Västerbron, Steel arch bridge in Stockholm, Sweden

Västerbron is a steel arch bridge in Stockholm with three sections: over Riddarfjärden (two arches, 204 m and 168 m spans), over Pålsundet (276 m), and over Rålambshovsparken (243 m concrete slab). It runs from Södermalm via Långholmen to Kungsholmen, with a total length exceeding 600 m and a 26 m clearance under the main span.

The bridge opened in 1935 and was the second fixed connection between Stockholm's northern and southern districts. Structural modifications came in 1955 to add more bicycle lanes as traffic increased after World War II.

Västerbron appears in Stockholm's cultural life: Josef Kjellgren's 1935 novel Människor kring en bro is about the bridge's construction and its workers, and Beppe Wolgers wrote the line "På Västerbron, i den himmelska ron" for Monica Zetterlund's 1961 song Sakta vi gå genom stan. Since an eastern tradition took hold, couples have locked love padlocks on the railings; by December 2009 there were already about forty.

The bridge carries a 19-metre roadway flanked by 2.5-metre pavements, with a 26-metre clearance over the navigable passage. The section over Rålambshovsparken is a concrete slab on pillars, and the space beneath it serves as trailer parking in summer and boat winter storage.

The section over Pålsundet was the first major bridge in Sweden with a welded steel superstructure. The whole structure was assembled from parts built at Motala verkstad and at Ekensbergs Varv in Gröndal, and when it opened in 1935 it was the largest steel arch bridge ever built in Sweden.