186 PRESENT STATUS OF THE CONCRETE SHIP. 



and as a carrying envelope for the steel. When reinforced concrete was first pro- 

 posed for building construction, only a few years ago, its use was prohibited by 

 many of our municipalities, and engineers looked upon the innovation with skepti- 

 cism. Today the structural steel building is the exception, and reinforced concrete is 

 accepted as one of our most reliable structural building materials. 



The first reinforced concrete cargo motor ship was designed and built by the 

 Fougner Concrete Shipbuilding Company at Christiania, Norway. It was of 400 

 tons deadweight and was launched in August, 19 17. This ship has been in constant 

 service for over one year, and a recent report states that it is giving thoroughly sat- 

 isfactory service and shows no cracks or defects of any kind. 



The concrete ship Faith, which is the pioneer American concrete ship, is of 5,000 

 tons deadweight. She was successfully launched in March, 19 18, made her maiden 

 voyage from San Francisco to Vancouver and return, passing through a severe storm 

 without showing structural weakness of any kind. She has since sailed with cargo 

 to Peru and has made a return voyage from Iquique, Chile, to New Orleans, via the 

 Panama Canal, with a cargo of nitrate. She now is bound for New York via Cuba 

 with a cargo of sugar. 



This ship has received the normal treatment of all ocean-going ships, having 

 sailed under her own steam, been towed, docked and dry-docked without evidence of 

 weakness. She will enter the transatlantic service upon completion of the present 

 voyage. The ship and cargo are both insured at rates only very slightly higher than 

 those charged for steel ships of the highest classification. 



The concrete ship is truly a product of necessity. We have been working on the 

 concrete ship comparatively a very short time and therefore we do not expect the 

 present ships to be the ultimate concrete ship ; they must be judged as pioneers, and 

 imperfections are to be expected. Since the concrete ship of large size (3,000 tons 

 and over) is being developed almost wholly in the United States, and mainly by the 

 Emergency Fleet Corporation, a discussion of the present status of the concrete ship 

 will be confined largely to a discussion of this work. 



In the development of the designs prepared by the Emergency Fleet Corpora- 

 tion, experienced naval architects and structural engineers have been employed. J. L. 

 Bates and F. B. Webster have furnished the lines for these ships and have been re- 

 sponsible for the necessary scientific ship studies. The concrete ship differs consider- 

 ably in weight distribution from other types of ships, and the structural material is 

 of such a nature that the concrete ship must receive special consideration and study 

 not ordinarily required in other ship design, in order to obtain the most economical 

 distribution of material for' the required strength, both from the standpoint of weight 

 and of construction. The girder strength is determined by the conventional methods 

 ordinarily used in steel ship design. The exact method employed is fully described in 

 a paper presented at Atlantic City at the meeting of the American Concrete Institute 

 in June, 1918.* In addition to these normal calculations very careful studies have 



♦"Problems Arising in the Design and Construction of Reinforced Concrete Ships," by R. J. Wig and S. C. 

 HoUister. American Concrete Institute, Junc„ 1918. 



