The Locomotive - Lighthouse Survival Blog

66 THE LOCOMOTIVE. [May,
2.25 —0.93? =1.313 "; and the thickness of the blade being £", it is evident that the
area resisting fracture along AB, in Fig. 1, is only
1.313" xi. "--0.656 sq. in.,
or only about two-thirds of a square inch. The weakest part of this brace is therefore
across the line AB ; and at this point it falls decidedly below the requirement of the
specifications.
p1G> 2. The Weakest Section.
:
It is much better to make the blade of a
brace | in. thick and 2f in. wide, when it is
1| in. in diameter in the body. This will give a
considerable margin of safety across the rivet-
hole, as is easily seen by repeating the foregoing
calculation with these new data. We do not
wish to be understood as requiring these particu-
lar dimensions, however. We are satisfied if the
requirement of the specifications with regard to
minimum sectional area is fulfilled, no matter whether the dimensions are precisely as
here indicated, or not; but we wished to draw attention to the fact that boiler-makers
often overlook this very simple yet very important matter of having a sufficient sectional
area across the rivet-hole in the blade, and to say that a more careful attention to it in
the future will save a good deal of time and trouble to all concerned.
Inspectors' Report.
January, 1901.
During this month our inspectors made 11,820 inspection trips, visited 22,331 boil-
ers, inspected 6,742 both internally and externally, and subjected 758 to hydrostatic
pressure. The whole number of defects reported reached 12,734, of which 1,238 were
considered dangerous; 59 boilers were regarded unsafe for further use.
mary is given below
Nature of Defects.
Cases of deposit of sediment, -
Cases of incrustation and scale, -
Cases of internal grooving, - - - - -
Cases of internal corrosion, - - - - -
Cases of external corrosion, - - - - -
Broken and loose braces and stays, - ------
Settings defective,
______ ____--
Furnaces out of shape,
-
______
Fractured plates,
Burned plates,
Blistered plates,
Cases of defective riveting, - ______
Defective heads,
Serious reakage around tube ends, - - - -
------
Serious leakage at seams, -
Defective water-gauges, -
Defective blow-offs,
Cases of deficiency of water, -
her use.