COPYRIGHT TIM LOVETT 2003
An explanation of the AiG paper; "Safety of Noah's Ark in a Seaway"
Summary of Main Points:
The proportions and size of the ark are extremely seaworthy.
The ark could handle 47.5m waves before roll becomes critical.
Timber construction using 30cm hull and 50x50cm frame is adequate for 30m waves.
The ark is 13 times as stable as the ABS rules require - (for a passenger vessel).
The ark was assessed by comparing it with 12 different hull proportions, all with the same volume. The length, breadth and depth were varied by 20% and 50% as shown below. The original ark (No 0) had the best overall rating in terms of stability, comfort and strength. In other words, the Biblical dimensions are close to optimal.
Hull front and side views
|135||15||20.3||Unstable - capsize|
|135||27||11.25||Weaker and rougher|
|135||33.8||9||V. Weak & low (swamped)|
|112.5||22.5||16.2||2nd worst ride|
|162||18.8||13.5||Weaker & less stable|
|202.5||15||13.5||2nd weakest, unstable, nice ride|
The focus is on these three parameters:
Structural safety = will it break in half?
Overturning stability = will it capsize?
Sea-keeping quality = is the ride too rough?
In a general sense, you can improve these parameters by;
Structure: Stronger structure if ark is shorter and taller (e.g. Hull 5,6)
Stability: More stable if ark is wider (e.g. Hull 9)
Ride: More gentle if ark is longer and taller. (e.g. Hull 12)
You can see that the 3 dimensions - length, breadth and depth - are competing against each other. It is impossible to have the best of each parameter in a single design, but the ark gives the best balance of overall performance.
Note: A modern ship is closer to Hull 11. The ride is smoother and a steel hull withstands the extra length. Unlike the ark, ships are also designed to move through the water, so a more slender hull is preferred.
The Stability Misconception. (Don't get caught saying this...)
"The Ark is the most stable design"
Oops, not true. The Hong study ranks Noah's Ark 5th out of 13 in stability. You can calculate this yourself.