. The Locomotive. te the sides at the lowest points of thedome, B and C, Fig. 2, and depress the point D. The result of this is to bring a severestrain on the shell and flange at the points B and C, which is usually very manifest intesting a new boiler to about one-third of its calculated bursting pressure. Thistendency may be resisted by putting in a stay bolt as shown in Fig. 2, or by other meansto be described further on. We do not advise the use of the stay bolt in new boilers,but old ones may sometimes be very much strengthened in this manner. Fig. 3 sliows the construction which should a
. The Locomotive. te the sides at the lowest points of thedome, B and C, Fig. 2, and depress the point D. The result of this is to bring a severestrain on the shell and flange at the points B and C, which is usually very manifest intesting a new boiler to about one-third of its calculated bursting pressure. Thistendency may be resisted by putting in a stay bolt as shown in Fig. 2, or by other meansto be described further on. We do not advise the use of the stay bolt in new boilers,but old ones may sometimes be very much strengthened in this manner. Fig. 3 sliows the construction which should always be adopted when the openingin the shell is the full size of the dome. The domes of locomotive boilers are usuallyattached in this manner and give little trouble, although subjected to very severe usage. 50 THE LOCOMOTIVE. [March, It will be noticed that the edgewise disposal of the material of the shell, by flangingupward, is admirably calculated to desist the depression of the shell at the point D, Fiff. Fig. 2. The most common form of dome connection is that shown in Fig. 4, by removingthe manhole frame, that is, the connection is made exactly as in Fig. 1, but the shell isnot cut away to so great an extent. The practice of different boiler makers varies inthis particular. Some cut one hole from six to twelve or fifteen inches in diameter,others cut several smaller the shell. This construction, although considerablystronger than that shown in Fig. 1, does not give an increase of strength in directproportion to the increased amount of iron left in the shell. This arises from the factthat both sides of it are subjected to an equal steam pressure, so that the material of theshell acts mainly as a bent stay between the points B and C, shown in Fig. 2. Still thegain in strength is very considerable, and where the workmanship is good, domesattached in this manner seldom give trouble at proper working pressures.
Size: 2430px × 1029px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorhartfordsteamboilerin, bookcentury1800, bookdecade1860
