Bob,
Just one thought that came to me (I get 1 or 2 a year :D)…
How hard would it be in a separate RR construction/status forum to allow posts and comments as we do now except to give the author access to it (his own log only) once a month to delete posts not relevent to the subject? This would allow current discussion for a 30 day period, and longer at the author’s discretion, without wading through a lot of posts no longer relevent. Also someone coming onto the site a year or two later would be able to have questions, suggestions posted and answered directly and then eventually deleted if they didn’t have overall relevence.
The forum would have to be monitored to keep its new subjects exclusively on member’s railroads but that would have to be done I would think regardless of how the forum was set up. Too, with the author doing the moderating for his article (in addition to Bob’s normal monitoring of course) it would save Bob a lot of work trying to keep things on subject. As for the few that wouldn’t monitor their own RR log…that’s going to happen with some anyway.