We had the yarder in the Cowlitz River Tourist Attraction in 1987 ( I think that year?) The bridge said Load Limit 15 tons, the yarder weighed more and down into the river it went, with the bridge. It was a self propelled Washington something--big, and the yarder engineer went down with it, then popped up OK. Neither of the pilot pickup drivers could swim and they said it was a happy sight to see him pop up out of the river. The company had to hire divers to cut it up, and do an oil spill clean up. Shortly after that, they laid off their logging crews and then sold the mill and land. On another web site, I found out that the yarder was put back together and logged a few more years on the Olympic Peninsula.
It was a tourist attraction for a few days. The bridge was not replaced. And, had they made it over that bridge there was a weaker bridge to go over on that route.