52 : ECONOMICAL CARGO SHIPS—SOME MODEL EXPERIMENTS. 
p= ae X .466=.2741. 
Therefore fore body C,=1.0—.192=.808. After body C,=.726. 
Thus the vessel should be 550 feet X 64 feet 5 inches X 28 feet 7 inches draught 
CHotiship)— 707% C, of fore body = .808. C, of after body =.726. 
(Ge = .980. L. C. B.=.463=254.7 feet aft of F. P. 
Height of transverse metacenter=.023B below WL=27.1 feet above base. 
CV3A3 : . 
Bi, lel, P= ina C=.730—.018 (Length correction, Fig. 2, Plate 16). 
-712 X 4096 
E. H. P. == = 534 I. 
546 534 
This power would be reduced by increase of draught until 6=.485 at which 
E. H. P.=5,220 but there would also be a reduction in KM and stability. 
If it is necessary to locate the L. C. B. differently it is possible from the dia- 
grams to estimate the increase in H. P. due to this. If L. C. B. were moved 15 
feet farther aft the power would be increased by 200. 
DISCUSSION. 
Tue CHAIRMAN:—Paper No. 4, ‘‘Economical Cargo Ships,” is open for discussion. 
This paper represents a great deal of work, and I am sure you feel indebted to Mr. 
Robertson for the pains he has taken to supplement his previous valuable paper by this 
one. I hope there are some members here prepared to discuss the paper and to give 
some added light on this subject. Perhaps Dr. Sadler will discuss the paper. 
Pror. HERBERT C. SADLER, Member of Council:—I would like to draw attention to 
one remark on page 44 of the paper, which is as follows: ‘‘These experiments were all 
carried out for the Emergency Fleet Corporation, and it is by their courtesy that they 
have been made available for publication today.” In these days of criticism of everything 
connected with the Shipping Board, perhaps it is rather interesting to note that after 
all, that branch of it known as the Emergency Fleet Corporation did do something in 
the way of constructive experimental work, which we hope will be for the benefit of 
the shipbuilders of the country. The results of these experiments are made public in 
this paper by Mr. Robertson today. I may say that there is another series of experi- 
ments which we have just completed, which will also be published at a later date. The 
results are well worthy of careful study. 
I remember some years ago we tested two models, one after the other, in the tank 
at Ann Arbor. I was rather astonished to find that the one with the smaller prismatic 
coefficient drove harder, a good deal harder, than the one with the large prismatic 
coefficient. It seemed not quite right. In those days we had not carried out many 
