Norfolk Southern Bridge B184.50

NS - B184.50 (Cleveland, OH)

Type:  Span Drive Vertical Lift
Location: Cleveland, OH
Owner:  Norfolk Southern Corporation

This project began as an in-depth inspection and engineering evaluation of the main counterweight wire ropes and associated support components of this span drive vertical lift bridge. It subsequently included design and engineering services during construction.

All sheave trunnion bearings were opened for inspection. SBE personnel performed a thorough visual inspection of the bearing journals, directed magnetic particle testing of the fillets and directed longitudinal wave ultrasonic testing of the trunnions.  SBE conducted a stress and fatigue analysis for the main trunnions to determine remaining service life.  No defects were found in the inspection and the analysis indicated that the trunnions had ample service life remaining.  The in-depth inspection of the wire ropes revealed extensive corrosion at the splay castings and rope terminations.  Analysis of rope section loss due to corrosion indicated a significant reduction in strength resulting in a safety factor that fell far short of meeting AREMA requirements.  The ropes were in need of replacement.

SBE prepared a complete set of plans, specifications and cost estimates detailing the replacement of all main counterweight ropes and terminations.  SBE provided construction service to facilitate interaction between the Contractor and Railway to ensure that the requirements of the contract plans were met.  A significant feature of the design was that all field work had to be completed during a six week bridge closure to marine traffic. Additionally, Railway service could not be interrupted.  SBE reviewed shop drawings, performed source inspection of new components and provided continuous on-site inspection and time-line management of critical path activities throughout the six week outage.