Specifications include, but are not limited to: A. Timber. All bridge ties and timbers shall be solid-sawn and treated Southern Pine or Douglas Fir Grade No. 1 or better. All ties and timbers shall meet the requirements of Chapter 7, Section 1.7 “Specifications for Timber Bridge Ties” of the AREMA Manual. All ties and timbers shall meet or exceed the allowable unit stress values for wet conditions, visual grading shown in AREMA Table 7-2-9. Bridge ties shall be surfaced two sides (s2s) on the top and bottom sides, and dapped (notched) on the bottom side as shown in the Plans. B. Preservative Treatment. All timber shall be Dual treated with 1# Borate and 6# Creosote preservative in accordance with the requirements of Chapter 30, Section 3.6 “Wood Preserving” and Section 3.7 “Specifications of Treatment” of the AREMA Manual. Minimum creosote preservative retention shall be 6 pounds creosote per cubic foot of timber for all members. The preservative treatment to be used shall be Borate/Creosote as outlined above.
