. Supplement to Spons dictionary of engineering, civil, mechanical, military, and naval. sses dueto the total dead or permanent load will be obtained ;— Stresses due Stresses due Resultant Stresses to Weight to ^Vater due to Total of Dock. Ballast. Permanent Load. Tons. Tons. Tons. At centre - 143 - 654 = - 797 50 ft. from „ - 124 - 585 = - 709 100 ft. „ „ - 67 - 381 = - 448 150 ft. „ „ - 12 - 102 = - 114 To ascertain the effect of the weight of a perfectly flexible long ship, heavy in the centre butlight at the ends, two assumptions are made as to the distribution of the weights. The weight o
. Supplement to Spons dictionary of engineering, civil, mechanical, military, and naval. sses dueto the total dead or permanent load will be obtained ;— Stresses due Stresses due Resultant Stresses to Weight to ^Vater due to Total of Dock. Ballast. Permanent Load. Tons. Tons. Tons. At centre - 143 - 654 = - 797 50 ft. from „ - 124 - 585 = - 709 100 ft. „ „ - 67 - 381 = - 448 150 ft. „ „ - 12 - 102 = - 114 To ascertain the effect of the weight of a perfectly flexible long ship, heavy in the centre butlight at the ends, two assumptions are made as to the distribution of the weights. The weight of the ship is assumed to be proportional to its displacement at each section of itslength. This weight is plotted on a diagram, and the weight of each portion is calculated, aud thedistance is ascertained of its centre of gravity from any point round which moments have to betaken. The ship in this example is taken as 381-9 ft. long x 44*7 ft. beam, and displaces on aneven keel, and at an 18 ft. draught, 3944 tons of water, its gross registered tonnage being3664 tons. Taking the same four points in the length of the dock as before at which to calculate thestresses, emd calculating for each of those points the downward moments of those parts of the shiponly which lie beyond that point, the moments due to the weight of the ship are found— Foot-tons. At centre = - 125,334 50 ft. from „ = - 47,880 100 ft. „ „ .. .. = - 10,134 150 ft. „ „ = - 316 The displacement caused by weight of ship is 3944 tons total, or -^f^ = 9 • 86 tons a foot run;and the moments of this displacement are;— Tons. Ft. Ft. Foot-tons. At centre 9-86 x 200 x 100 = -1- 197,200 50 ft. from „ „ X 150 X 75 =+110,925 100 ft. „ „ „ X 100 X 50 = + 49,300 150 ft. „ „ „ X 50 X 25 = + 12,325 The following algebraical sum of the moments due to the weight of the ship and to the dis-placement caused by this weight will give the resultant moments due to the ship; and dividingha
Size: 2640px × 947px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectenginee, bookyear1879
