When the bridge was refurbished in the 1930s, new steel girders replacing the ironworks were constructed inside the original bridge before the iron structure was removed. This allowed trains to continue running throughout the renewal process; however, the new bridge was no longer wide enough to carry two tracks. The northbound and southbound tracks were interlaced so that one rail lay between the tracks in the opposite direction, as points and a single track would have required a signal cabin on the north side of the viaduct.