NOTES ON THE PERFORMANCE OF THE S. S. TYLER. 



By E. H. Rigg, Esq., Member. 



[Read at the twenty-first general meeting of the Society of Naval Architects and Marine Engineers, held in 



New York, December 11 and 12, 1913.] 



The comparative scarcity of accurate and full accounts of the performances 

 of ships built in the various yards has frequently been deplored in connection with 

 papers read before this and kindred societies. This point came up in connection 

 with the short paper read here by myself last year, and it is more to follow up one 

 point then brought forward that the present paper has been prepared rather than 

 on account of any extraordinary interest or originality attaching to the following 

 remarks and figures. 



It is comparatively an infrequent occurrence for trial data of merchant ships 

 to be allowed publicity, and the thanks of the author are due to the Old Dominion 

 Steamship Company, the owners, and to the New York Shipbuilding Company, the 

 builders, not only for permission to record here the results achieved, but also for 

 co-operation in furnishing the information necessary for comparative purposes. 



In a paper entitled "Notes on fuel economy as influenced by ship design," read 

 before this Society at the general meetings last year, reference was made to the 

 vessel which forms the subject of the present paper. Certain hopes were indulged 

 in as to her performance as a coal saver, compared with similar vessels; since that 

 time she has been completed for sea, run her trials, and been in service long enough 

 for results to be available, and it is hoped that these will not be without interest to 

 members of the Society. 



Reference to page 233 and Plate 95 of our 1912 Transactions will give details 

 of the lines and of the model experiments carried out during the design stage of this 

 vessel. Later it was decided to build the vessel 331 feet long between perpendicu- 

 lars ; whereas a model representing a 308- foot 6-inch ship had been towed. This 

 change introduces a necessity for careful calculation to get the effective horse- 

 power for the longer ship. The curve of effective horse-power herewith has been de- 

 duced as follows: — 



Both ships were worked up from Taylor's standard series. A percentage dif- 

 ference between the model as towed and the shorter ship calculations was obtained 

 and applied to the longer ship calculations to get the required curve, which, there- 

 fore, represents the ship as built. 



In laying down the Tyler, middle body was added to obtain the new length; 

 the bilge lines were eased, so that there is, strictly speaking, no parallel middle body. 

 On the floor and sides, however, there is some fifty feet of parallel body, or 15 per 



