I was finally able to get into the "Dungeon" to make prints today. Heres a few of the shots we got. The checkers were where the carbon monoxide was burned off the flue gases and used to heat a checkerwork of bricks in the towers. Then air was pumped through to preheat it for the furnace. They had six of them, any two were heating air and the other four burning gases at any time to keep the furnaces supplied with hot air at all times. You can see some of the huge pipes to carry the flue gase to the checkers. The pump room had 20 foot diameter flywheels on the blowers and a jungle of smaller pumps I never learned what they were used for.
You can also see where I learned the purpose of that little strap with the D ring on the top of the bellows. You hang it on the hook on the back of the front standard to keep the sagging bellows out of the way of the film.