The designers found the solution in designing a single-span bridge carrying a double track, without the need for piers. The bridge consists of three parallel wrought iron arches resting on abutments on each bank, with the twin rail decks suspended by 14 wrought iron drop bars. It cost £16,000 to build. The bridge paved the way for new developments in bridge building – Newcastle's Tyne Bridge in 1928 and Sydney Harbour Bridge in 1932, being direct descendants of the design and construction of Hagg's Bridge.