BNSF Bridge 253.89

BNSF Bridge 253.89 (Davenport, IA)

Type: Rim Bearing Swing Span
Location: Davenport, IA
Owner: BNSF Railway


Stafford Bandlow Engineering personnel provided engineering services for the complete replacement of the end lift machinery on this rim bearing swing span following the failure of the original system. The work included the replacement of the existing single roller system with a new double roller system. The rollers, roller supports, connecting linkages, power screw, open bevel gear set, speed reducer and reducer input shaft coupling were all replaced at both ends of the bridge as part of the project.

Prior to preparing the contract documents (plans and specifications), SBE conducted a detailed field investigation including deflection measurements and determination of loads at the four corners of the bridge using hydraulic jacks. This data was then used to ensure that the new machinery would operate within allowable stress limits while providing an increased reaction at the ends of the bridge. All detailed plans, specifications and calculations were prepared by SBE.

SBE worked with the railroad and the fabricator throughout the manufacturing process and was on-site during the winter closure to marine traffic. All work was completed with limited interruption to rail traffic.