Just east of Snohomish, the BNSF/ex-GN main line bridge over the Snohomish River had, until about a couple decades ago, a center-swing through-truss span designed to allow for passage of riverboats. It had been treated as a fixed span for many years, with the continuous rails laid permanently across the ends of the swing span. Between ten and twenty (?) years, ago BN replaced multi-span truss bridge with the current through plate girder spans, which obviously needed no movable portion.