1. In mathematics
, a catenary
curve is the curve made by a chain suspended between two points, supporting a constant weight per length. It is the graph
- y = cosh x
This is not the same as the curve made by a chain supporting a constant weight per horizontal
length, as in a suspension bridge
; that is a parabola
2. A catenary structure consists of an overhead cable or cables used to deliver electricity to a railway locomotive, multiple unit, railcar, tram or trolleybus through a pantograph. An alternative system is a third rail.