All structural steel of domestic origin. 24.2.1. Minimum 16’ clear/useable travel width between face of steel rails. 24.2.2. Minimum 16'- 0" clear/useable travel width between face of steel rails. 24.2.3. 60' overall/nominal bridge length. 24.2.4. Bridge shall be designedperthe AASHTO 2012 LRFDBridgeDesign Specificationsforthe following load criteria: 24.2.4.1. HL93 loading. 24.2.4.2. Six-axle/150-kip combination vehicle consisting of a 1Ok steer axle, two drive axles with 28k each, and three trailer axles with 28k each. Axle spacing shall be as follows: 0 - 14.25' - 4' - 35' - 5' - 5'. 24.2.4.3. Stringersshall be designed with no speed restriction [full impact loading]. 24.2.4.4. Design shall incorporate the dead load of a potential/future 3" asphaltoverlay. 24.2.5. P.E. stamped design letter of certification, drawings, and stringer/deck calculations shall be provided. Design shall be stamped by a PE licensedeitherin the state of bridge manufacture or the state of delivery. 24.2.5.1. The firm that seals the plans/calculations shall have an insurance policy in effect providing professional liability coverage for errors and omissions. 24.2.6. Allsteelshall be new, of domestic origin, and of minimum strength asindicatedin stringer calculations. 24.2.7. Welding procedures and personnel shall be qualified per AWS D1.5. 24.2.8. Full-dimension steel end plates [back-walls] of minimum 3/8" thick steel, provided at both ends to eliminate the need for a back wall on the abutments. 24.2.9. The guardrail system shall meet AASHTO requirements for pedestrian guardrails, except that railing height shall be increased to54". 24.2.9.1. Railing system shall consist of longitudinal steel rails. 24.2.9.2. The lowermost rail shall be capped with a treated timber rub-rail, with the interior face of the timber to be inside of the edge of the timberdeck. 24.2.10. Finish shall consist of two coats of epoxy primer with a urethane topcoat applied per the paint manufacturer's recommendations. Color will be Architectural Brown. 24.2.11. A 56-mil waterproofing membrane on 4-mil carrier film, slit to overhang the top flanges of the stringers by ¼" - ½" on either side, shall be pre-installed on the top flanges of all stringers. 24.2.12. Deck system shall consist of treated, nail or glue laminated, nominal 6" thick Southern Yellow Pine decking pre-assembled in panels. 24.2.12.1. Timbers shall be treated to UC4B "ground contact - critical components" and of minimum grade/strength as indicated in deck calculations. 24.2.13. Furnish all fasteners, hardware, and accessories necessary for superstructure assembly and deck installation. 24.2.13.1. Allstructural connections shall be made with galvanized A325 grade bolts or equal. 24.2.13.2. All clips/fasteners used with timber elements shall be galvanized orstainless. 24.2.14. Bridge shall be furnished with 1/2" thick neoprene bearing pads. 24.2.15. The bridgemanufacturer shall have at leastfive years' experience in the design andfabrication of prefabricated bridges. A brief narrative [3 pages +/-] shall be provided with the bid summarizing: 24.2.15.1. Supplier's qualifications/experience in the design and fabrication of prefabricated steel bridges. 24.2.15.2. Summary of a minimum of five similar projects. 24.2.15.3. Narrative of bridge system, including photos and/or sample drawings. 24.2.16. In addition to the PE stamped design submittals, the successful bidder should be prepared to submit the following items: 24.2.16.1. MTRs confirming material strengths and country of origin for structural steel. 24.2.16.2. Product data sheets on the paintsystem. 24.3. Stickers and/or copies of invoices [with pricing redacted] indicated lumber grade and treatment level.
