Any Civil Engineers here or carpenters with an understanding of lumber spans and the weight it can bear? I'm attaching some pics of a bridge across the creek on my property. It is solid and well built - the previous owner was a Civil engineer. I'm concerned if it will safely hold the weight of the tractor and attachments. The span is 12' supported with 4x4 posts with a 2x8 bolted through the 4x4 posts. the two center spans are 2x10. The two outer spans are 2x8. Everything is bolted together - no nails. I estimate the age of the bridge at 10-15 years.