This is a railway bridge crossing West Street in Gateshead, on the approach to the High Level Bridge.
It has lattice trusses, installed between the wars, which replaced an early and unusual form of box girder construction, built c.1848. Each box girder was made of riveted wrought iron plates. Sandwiched between these at the top was a cast iron beam, to which the plates were riveted. There were bosses at intervals along the cast iron beams to accommodate wrought iron hanger rods which supported cross beams carrying the deck. The nearby Half Moon Lane Bridge (Gateshead) was of similar construction, but of smaller span.
See here for a detailed drawing of West Street Bridge. This shows that the transverse beams supporting the deck comprised wooden beams sandwiched between wrought iron plates, the asssembly being riveted together. Decorative cast iron capping was fitted over the top of the flanges and on the outboard side of the bottom of the girders.
The design and construction is most unusual, and fortunately a section of the girder removed from the Half Moon Lane Bridge is on display Discovery Museum, Newcastle, although it is wrongly identified as being from the High Level Bridge. The wrought iron plates of the Half Moon Lane box girders were parallel, whereas at West Street the spacing decreased from the bottom to the top. Also the cast iron beams at West Street were of H section (the H on its side), whereas the Half Moon Lane bridge beam castings appear to be of channel section.
John Rapley recorded that a third bridge of this genre was built over the Great North Road near Alnwick, but that little was known of it. In fact a photograph here shows a bridge of this type, albeit with relatively shallow girders, located over South Street, near Alnwick.
1849 'A small railway station is about to be erected for the convenience of passengers going South or coming North from Gateshead. It will be situated at the Southern extremity of the High Level Bridge, near the junction of the lines between tbe Half Moon Lane and the New Street, and will be completed in a short time. Messrs Wilson and Gibson are the contractors. A new box girder bridge, from the establishment of Messrs. Robert Stephenson and Co Stephenson, is in the course of erection over West Street; the span of the bridge is 94 feet 6 inches, and the girders 112 feet each.'