 These projects resulted from the need to improve the structure for the beginning of CP service across the bridge with improved Series 070 locomotives on 1 November 1950.Following a decade of service, an analytic study in 1966 began to analyze upgrading service to electrical locomotives (Bò-Bó), leading to the end of the electrification of the Linha Norte.Verification, "in loco", determined stressed tests for the structure in 1969.