Yeah, Calahan has kindly explained it to me. For those who are interested:
*** Begin Explanation ***
I''d let you know that Iron Walls only works if it is cast before a siege is in progress. It is literally worthless if you cast it during a siege.
The wall strength from Iron Walls gets directly added to the wall strength in the fort info screen. So if the fort had 250 defence then the display would say 450 while Iron Walls was in effect. If the wall strength this turn went from 46 to 56, then that means you repaired the walls, and you should have got a message saying (or words to these effect)
"Fort X is under siege, but they can not harm our walls"
and the other guy should have got a message saying
"Fort X is under siege, but the defenders are repairing the walls faster than we can knock them down."
*** End Explanation ***
Also, I see you've been using that Tardis to go back and forwards in time again, dude. Funky. I only mentioned Iron Walls AFTER I cast it, but you (being the clever dude you are) knew about it BEFORE I cast it - and cunningly didn't tell me! You are so cool - here is a trophy for your efforts, as you are clearly one of nature's born WINNERS!
