Red Wing is where the shoe company was started, and the original factory is now an antique mall with some restaurants, etc. in it. Being a boiler inspector, the sitting area caught my eye. Its the remains of one of the original boilers. They just did a cut away. This was a horizontal return tube style firetube boiler.
The relief valves are mounted on the left. They would not meet todays codes. I've seen that style on an operating boiler once before. They had just been grandfathered in over the years and all the inspectors before me just let them go because they figured they were meeting the code from when it was installed. But I actually went up and checked the ratings, and they weren't even stamped for code use. I made them swap in new ones. I figured 64 years of service was a pretty good run on valves that normally should be replaced every 5 years or less.
That manway in the top can be a tight fit for anyone. Back then they were typically 10"x13" which I can't get through. I used to be able to get through the 11"x14", but my shoulders aren't as flexible as they used to be to squeeze through. I'm 5'11" and 232 lbs. Built more like a linebacker, not really much girth. Tight fit.
The bars on the upper part are called staybolts and re-inforce the tubesheet to the boiler shell. These were riveted, the whole boiler was riveted together.
You can see here how the staybolts hold the upper section of the tubesheet. The lower section uses the strength of the tubes as reinforcement. Flat plate is the weakest part of a pressure vessel.
These are just some pics of cool looking clouds as a storm was rolling into Waterloo, IA.
