Contracted by UPRR to replace a failing / turn of the century wood pile structure over the Mill Creek stream. This project had plenty of time and logistical challenges. Being at the south end of the remote train yard where UPRR builds its trains on as many as 36 sets of tracks that converge down to 3 sets is the setting for this scene. Work was only allowed to be performed at the approval of a UPRR flagger, as trains were constantly moving through the work area. Setting up and altering the stream – Mill Creek – was required to perform the all work. Removal of existing stream bed was performed to allow for pouring of a concrete floor to set the new box culvert on. Sheet pile had to be driven to provide adequate support for train traffic during the work operation. Once complete, the tracks were allowed to be removed and a period not to exceed 48 hours began. The existing structure was removed along with all required soils to allow for a safe work area. The new pre-manufactured box culvert was set and backfilled with structural fill, compacted, ballast was placed and the tracks were put back in place. A total of 22 hours was required for completion of said work and turn over to UPRR to re-set the tracks. Additional work was required to finish the project after putting the tracks back in service. They consisted of a closure pour between the existing and new structure, a concrete apron, wing-walls, handrail installation, placement of rip-rap for bank and stream bed protection and the removal sheet pile and the pumps and piping utilized for the stream alteration.