This boiler was 5' in diameter, 23' long, built for 250 lbs. working pressure. It never had a hot crown sheet while I owned it.
106 South Elm Street, Newkirk, Oklahoma 74647
Lately there have been gruesome stories about boiler explosions and scary tales of foaming boilers and I am almost afraid to attend a steam engine show. What if some 'engineer' were to pump water on to a red hot crown-sheet? Or maybe accidentally get a spoonful of milk in his water tank?
Now, I want to tell a little tale about a dry boiler that didn't explode. In the tall white oak timber of the Arkansas Ozarks back about 1934, a good stave mill operator named John McKew, was running a stave mill. One day everything was going nicely, but somebody noticed that there was no water showing in the glass. The fireman had become careless or perhaps a check valve had failed to close. Anyway somebody hollered 'turn on the injector' but another yelled 'no, no, it'll blow sky high if you do.'
John McKew was the kind of fellow that never was scared for a full minute in his life, so he took command. He said, 'Now you all get behind the sawdust pile. I'm 76 years old anyhow and it can't beat me out of much, and I'll turn the pump on.' He did just that. Nothing happened, and before long the water showed in the glass. The careless fireman built up his fire and got up a head of steam, and the mill resumed making staves.
Now understand that I'm not advising anybody to turn on the injector when the water is out of sight. It is best to cover the fire with wet ashes. Drawing or dumping the fire will create an intense heat that will do more damage or perhaps cause an explosion. Getting a crown-sheet hot is sure to cause some damage, so DONT LET THE WATER GET LOW.
Now I will tell a story of a hot crown-sheet that had much more serious consequences.
The Missouri & Arkansas was a short line railroad that ran from Southwest Missouri to East Arkansas. They had about a dozen locomotives. The M. & A. was never very profitable, but during World War II, they had plenty of business and were hard pressed for power. At this time, with war material needing to be moved, Engine No. 50 was allowed to pull a train out of Harrison, Arkansas, just two hours after the time for its regular I.C.C. inspection. This might not have caused any trouble, but after the train reached Marshal, Arkansas, about forty miles to the Southeast, No. 50 blew up. The boiler front, a disc of steel seven feet in diameter and one inch thick, as a spectator said, sailed through air like a straw hat. The crown-sheet pulled loose from the top of the flue sheet and tore loose from the side sheets two-thirds of the way back, the crown sheet seemed to have been soft as a blanket. Now the incredible part: it closed off the fire door and neither the engineer nor fireman was seriously hurt, although the forward part of the grates were blown out.
My brother, Dewey, and I were operating our saw mill about a couple of hundred yards from the R.R. shops and we were well acquainted with most of the shop men and the road men. I don't aim to mention any names as some of the descendants of the men involved might read this.
They pulled No. 50 onto a siding between the R.R. shops and our mill, and the I.C.C. inspectors took over. The water glass was still about one-third full of water and they used considerable pressure to blow the obstruction out. They measured the water in the tender and found that they had only used about one-third as much water as would have been needed to pull the train that distance. All the evidence showed that the engine crew had driven that engine with a dead water-glass right under their noses and melted the crown-sheet. For nine inches down from the top of what was left of the fire-box, the soot was all burned off of the steel until it looked like a rusty heating stove. The inspectors said that when a locomotive blew its crown-sheet, it usually somersaulted in the air; but in this case, the sheet pulling loose at the front, caused the steam and hot water to go forward, and the soft crownsheet closing off the fire door, saved the engineer and fireman, while the reaction held the rear end of the boiler on the frame. If the sheet had pulled loose at the back, the engineer and firemen would have been vaporized.
After the inspectors left, I crawled in through the opening where the grates had been, and looked the wreck over. The crown stays were still hanging to the wagon-top, tight and sound at the top end, but practically melted off at the bottom end.
However, the trouble had just started; the road men against the shop men. Of course the boiler foreman had violated the law when he let the engine leave the round-house after the inspection was due, and the road men were trying to put the blame on him. The poor man was so worried that he blew his brains out with a six-shooter, right by the side of the round-house. He was a fine man, a very competent boiler maker, and a very good friend of mine.
This disaster points out one of the most important duties of the operator of a steam boiler: always be sure that the connections to the water glass are open and water shows in the glass before starting a fire. The lower drain should be opened and the glass blown out at least once a day, and much oftener if the water is dirty.