The Series 60 parent gave a lower resistance than the MARINER model over the useful 

 speed range, but above this the (C) curve turned up more rapidly, at least partly because of 

 the absence of the bulb. However, the Series 60 model was finer tJian the MARINER {C g 

 being 0.60 instead of 0.61), and to obtain a better comparison Uie MARINER model was changed 

 by removing the bulb, and the Series 60 parent resistance was corrected for the difference in 

 fullness and proportions by using Taylor Standard Series data. There was then no appreciable 

 difference in performance over the service and designed speed range. 



There was no essential difference in results in the case of SCHUYLER OTIS BLAND, 

 (Figure 25b), the slightly better (d) value of the SCHUYLER OTIS BLAND at the trial speeds 

 probably being due to the 2 percent bulb. 



The C.2 ship model (Figure 25c) was somewhat better than the equivalent Series 60 

 model by some 1 percent and 4.5 percent at the service and trial speeds respectively,- prob- 

 ably again partly due to a small bulb on the C.2. 



The Series 60 equivalent was some 1 to 2 percent better than the 0.70 Cg design, 

 (Figure 25d) in the neighborhood of the service and trial speeds. 



Several models of the PENNSYLVANIA (Figure 25e) were made at different times, some 

 in wax and some in wood. There was a certain amount of scatter in the results, influenced 

 to some extent by questions of turbulence stimulation. Over the useful speed range, this 

 difference amounted to some 2 to 4 percent, and the highest results for the PENNSYLVANIA ] 

 model were the same as those for the equivalent Series 60 model. i 



No modern cargo vessel design of about 0.80 block coefficient and of approved merit 

 was available for comparison with Series 60. A number of models with a variety of bow and 

 stern shapes were therefore made and run. The sterns were usually U-type, similar to those 

 of Series 60, and the bows ranged from U- to V-forms. In general, the models with the V-shaped 

 bows showed to some advantage, but they did not fit well into the cross-sectional area and 

 waterline contours since the other model lines were predominantly of U-type. The Panel was 

 of the opinion that seagoing merchant ships were unlikely to be built with such fullness coeffi- 

 cients. The somewhat fuller lake steamers would have m.uch greater — ratios than those 

 covered by the present series, and in fact were considered to be another problem. The 0.80 

 Cg model of the series could therefore be considered as really only an end point to which 

 the contours could be anchored. However, subsequent evidence suggests that the form as 

 finally adopted had some intrinsic merits of its own as well as being an "end point" to the 

 series. In the discussion on one Series 60 paper (Reference 45), Professor Baier said that 

 since block coefficients of 0.80 to 0.87 were of particular interest to the Great Lakes region, 

 he had carried out a series of tests with models in this range in the tank at the University of 

 Michigan. He reported that "seven models were designed with rather extreme variations in 

 sections at blocks of 0.857 and 0.872. At each of these block coefficients one form was 

 derived from the contours of Series 60, witii some adjustments in the forebody for lake-traffic 

 requirements. It is gratifying to report thpt these two models were definitely superior to the 



V-22 



