This was the cause of the Gettysburg Railroad firebox explosion[8] near Gardners, Pennsylvania, in 1995, where low water allowed the front of the crown sheet to overheat until the regular crown stays pulled through the sheet, releasing a great deal of steam and water under full boiler pressure into the firebox. Next, let's have a look at ESP decisions. So in the case of a large locomotive which can hold as much as 10,000 kg (22,000 lb) of water at a high pressure and temperature state, this explosion would have an theoretical energy release equal to about 1,160 kilograms (2,560 lb) of TNT. [notes 1] Such investigations helped him and others explain the importance of stress concentrations in weakening boilers. "[5], Boiler explosions are common in sinking ships once the superheated boiler touches cold sea water, as the sudden cooling of the superheated metal causes it to crack; for instance, when the SS Benlomond was torpedoed by a U-boat, the torpedoes and resulting boiler explosion caused the ship to go down in two minutes, leaving Poon Lim as the only survivor in a complement of 54 crew.[6][7]. Reference Library #59) Stationer's Hall, London: International Textbook Company (sec.12,p.76), Milo D. Koretsky, “Engineering and Chemical Thermodynamics”, John Wiley & Sons, 2004, p. 508, Milo D. Koretsky, “Engineering and Chemical Thermodynamics”, John Wiley & Sons, 2004, p. 509, Graham, Frank D. (1945) "Audel's Power Plant Engineers guide" New York, Ny: Theo Audel and Co. (p.332-333, figure 55: "corrosion along the water line due to air"), Boiling liquid expanding vapor explosion (BLEVE), "Benlomond (British Steam merchant) – Ships hit by German U-boats during WWII –", "STEAM LOCOMOTIVE FIREBOX EXPLOSION ON THE GETTYSBURG RAILROAD NEAR GARDNERS, PENNSYLVANIA JUNE 16, 1995", "IDO-19313 "ADDITIONAL ANALYSIS OF THE SL-1 EXCURSION" November 12, 1962. No automated method has been found yet that has this reliability. By using this site, you agree to this use. [14][15] Eventually the simple lap seam was replaced by the single or double butt-strap seams, which do not suffer from this defect. However, 14% were in the upper furnace, 13% in the superheater area, 11% in the generating bank area, and 8% in the lower furnace. Several written sources provide a concise description of the causes of boiler explosions: "The principal causes of explosions, in fact the only causes, are deficiency of strength in the shell or other parts of the boilers, over-pressure and over-heating. One type is a failure of the pressure parts of the steam and water sides. "[2], "Cause.-Boiler explosions are always due to the fact that some part of the boiler is, for some reason, too weak to withstand the pressure to which it is subjected. It is highly successful and later becomes the modern TÜV. A steam explosion can occur in any kind of a water heater, where a sufficient amount of energy is delivered and the steam created exceeds the strength of the vessel. Galvanic corrosion was an additional problem where copper and iron were in contact. Boiler and pressure vessel-related deaths in North America decreased in 1996, perpetuating the cyclical trend of the past five years. -St Mary's Hospital, Pennington Avenue, Passaic, New Jersey: Cleaver Brooks boiler Explosion 7/15/2006. When it comes to number of accidents, there is little positive news. They are liable to fail through fatigue (because the inner and outer walls expand at different rates under the heat of the fire), from corrosion, or from wasting as the heads of the stays exposed to the fire are burned away. [18] This can occur when crossing the summit of the hill, as the water flows to the front part of the boiler and can expose the firebox crown sheet. A later investigation concluded that the 26,000-pound (12,000 kg) vessel had jumped 9 feet 1 inch (2.77 m) and the upper control rod drive mechanisms had struck the ceiling of the reactor building prior to settling back into its original location"[10]. Due to the constant expansion and contraction of the firebox a similar form of "stress corrosion" can take place at the ends of staybolts where they enter the firebox plates, and is accelerated by poor water quality. Several different attempts were made to cause a boiler to explode by various means, but one of the most interesting experiments demonstrated that in certain circumstances, if a sudden opening in the boiler allowed steam to escape too rapidly, water hammer could cause destruction of the entire pressure vessel: "A cylindrical boiler was tested and withstood a steam pressure of 300 pounds without injury."