Sky-N-Sun - Bridge Design

Suspension Bridge Design Considerations and Math
Catenary

The term Catenary is derived from the Latin word for chain. It is a formula for describing the shape a chain will take if supported at each end and allowed to hang freely between these two points. For maximun strength, we want the cables of the bridge to follow this shape.

The Catenary formula is: Y = ( A * cosh( X / A ) ) - A
Where:
X = Distance from the point where the cable sags to its lowest point.
Y = Height of cable at distance X above its lowest point
A = think of it as a sort of focal length and units conversion constant
If the towers are at the same altitude, X will be zero at the center of the bridge.