Brian - this is great info! Can you point me in the direction of any blueprint or graphic that would show the position of those fans in the 4th funnel? Many thanks!Yes, there were pipes in Kitchens which collected steam and the steam travelled upward and out of the funnel. A fan was suited inside the pipes to let the steam out quicker. There were also vents in the Kitchens which collected steam with a fan. The fan sucked in the steam and out of the smokestack.