God gave Noah specifications for how the ark was to be built. We do not need to assume Noah knew anything about ship-building. The instructions for design are given in Genesis 6:14-16:

If Noah started building the Ark soon after God spoke to him, then the process of building the Ark may have taken close to 120 years.

The Ark was shaped like a rectangular barge which floated rather low in the water. The ark was not really a "boat". It didn't need a power source to move it along (like sails), nor a rudder to steer it. It did not have any particular place to go. From the story in the Bible, it also would appear that Noah had no control over the vessel. It only needed to be sea-worthy for one year. He, and it contents were at the total mercy of God.

The Bible says the Ark was to be built of "gopher wood". What this material was is still a mystery.

The Ark was to be coated inside and out with pitch. It is believed that some oil may have existed before the flood, produced from non-biological sources. It was likely some resinous material used not only to waterproof the vessel but also to prevent decay.

It is given in cubits as being 300 cubits long by 50 cubits wide and 30 cubits high. A cubit in the Old Testament was generally about 20.5 inches. The Ark, therefore, could have measured from 437 feet to 512 feet in length! It was not until the late 19th century that a ship anywhere near this size was built.

The Ark had a ratio (length x width x height) of 30 x 5 x 3. According to modern ship-builders, this ratio (i.e. the ratio of length to breath is 6:1) represents an advanced knowledge of ship-building since it is the optimum design for stability in rough seas (Filby, Frederick A., The Flood Reconsidered, Grand Rapids: Zondervan Publishing House, 1971). The Ark, as designed by God, was impossible to capsize! It would have to have been tilted over 90 degrees in order to capsize.

With the shorter cubit the Ark would have an internal volume of 1,518,750 cubic feet, or the equivalent of 569 standard railroad boxcars. If the average sized animal was the size of a sheep it means the Ark could hold over 125,000 sheep. (Assuming the shape of the Ark to be rectangular there would have been over 100,000 sq. ft of floor space!)

The ark "window" was actually a long "slot" under the roof eaves. The phrase in Genesis 6:16, "Make a roof for it and finish the Ark to within 18 inches of the top." Most commentators believe it means leave an 18 inch space at the top that is open all around the vessel. This then would be for ventilation and illumination, and when water entered it would drain out somewhere below, similar to the vents in cars.

How were the animals for the ark gathered? It is clear from the scriptures that both Noah (Genesis 6:19; 7:2) and God (Genesis 6:20; 7:9, 15) were involved. God made the final decision about which pair of individuals of each type boarded the ark. One reason for this is that only God could know the genetic potential of each candidate, and it would be important that the individuals having the greatest genetic potential serve as the "founding pair" in repopulating the world.

There are other factors that make the gathering of the animals less of a problem than is commonly supposed. They are:

2. Warm climate throughout due to “vapor canopy” therefore animals were more evenly distributed;

The world before the flood may have consisted of just a single continent, eliminating the need for animals to cross oceans. The postulated water vapor canopy covering the earth at that time caused the whole earth to have a warm, tropical-like climate. In such a setting the different types of animals would have been more evenly distributed over the land, with each type capable of living almost anywhere. These two factors (single continent plus one climate) meant that all of the animals for the ark may have lived fairly close by.

Also, animals did not originally fear humans and only ate plants. This would have made them much easier to deal with. Both the fear of man and the allowance for animals to eat meat were introduced by God after the flood (Genesis 9:2-3).

Genesis 6:20 states the God brought the animals to the ark. The animals would have been easier to deal with in the ark if many of them were in a state of hibernation.

2 Peter 2:5 says 8 souls were saved. This means the people on the ark were Noah, his three sons (Ham, Shem, and Japeth), and their four wives.

In Genesis 6:19, Noah is instructed to bring mated pairs of every kind of bird, every kind of animal, and every kind of creature that moves along the ground. In Genesis 7:2, he is more specifically instructed to bring seven mated pairs of clean animals and seven pairs of all birds. Only air-breathing animals needed to be included on the Ark. There was no need for Noah to make any provision for sea animals. The animal passengers on the ark included:

Who exactly was on the ark? The large number of species of animals in existence today is often used to illustrate the supposed impossibility of the ark. According to the latest research carried out by John Woodmorappe, he reported that it was possible to contain all the required kinds of animals on the Noah's ark (John Woodmorappe, Noah's Ark: A Feasibility Study, Institute for Creation Research, 1996). The reasons are summarized as follows:

6. Up to maximum no. of 75,000 animals (or maybe as few as 8,000 if kinds only).

Dinosaurs would have been part of the cargo, but as with all animals that grow to be large, juvenile representatives would have been taken. In fact, the median-sized animal was about as big as a small rat.

