. The Locomotive. te remaining between the tubes, but also the failure ofall rivets in one way or another is required. This might be either E = [strength of net section of shell plate between tubes] -f- [shear-ing strength of all rivets]= [(P —D)t X TS] + [n X a X s]= [(7 — ) X 55,ooo] + [5 X X 44,ooo]= [224,500] + [230,600]= 455,100 lbs. or F = [strength of net section of shell plate between tubes] + [crush-ing strength of plate in front of all rivets] = [(P-D)tXTS] + [nXtXdXc] = [(7 — ) X 55,ooo] + [5 X 1-375 X X95,000] = [224,500] -f [755,ooo] = 979,500 lbs.
. The Locomotive. te remaining between the tubes, but also the failure ofall rivets in one way or another is required. This might be either E = [strength of net section of shell plate between tubes] -f- [shear-ing strength of all rivets]= [(P —D)t X TS] + [n X a X s]= [(7 — ) X 55,ooo] + [5 X X 44,ooo]= [224,500] + [230,600]= 455,100 lbs. or F = [strength of net section of shell plate between tubes] + [crush-ing strength of plate in front of all rivets] = [(P-D)tXTS] + [nXtXdXc] = [(7 — ) X 55,ooo] + [5 X 1-375 X X95,000] = [224,500] -f [755,ooo] = 979,500 lbs. Formula F can usually be neglected without computing its valuebecause its value, as a rule, is high. It is not advisable to do this,however, until one is thoroughly acquainted with riveted joint cal-culations. A comparison of the various values of B, C, D, E, and F shows 1925-] THE LOCOMOTIVE 135 C to be the smallest. The efficiency of the construction shown in Fig. 1,is therefore C 400,700A 5^0,000 = 75-6%.. I|. Rive* Holes. Fig. 2. Another type of reinforced tube ligament which is quite frequentlymet is shown in Fig. 2. Here we have two rows of tubes enter-ing the drum running parallel to, and alongside of, the butt seam. Inthis way double use is made of the cover plates, first, as butt strapsfor the seam, and second, as reinforcement for the tube ligaments. Themethod to be followed in analyzing this construction for efficiencyis similar to the one above. It should be noted, however, that someof the rivets here are in double shear. From the sketch, Fig. 2, we obtain the following dimensions: P = unit distance, that is, the shortest distance, measured along the drum,that will include a whole number of tubes and a whole number ofrivets = 7 inchesd = diameter of rivet holes = i%o inches = inchesa = cross-section area of rivets = SQ- inchest = thickness of shell plate = 1% inches = 1-375 inchesb = thickness of inside cover plate = 1^/2 inches = inchesbo = t
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Keywords: ., bookauthorhartfordsteamboilerin, bookcentury1800, bookdecade1860
