The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

86 sections. Some bodies ordered and accepted their sections purely on the basis of dimensions and weight per foot run, independent of thickness; other bodies ordered and accepted the material only on the basis of di- mensions and thickness, independent of weight, while others again at- tempted to work on both systems at once. The committee, therefore, when publishing for the first time the sizes and sections, recommended that they be ordered by the leading outside di- mensions and thickness, or by the leading outside dimensions and weight per foot run, but not by both. Full Particulars of Sizes and Form. it ts obvious that in<such a com- paratively rough manufacturing pro- cess as that of rolling sections (where a slight difference in some dimension may produce a _ disproportionate crease or decrease in weight) to tie makers down to produce standard sec- tions with extreme accuracy, both in regard to dimensions and weight, is an unnecessary hardship, and would increase the cost without any propor- -tionate benefit to the ship builder. As very considerable interests and sums of money are involved by the intro- duction of standards, especially in an important industry such as the pro- duction of rolled sections for ship building purposes, the committee felt that the best interests of all concerned would be served if steel makers were given early intimation of the proposed standard sizes, together with particu- lars of their dimensions of ordinary manufacture--an opportunity should be afforded to return them in accord- ance with the proposed standards. To meet this view the committee pub- lisked, at as early date as possible, full particulars of the sizes and form of profile of the different sections. The calculations involved in the preparation of tables of moments of inertia, radii of gyration, etc. occu- pied a very considerable time in view of the care necessary inthe production of such tables, and while those tables were in course of preparation steel makers without any brusque change of policy were enabled gradually and at the minimum cost to bring their rolls into line with the new standards. Co-operation Between User and Roll- ing Mill. I venture to hope that the co-op- eration which has existed in my com- mittee between the various specifying interests, those concerned in the pro- duction of the sections and those re- sponsible for their utilization in the construction of ships, has been the means of enabling each to appreciate in-. introduction of special THe Marine REVIEW the difficulties which the other has to overcome, though the interests must necessarily sometimes be of a con- flicting nature. Evidence which has been collected by the committee has brought out the fact that the recom- inendations in regard to standard sec- tions have been widely, if not univer- sally, adopted by the rolling miils of this country, and that when standard sections are adhered to, promptness of delivery and dispatch are the re- sult. In days gone by it was no uncom- mon thing for the rolling mills to approach the ship builder and to sug- gest numerous alterations in the list of sizes, This may have been due to the request by the ship builder for sizes which, though aavertised in the makers' section books, had become obsolete, or may have been due to the sections to meet special requirements, but I would take this opportunity of urging upon my confreres, when preparing designs and subsequent lists of sections, to ad- here as closely as possible to the standard lists, as they. are thereby studying their own interests in regard to delivery and cost, through saving time and trouble at the mills. A practical instance of how co-op- eration between user and rolling mill may either facilitate or hinder produc- tion is aptly illustrated by an instance cited by Sir John Wolfe Barry in his lecture before the Institution of En- gineers and Ship Builders in Scotland in December, 1908, of an architect desiring to use about 200 tons of a non-standard section which differed only in very minor details from the nearest standard section. The contrac- tors asked permission to substitute the nearest standard section, but were not allowed to do so, with the result that a set of special rol!s costing about £200 had to be cut and the price of the 200 tons was increased by this amount. Thus the architect's clients had to pay £200 extra for the privil- ege of using a non-standard section which, with a small amount of give and take, should have been saved. Opposed to Chemical Tests. The divergence which existed inthe tests called for when the committee began its operations was consider- able, the requirements of the various bodies crossing and re-crossing, so that if material had to be tested to pass two of the inspecting bodies, it became a matter of considerable dif- ficulty on account of the narrowness of the limits available. The frst gen- eral discussion showed clearly that the committee were entirely against specifying any chemical tests for = May, - plates and sections. They decided thit suitable mechanical tests, such as had been applied heretofore, combineq with practical working in the factories was all that was necessary, and that the chemical composition of the ma- terial was the concern of the many- facturer, who had to produce his ma- terial in such a way that it would pass the practical and stringent tests specifi d. This view did not com- mend itself to all sections of the standards committee, and though the necessity for a chemical analysis had not been felt by such an extensive user of steel as the British admiralty, nor had the experience of the classj- fication societies pointed to the desira- bility of having one, it was deemed advisable to follow the line of least resistance and, in the case of material for other purposes than ship building, for which it had been customary tv stipulate a chemical analysis, such a requirement has been incorporated in the standard specifications. Some of the existing rules called for a longer test piece than that rep- resented by 8 in. between the dabs, which requires an over-all length of about 16 in., and the steel makers estimated that the restrictions of all test pieces to this length would effect a very considerable monetary saving, so that it was decided to make 8 in. the standard distance for all plates and sections. Alternative. Standard Test Piece. In dealing with round bars, a gage length having a ratio of. eight times the diameter has been adopted as giv- ing a roughly comparable elongation with that of the plate specimens, and when the bars are turned down it is stipulated that the length of the par- ~ allel portion shall not be less than nine times the diameter in order to eliminate the influence of the shoulder and larger ends of the test piece. At a subsequent date the committee were approached by the steel makers with a request that provision might be made for the use of a shorter test piece in the case of bars having 4 diameter of over 1 in., because in the case of boiler stays many of the steel works had testing machines which were capable of breaking such bars without having them turned down, but the length of the test piece was t¢- stricted by the distance between the grips. It was urged that a great Sav- ing in material and in cost of prepa- ration would be obtained by the adop- tion of a shorter test After careful consideration and experiment it was decided to provide an alterna- tive standard test piece (test piece be piece,