten when they get wet. And, of course, the boat was covered with pitch inside and out.
In the Ming Dynasty, Chinese treasure ships were reported to be the same length as the ark and twice as wide. They were the most technically advanced vessels in the world, and in the early 1400s they traveled to India, Africa, and perhaps even Australia. We don’t know if they flexed, but they were seaworthy.
However, some people question the validity of the treasure ships’ reported size “on practical engineering grounds” just as Vosmer questions the size of the ark because he thinks it would have sprung hundreds of leaks.
Was the ark round?
And why would anyone even think it was round?
In January 2014, the British Museum put on display a cell-phone-sized 4,000-year-old clay tablet from ancient Mesopotamia containing a detailed description given by the god Enki of how Atra-hasis was to build a boat and then—most interestingly—to bring in “wild animals, two each, two by two.”
It was to be a basket-like boat—similar to what ancient Mesopotamian people used and possibly similar to the “ark” in which Baby Moses was placed by his mother—and round, like a coracle. But unlike most coracles, this one was to have a diameter of almost 230 feet with 20-foot-high walls. It was to be made of coiled ropes supported by J-shaped wooden ribs. Atra-hasis’ boat was to have bitumen both inside and out for waterproofing.
What’s so intriguing about this tablet is the detail with which it describes the construction of the boat.
Irving Finkel, the British Museum’s Assyriologist who translated the tablet, explains, "It would be like a Bond movie where instead of having this great sexy red car that comes on, somebody starts to tell you about how many horsepower it's got and the pressure of the tires and the capacity of the boot [trunk]. No one cares about that. They want the car chase." This tablet gives the detail; the Bible gives the car chase.
Headlines such as “This ancient tablet says Noah’s Ark was round,” make about as much sense as to say Noah’s ark was a great canoe (the Ottawa flood story), a large house (a flood story from pre-Colombian Mexico), or a boat pulled by a fish (a Hindu flood story). What such headlines do effectively is to sell newspapers or websites.
Unfortunately the archaeological importance of this tablet may get swallowed up in the promotional hype.
Noah’s ark? The Bible says it was 300 cubits long, 50 cubits wide, and 30 cubits high. Atra-hasis’s boat? It was round.
 Noah’s Ark: The Real Story, BBC, 2003.