The Locomotive . on several occasions, was not found in his boiler, and is henentirely omitted from consideration. The girth-joint cracks to which he con-fines his attention are of the three kinds that are illustrated in Figs. 1 and 2,which show sections of plate cut from one of the girth joints of the boiler de-scribed above; the section shown in Fig. 1 being cut from the inner course, orring, while that shown in Fig. 2 was taken from the outer course. Three kindsof such cracks are to be distinguished. First, cracks, like a, running circumferentially in the inner plate-ring, alongthe inner ro
The Locomotive . on several occasions, was not found in his boiler, and is henentirely omitted from consideration. The girth-joint cracks to which he con-fines his attention are of the three kinds that are illustrated in Figs. 1 and 2,which show sections of plate cut from one of the girth joints of the boiler de-scribed above; the section shown in Fig. 1 being cut from the inner course, orring, while that shown in Fig. 2 was taken from the outer course. Three kindsof such cracks are to be distinguished. First, cracks, like a, running circumferentially in the inner plate-ring, alongthe inner row of rivets thereof, and starting from the outer surface of the plate; Second, cracks, like b, also running circumferentially, but lying in the outerplate-ring, along the outer rivet-row thereof, and starting from the outer surfaceof the plate; and Third, cracks, like c, in the outer plate-ring, running in the general directionof the length of the boiler, from the outer row of rivet holes to the edge ofthe Fig. 3.— Diagram of the Affected Girth Joint. The cracks shown at a and b did not actually perforate the plate, but thecracks c ran through it from one surface to the other. The heavy calking markslhat are to be seen in the illustrations were not produced in the shop of themanufacturer, but were made subsequently by unskillful workmen, in the attemptto stop the leakage that had developed at these joints. Mr. Sulzer points out that the cracks that he shows could not have beenproduced by the steam pressure in the boiler, because the longitudinal joints,which were subject to much greater stress from this cause, were entirely un-affected. He also says: Nor can we properly regard them as ordinarytire-cracks, such as are formed when the heated shell is suddenly cooled in anyway, so that the superficial layers of the material shrink, while the deeper ones,cooling more slowly, retain their original dimensions, and thereby cause theexposed surface of the plate to crack open.
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Keywords: ., bookauthorhartfordsteamboilerin, bookcentury1800, bookdecade1860
