Horseshoe Shape

The required input to define the size of a Horseshoe Arch is simply its Height or Rise (H). The remaining attributes are derived based upon tables internal to the SWMM implementation. Sometimes referred to as "Boston Horseshoe Arch", the unique cross sectional characteristics are based upon a top radius equal to half of its height. The definition of the bottom half of the arch is more complex and based upon internal angles

,

and