It would have been sufficient to bring just representative animals from each "genus" in the taxonomic rank, not every species. All of the species for a given genus have the same amount of genetic complexity (just expressed physically in different ways, such as differing coloration or size), and both creationists and evolutionists agree that the variations identified as species can all be derived from a suitable common ancestor.

It was only necessary to bring aboard those animals that lived on land (land mammals, land birds, land reptiles, amphibians). Ernst Mayr, probably the leading American systematic taxonomist, lists the following numbers for animal species according to the best estimates of modern taxonomy (Ernst Mayr, cited in Dobzhansky, op. cit., p.7).

Animals	Species
Mammals	3,500
Birds	8,600
Reptiles & Amphibians	5,500
Fishes	18,000
Tunicates	1,700
Echinoderms	4,700
Arthropods	815,000
Mollusks	88,000
Worms	25,000
Coelenterates	10,000
Sponges	5,000
Protozoans	15,000
Total Animals	1,000,000

This eliminates 142,000 species of marine creatures. In addition, some mammals are aquatic (whales, seals); the amphibians need not all have been included; a large number of the arthropods (815,000), such as lobsters, shrimps and barnacles, are marine creatures, and the insect species among arthropoda are usually very small; and many of the 25,000 species of worms, as well as many of the insects, could have survived outside of the Ark.

As shown in the above table, Ernst Mayr estimates that there are less than 17,600 (say approx. 18,000) species of mammals, birds, reptiles, and amphibians living in the world today. We might double this to allow for extinct species. This would gives us 36,000 species times 2, or 72,000 animals. Adding for the clean animals, we might say there were as many as 75,000 animals. As we have mentioned in previous section 3.1.4.2, we said there was room enough in the Ark for 125,000 sheep, but most animals are smaller than a common house cat. There appears to be plenty of space for the preservation of the animal life.

Noah was instructed to include food for the animals (Genesis 6:21). The ark was that of intensive livestock confinement, where animals are raised in the minimum possible space with the maximum amount of labor saving devices employed. The ark was not intended to be an enjoyable experience for the animals (or the people!). It was, rather, a temporary captivity in which the only thing to be achieved was simply survival in reasonable health. There are many things that are doable for one year with survival as the only goal that could not be sustained for a long period of time. The three main ingredients for survival are:

Woodmorappe has calculated how much of the ark was needed to support each of these. A little less than one-half of the floor space (i.e. 47%) was needed to house the animals.

Food in the form of hay, dried fruit, dried meat, and dried fish occupied up to 12% of the ark volume. Most of the food was hay, compressed or possibly pelletized to take up less space.

Drinking water took up about 10% of the ark volume. This could have been less if rain water was also collected from the roof. Of course, all of the available floor space and most of the interior volume would have been used for some purpose (there may have been an animal exercise ring). The main point of the calculations is to show that the minimum amount of space needed was readily available. We still have 31% of total floor space available for other usage!

How to deal with the problem of animal waste? Woodmorappe estimated that 12 tons of wet excreta would have been produced daily (12 cubic meters) - comparable to intensive poultry house. Such problem may be handled by the following methods:

It would not be possible to clean each cage individually, nor would it be necessary if enclosures were employed. We must remember that Noah and his sons were smart people, and that they had a long time to prepare for the voyage. Extensive planning took place. Part of this planning was to design suitable enclosures for different types of animals, and to design them with the following labor-saving features:

Pests such as insects and rats could have been controlled through the use of ducks, cats and other animals that effectively control pest populations. Even though Noah is told to take two of every type of animal, this should be regarded as a minimum, and does not prevent him from taking, say, dozens of ducks and cats on board.

Earthworms provide another solution for getting rid of waste materials (they are natural biologic agents for the immediate biodegradation of manure).

God continued to keep special watch over the occupants of the ark during the Flood (Genesis 8:1). It is reasonable to assume that the animals' metabolism may have been slowed down during their confinement, even to the point where some of the animals may have gone into a state of hibernation by the supernatural power of the God.

Category	Tons
Empty Ark	4,000
Biomass at start	111
Biomass at end	411
Food at start	2,500
Water at start	4,070
Total needed	11,000
Cargo capacity	17,000
Spare mass	6,000

Woodmorappe estimates the ark contents by weight to show that the carrying capacity of the ark was more than enough for its cargo.

Biomass refers to the weight of the animals (and people). This increased significantly during the year as the animals grew bigger. Some reproduction would also have taken place. The increase in biomass would have been more than offset by the consumption of the food and water supplies initially on the ark.

According to the above reasons and calculations, it is feasible that a boat to carry about 75,000 animals of all genera could have been built, having adequate room for food and water, with the animals cared for by 8 people. God was involved to keep special watch over the occupants of the ark during the Flood (Genesis 8:1), but continuous miracles were not necessary.