As built, the bridge consisted of three wrought iron spans of , each located on top of two sandstone abutments with foundations at a depth of about below water level. The trusses support the metal bridge deck, which carries the railway lines. The erection of the lattice girder spans was unusual, because instead of floating the finished sections down the river and lifting them into position, each was built up piece by piece in situ. There are six lattice girders, two for each span. Each girder contains around 700 tons of iron and is fastened by 48,115 rivets. During the first half of the 20th century, some of the wrought iron girders were replaced by steel counterparts.