CATALOG OF THE MECHANICAL COLLECTIONS HJ 



provided that permit both sets of tubes to be expanded in the open- 

 ings in the castings. 



These improvements are said to be the results of the inventors' 

 experience with the boiler patented by them February 18, 1873, 

 no. 135877. 



DRUM-TYPE WATER-TUBE BOILER, 1929 

 U.S.N.M, no. 3(»870; model; gift of the Babcock & Wilcox Co.; not illustrated. 



This is a one-eighth size model of a Stirling 4-drum bent-tube 

 boiler, with superheater, air preheater, and water-cooled pulverized- 

 coal furnace. The boiler is rated at 579 horsepower and is designed 

 for 415 pounds steam working pressure and 250° F. superheat at 

 300 percent of rating. 



The boiler represented is approximately 56 feet high from the 

 ashpit floor and 35 feet from front to back. The boiler heating sur- 

 face is 5,790 square feet; the superheater 1,606 square feet; and the 

 air heater 7,350 square feet. The boiler is equipped with Bailey 

 walls and Bailey-Tenney burners. 



DOUBLE-DECK INCLINED-TUBE BOILER, 1929 



Plate 25 



U.S.N.M. no. 309869; model; gift of the Babcock & Wilcox Co.; photograph no. 

 32799A. 



This is a one-eighth size sectional model of a large inclined-tube 

 boiler, with interdeck superheater, air preheater, economizer, water- 

 •cooled furnace walls, and underfeed stoker. The boiler is rated at 

 1,658 horsepower and is designed for 375 pounds steam working pres- 

 sure and 677° total steam temperature. 



From ashpit floor to top of air preheater the boiler represented is 

 approximately 80 feet high by 35 feet from front to back. The boiler 

 has 16,583 square feet of heating surface; the superheater, 3,150 

 square feet. The boiler is equipped with a Webster furnace with 

 Baile}' furnace walls. It is fired by a Westinghouse underfeed stoker. 



SINUOUS BOILER HEADERS, 1867-1926 



PrATE 24, Figure 2 



U.S.N.M. nos. 309871-S09875 ; originals; gift of the Babcock & Wilcox Co.; 

 photograph no. 32809 (group). 



The group of sections of actual boiler headers shows important 

 steps in the development of the header from the cast-iron built-up 

 headers of 1867 to forged-steel headers designed for 1,400 pounds per 

 square inch pressure. 



The huilt-up tiihiiJar header of 1867 is made up of the single tube 

 ^nds cast on each end of each tube. The faces of the tube ends are 



