Specifications include, but are not limited to: Stringers – Shall be 10 in. x 18 in. Full Sawn, Douglas Fir/Larch, Select Structural. After fabrication, incise and pressure treat timbers in accordance with AREMA Volume 2, Chapter 7 and AWPA UI using creosote meeting Use Category UC4B (contact with ground exposed). The vender shall submit the following certifications and reports to WSDOT for acceptance prior to delivery. A Manufacturer’s Certification of Compliances certifying the stringers meet the requirements of AREMA Volume 2 Chapter 7 and the Treatment Inspection Reports for creosote. Piles - Shall be Coastal Douglas Fir, 12 in. tip diameter x 10 ft. and 14 in. tip diameter x 10 ft. Piling shall be cut from sound, live trees and shall contain no unsound knots. Sound knots will be permitted, provided the diameter of the knot does not exceed 4 inches, or ⅓ of the small diameter of the pile at the point where they occur, whichever is smaller. Any defect or combination of defects which will impair the strength of the pile more than the maximum allowable knot will not be permitted. Piling shall be cut above the butt swell and shall have a uniform taper from butt to tip. A line drawn from the center of the tip to the center of the butt shall not fall outside the center of the pile at any point more than 1 percent of the length of the pile. A spiral grain or twist in excess of ¼ turn in 10 feet of length will be cause for rejection. Timber piling shall have an average of at least five annual rings per inch measured radially over a distance of 3 inches at the butt, beginning at a point 3½ inches from the heart. At least 9 inches of heartwood shall show at the butt. After fabrication, pressure treat timbers in accordance with AREMA Volume 2, Chapter 7 and AWPA UI using creosote meeting Use Category UC4B (contact with ground exposed). The vender shall submit the following certifications and reports to WSDOT for acceptance prior to delivery. A Manufacturer’s Certification of Compliances certifying the piles meet the requirements of AREMA Volume 2 Chapter 7 and the Treatment Inspection Reports for creosote. Ties – Shall be 7 in. x 9 in. x 10 ft., Timber shall meet the requirements of AREMA Volume 1 Chapter 30 Part 3 and Standard Grading Rules for West Coast Lumber for No. 1 – Railroad Ties.