Mance: Quarry Industry of Southern Indiana 



67 



Diameter of boiler 



Number of tubes 



Diameter of tubes 



Thickness of shell 



Thickness of head 



Braces above tubes 



Braces below tubes 



Size of steam pipe 



Size of feed pipe 



Size of blow-off pipe .... 



Heating surface. . . 



-D ^ ^ V, /16 ft. 



Rated horse-powerj 



Grate surface 



Diameter of 60-foot stack 



48 in 



54 in 



60 in 



66 in 



72 in 



24 



36 



44 



54 



68 





4 in. 



4 m. 









16 m. 



16 m. 



3% in 



3% in 



/8 111- 



16 m. 



72 All. 







in 

 16 in. 



12 



20 



ou 



OU 



■dtU 











g 



3 }/2 in. 





4 3^ m. 





6 in 



1 in 



1 111. 



1 lyf in 

 1 >4 in. 



1 3^ in. 



1 3^ in. 



1 1^ in 



1 X2 in. 



2 in. 



2 in. 



2 in. 



2 in. 



2 in. 



520 sq. ft. 



715 sq. ft. 



864 ft. 



1042 



1325 



585 sq. ft, 



805 sq. ft. 



972 ft. 



1270 



1490 



43 3 



59 5 



72 



87 



1 10 



48.7 



67 



81 



90 



124 



14 sq. ft. 



18 sq. ft. 



21.6 sq. ft. 



30 sq. ft. 



33 sq. ft. 



15.8 sq. ft. 



22 sq. ft. 



24.3 sq. ft. 



33 sq. ft. 



39.6 sq. ft. 



24 in. 



27 in. 



30 in. 



33 in. 



36 in. 



The following are standard specifications for a boiler 72 

 inches by 18 feet, working pressure 125 pounds, as given by 

 Professor Bissell (/oc. cit., pp. 159, 160): 



Type. — Horizontal return-tubular. 



Dimensions. — 72 inches in diameter, 18 feet long from outside to outside 

 of heads, with smoke extensions 18 inches long continuous with the shell. 

 Thickness of the shell, y% inch; thickness of head, Yi inch. 



Material. — Best open hearth flange steel, having a tensile strength of not 

 less than 57,000 nor more than 62,000 pounds, and ductility corresponding 

 to 56 per cent reduction of area and 25 per cent of elongation. All plates 

 in finished boiler to show stamp with name of maker, quality, and tensile 

 strength. 



Riveting. — Triple-riveted butt joints for longitudinal seams and single- 

 riveted lap joints for girth seams. 



Tubes and braces. — 68 tubes 4 inches in diameter, 18 feet long, best lap 

 welded or seamless drawn, carefully and properly expanded with Dudgeon 

 expander, and beaded at each end. Braces: 40 braces above tubes and 

 4 below tubes; the former crowfoot form, flat or round, of not less than 1 

 square inch in area at smallest section, the latter \yi inches in diameter, 

 with upset ends for 13^-inch thread at front and crowfoot connections at 

 back, with turned bolt \^ inch in diameter. No brace less than 3 feet 6 

 inches long. 



Details of the tube sheet layout to be according to practice recommended 

 by the Hartford Steam Boiler Inspection and Insurance Company. 



Supports. — 2 lugs on each side. Front lugs to rest on cast iron plates, 

 others on rollers and plates to permit of expansion. All plates 12 by 12 by 



1 inches. Rollers 1 inch diameter, and 9 inches long, 3 at each plate. Or 



2 suspension loops on each side, of 13^-inch round iron securely riveted to 

 sliell. Columns and double channels for overhead suspension, with equaliz- 

 ing I-beams at back end. 



Construction. — No dome. Shell in 3 rings, each ring formed from a 'single 

 sheet, horizontal seams above the fire and to break joints. Heads machine- 



