This is a much more attractive bridge than its next door neighbour, the footbridge discussed in the last post.
The London and Blackwall Railway was one of London’s first railway lines, completed in 1840 to connect London’s Docklands to the City of London. The engineer was Robert Stephenson, although the route was planned by John Rennie.
A contemporary account from 1840 states that the more typical arches are of 30 ft span, "constructed of five rings, but shew only three on the face, which gives the entire structure a light appearance". This is obviously wrong, with four rings being visible, but it would be no surprise to find that the arch barrel below the tracks is thicker.
The 1840 account also explains why the bridge has cast iron rather than solid brick balustrades: "iron standards of the railing, very properly introduced instead of solid parapets, the ill effects of which are daily experienced on the Greenwich Railway: the noise to passengers is of a stunning description".
The bridge has lasted well, and following the closure of the railway in the 1960s, it was revived as part of the Docklands Light Railway. As can be seen in the photographs, some of the piers have been festooned with small pipework, which I assume to be an ad-hoc attempt to direct water seepage in the piers to a suitable drainage system.