Theoretical Naval Architecture Volume 2; A Treatise on the Calculations Involved in Naval Design

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1877 Excerpt: ...contains specimen calculations for ordinates of a curve of statical stability which are similar to the calculations for the surface statical stability at a finite angle which are given in Table II. The calculations shown in Table VII. are extracted from the appendix to the paper by Messrs. White and John, contained in Vol. XII. of the Tramsactions of tlie Institution of Naval Architects, which paper has already been referred to; and the work in them, is arranged in the manner usually adopted when calculating the stability at a number of successive angles for the purpose of constructing a curve of statical stability. As the calculations for the curve of dynamical stability are included in the same Tables, we will defer our explanation of them until we have briefly alluded to these curves. Plate XXVI. shows the body plan of the vessel to which these curves relate. 130. Curves of Dynamical Stability.--In Art. 72 it was shown that the dynamical surface stability at any angle 6 is equal to B(NBX-AB versin 6-A), (see fig. 1, PlateXVI.); and in Art. 89 the dynamical stability at that angle was found to be D(N'BX-GB versin 0). The object of the calculation for the ordinate of the curve of dynamical stability at any angle is to find the value of NB at that angle, and from this is deducted the product of the constant value GB (which is determined by the position of the centre of gravity), and the variable quantity versin 0, the difference being the whole distance that the centre of buoyancy is depressed and the centre of gravity elevated in inclining the ship over to that angle. Thus D(NBl-GB versin 0) is the mechanical work performed in inclining the ship. We have repeated these explanations, already given in Chap. III., in order that the student may readily follow ...