The lumber must be at least 8 inches thick and 8 inches wide. Place panels side by side with lumber covering any gaps between them. Advantages Operators can find materials for timber bridges at the site or purchase them locally or through commercial outlets. Little site preparation is needed. Structural characteristics are known and engineering specifications may be available for lumber or panels.
Operators can remove and reuse timber bridges several times.
Local water regulators generally favor timber bridges. Disadvantages Timber bridges may pose a safety hazard if operators don t get help from a licensed engineer or accurately assess the strength of logs and other construction materials. Logs, railroad ties, and demolition materials can have rot, knots, and other problems that affect strength. If operators don t use proper abutments, timber bridges may freeze into the ground during the winter. Surfaces may wear quickly during skidding operations.