630 feet

Now I am working on the chapter "Catenary" of the book "Mathematical Studies with Mathcad". See please one part here Catenary with load

I see that the value 630 feet  is very... magic value.

See please:

• Gateway Arch - Wikipedia, the free encyclopedia - an antycatenary
• The New York Wheel, A 630-Foot-Tall Ferris Wheel Planned for Staten Island
• http://demo.processwire.com/search/?height=630
• Etc - try please 630 feet on Google

What magic or someone others do we have in 630 feet - 192 m?

On picture from the book:

Werner! Where are you?