Background information
The bridge over Julianalaan was built around 1905 when the track plan for Haarlem station was laid out on a raised embankment. At the location of Julianalaan, with the waterway called Delft running parallel to it, a bridge with a clear span of approximately 19 meters was needed. Two abutments and a girder for each track proved sufficient. However, a new construction method for the girders was used for that time. Devised not long before by the Leuven chief engineer A. Vierendeel. The bridge is now over 120 years old but is holding up well. The underpass height is 3.60 meters. Sufficient around 1905, but nowadays a concern, especially for freight traffic.
Construction details
Thanks to the Vierendeel principle, cross-bracing in the girders is no longer necessary if the corners are sufficiently rigid. This girder is designed without a inspection path. The actual construction shows that the current inspection path was not original, which raises the question of whether the girders also functioned for part of their service life without an inspection path. This also happened on a completely different bridge, the Overlaatbrug. There, a footbridge was attached to the railway girders for a relatively short time, but disappeared quite quickly and never returned.
