God's command to build what is called Noah's Ark is found in the sixth chapter of Genesis.
14. Make an ark of cyprus timbers ('gopher wood' in the KJV and other translations) . . . you shall pitch it inside and outside with pitch. 15. And this is the way you shall make it: The length of the ark shall be three hundred cubits (a cubit is roughly equivelant to 18 inches or 45 centimeters today), the breadth of it shall be fifty cubits and its height thirty cubits. 16. You shall make a window . . . and you shall finish it to a cubit from above; and you shall set the door of the ark in the side of it. You shall make it with lower, second and third stories. (Genesis 6:14 - 16, HBFV)
The above model of Noah's ark was created at a scale of 1/75. The other vessel shown in the photo (Columbus' ship named the Pinta) and the railroad car have also been created on a 1/75 scale. The actual length of the stockcar is 44 feet (13.4 meters) and has a capacity of 2,670 cubic feet (75.6 cubic meters). The ark's volume was 1,518,000 cubic feet (42,985 cubic meters), which would be equal to 569 of the above pictured cars. Strung together, they would stretch an amazing five and one-half miles (8.85 kilometers) long!
The above model is based on the assumption that the Biblical cubit was, using our modern system, 18 inches (45.7 centimeters). If a larger cubit is assumed the model would be proportionally larger.
Something to consider
God was quite particular in how he wanted his ship built. He told Noah what its dimensions should be, the wood to use, how to seal it so that it was water tight, where to put a window, etc. One very critical component, however, is not mentioned at all in its planning or construction.
How do you steer it?
A rudder is a vertical object added to the back or stern of a boat that can be manipulated such that it steers the vessel. The Bible does not record its was suggested, or that God stated, that a rudder be built. While the absence of any steering capabilities on the ship is far from definitive, the inability of humans to be able to navigate it could easily be symbolic of great spiritual principles.
Without the ability to steer the ship, it would be left to travel wherever the wind, weather and currents take it. Even if he wanted to, Noah would be powerless to direct it away from any perceived dangers or obstacles like trees, rocks, waterfalls, swift currents, hills, mountains, etc. as the flood waters rose and fell.
The operation of Noah's Ark would, of necessity, require absolute FAITH that God would be the ship's rudder and that He alone could steer it from danger and lead it ultimately toward safety. It is no wonder that Noah was among the very few listed by the apostle Paul in Hebrews 11 as being a pillar of faith and an example of the kind of trust God wants all of us to have in him.