Reading a thread below reminded me of an article I read regarding the effects of applying cold water to an overheated crown sheet.<br>I dug it out, and the basics follow. <p>The article appeared in the December, 1910 issue of Railway and Locomotive Engineering, and referred to a test conducted<br>by the AT&SF. This particular test utilized a Jacobs-Shupert firebox, but reference was made to conventional firebox<br>construction as well. <p>The safety valves were set for 225 psi and the boiler was oil fired. Once the safety valves lifted at 225, a blow-off cock was<br>opened and the water allowed to fall to four inches below the highest point of the crown sheet. It was allowed to remain there<br>for 10 minutes while the fire was maintained. The pops continued to blow, reducing the water to six inches below the crown<br>sheet, with an average pressure of 230 psi.<p>After the 10 minutes, the fire was extinguished, and cold (60 degree F.) water was pumped in until the glass was two-thirds<br>full. Just before the water was pumped in, pyrometers recorded a temperature at the front of the crown sheet of 1125 deg. F.,<br>and at the rear of the crown sheet 1065 deg. F.<p>According to the article:<p>"The most important lesson of this test, of course, is the proof that the prevailing belief is a fallacy, that cold water pumped<br>upon hot sheets would cause a boiler explosion. The same thing has been demonstrated several times. About 1870, upon the<br>advice of Mr. Francis Stevens, of Hoboken, N.J., the United States Government conducted a series of tests of boilers in<br>which high pressure and intense temperature was employed until the boilers exploded. No bad effects resulted from pumping<br>cold water upon hot sheets. The Pennsylvania Railroad Company also carried out exhaustive experiments to show the effect of<br>intense pressure on boilers and the damage done by pumping water upon red hot sheets. When excessive pressure was<br>employed on boilers full of water they exploded; when cold water was pumped upon red-hot sheets, the sheets contracted and<br>leaked, but no explosion resulted."<p>It would be interesting to know if there have ever been any tests that suggested otherwise, or if the whole idea of explosions<br>caused by introducing cold water is just an old wive's tale. <br>



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