196 PRESENT STATUS QF THE CONCRETE SHIP. 



Architects (London) for 1918 contain two valuable papers which were contributed this 

 spring. 



The first paragraph in Mr. Wig's paper, summarizing the work being done at the present 

 time, is one which will attract the attention of this meeting. Doubtless there are many 

 points in Mr. Wig's paper' which will be commented upon, but there are two points to which 

 I should like to call attention. The first one is at the bottom of the first page, in which he 

 states that it has been necessary to devote much time to the theoretical analysis of the con- 

 crete ship structure, which is not undertaken at all in steel ship design. This statement ap- 

 pears to me to be unwarranted, as examples of laborious investigations into the structure of 

 steel ships are well-nigh legion. 



Now it is perfectly true, for every steel ship that is built, elaborate calculations are not 

 made, and why? For the simple reason that we have built so many that if we were to attempt 

 to figure out in detail the stresses involved in ordinary ships, which are perfectly familiar to 

 us, and of which we have built hundreds and thousands, we would be unwarrantedly wasting 

 time. That, I think, is a posiition which can be made good with regard to ordinary ships. 



Anyone who has seen the mass of data and the endless calculations on record in the 

 archives of the leading classification societies will know that Mr. Wig's statement is' incorrect. 

 I have seen some of the stress calculations undertaken at the time of the design of the Maure- 

 tania and Lusitania. I have also seen some of the calculations involved in the design of the 

 battle cruisers at present under contemplation for the United States Navy. These two ex- 

 amples do not stand alone by any means. Reference can well be made to the laborious inves- 

 tigations of the British Bulkhead and Load-Line Committees. The mass of data of excep- 

 tional value worked up vmder the auspices of those committees will serve also to refute the 

 statement. Perhaps Mr. Wig refers only to cargo ships of small size. 



Investigation into the question of oil steamer design (which class of ship represents, per- 

 haps, the most difficult of cargo-carrying vessels) will repay the seeker after light on the 

 subject of the investigations which have been undertaken in steel ship design. The work of 

 Mr. Isherwood alone in this field is tremendous, and his work has been supplemented by much 

 investigation on the part of those who have built ships under the longitudinal system of 

 framing. 



There is a book called "Structural Design of War Ships" by a fellow-member of this 

 Society, Captain Hovgaard. A very cursory perusal of this book will show Mr. Wig how mis- 

 taken he is in his statement. 



The transactions of this Society and of its sister Society, "The Institution of Naval 

 Architects" (London), to say nothing of the societies of Continental Europe and Japan, will 

 further show how unjust the statement is. 



Passing to the other side of the equation, namely, the forces set up by the sea and by 

 wave action in vessels, these questions have been the subject of extensive study, and if time 

 permitted I could quote a long list of papers, etc., bearing on the subject. It would take very 

 considerable time to merely read the titles of these investigations. 



It is toi be remembered that the concrete engineers inherit the whole of this field of inves- 

 tigation, which has been laboriously built up. by wood, iron and steel shipbuilders and those 

 associated with them in the development of the art. General technical science had not ad- 

 vanced as far when the steel ship began to sail the sea, and our concrete friends would do 

 well to recall this fact. They started in or about this present year of grace, with a field one 

 hundred times as well developed as that with which even the steel shipbuilders started. 



