Throgs Neck Bridge

Services: Existing Work Platform Inspection and Evaluation, Horizontal Lifeline System Design, Air Compressor Platform Design, Demolition Plans, Overhang Formwork Design, Steel Repair Details
Location: Bronx, NY
Owner: New York State Department of Transportation
Contract Number: TN-85C
Contractors: Skanska Koch, Inc.
EL Sol Contracting / El Sol Limited Joint Venture:

The Throgs Neck Bridge Suspended Span Repairs, TBTA Contract TN-85C, includes rehabilitation of the existing floor trusses, stringers, lateral bracing, connection plates, and other structural components.


Siefert Associates, LLC provides inspection services and engineered designs for temporary construction, tailored to the contractor’s preferred means, methods, and materials. The jointly developed solutions enable the contractor to complete the work efficiently while minimizing field labor costs. Examples of engineering services to date are as follows:


  • Existing work platform inspection and evaluation with a detailed report of suggested repairs and improvements, based on component analyze and material test results. The repair and reuse of the existing work platform was a financial benefit to both the owner and the contractor.

  • Design of a horizontal lifeline system for use by the contractor during repairs to the existing work platform. The lifeline system allowed the contractor to work safely across the full width of the bridge. The lifeline system was modular and was easily moved along the length of the bridge for complete coverage.

  • Design of an air compressor platform for use by the contractor during structural repair work. The platform cantilevers beyond the bridge fascia and poses no reduction in traffic or sidewalk width. Multiple platforms are installed along the length of the bridge, allowing the contractor to move the compressor to the area under construction.

  • Monthly maintenance inspections of the rehabilitated work platform. Regular inspections are conducted to evaluate the structural performance and durability of the work platform components.


The Throgs Neck Bridge Suspended Span Repairs contract is on schedule. Siefert Associates, LLC’s involvement and ongoing engineering support help to ensure safe working conditions.

EE Cruz:

EE Cruz’s involvement on the Throgs Neck Bridge involved the replacement of the concrete deck, the painting of structural steel, the completion of pier cap retrofits and the rehabilitation of the abutment & retaining walls. EE Cruz was able to complete the project in less than the ten stages originally specified. Siefert Associates, LLC assisted with the re-staging plans and also provided demolitions plans, including the analysis of equipment on the structure, overhang formwork design, and steel repair details to EE Cruz for the completion of a successful, on time project.








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