Sec. 76.23 



DESIGN OF SPECIAL-PURPOSE CRAFT 



791 



slips, adequate steering ability when running in 

 either direction 



(11) If intended to run in the open sea, enough 

 freeboard at the open end(s) of the car or vehicle 

 deck, or enough protection for that deck, at 

 both ends, to keep menacing quantities of water 

 off of it. 



M. E. Denny, in a paper "A Diesel-Electric 

 Paddle Ferry-boat" [lESS, 1934-1935, Vol. 78, 

 pp. 381-412], went to some pains to Ust the specific 

 design requirements which may be expected for 

 such a craft. Supplementary requirements are 

 given by F. L. DuBosque and E. A. Stevens in 

 two papers describing screw-propelled ferryboats 

 for New York harbor [SNAME, 1896, pp. 93-104 

 and Pis. 32-35; SNAME, 1893, p. 192]. 



Other useful references on this subject are: 



(a) Stevens, E. A., "Some Thoughts on the Design of 



New York Ferryboats," SNAME, 1893, pp. 192- 

 209 and Pis. 46, 57 



(b) DuBosque, F. L., "Speed Trials of a Screw-Propelled 



Ferryboat," SNAME, 1896, pp. 93-104 and Pis. 

 32-35 



(c) Stevens, E. A., and Paulding, C. P., "Progressive 



Trails of Screw Ferryboat Edgewater," SNAME, 

 1902, pp. 15-21 and Pis. 1-3. The following quo- 

 tations are taken in full from this reference, p. 15: 

 "The following is the approximate performance of 

 several vessels of this class at about that speed: 



W. L. DispL, Block Slip, Admty. 



Name Length, tons Coeff. per cent Coeff. 

 ft 



Bremen 217 900 



Cincinnati 200 952 



Netherlands 203 825 



Edgewater 173 687 



"The above data are close appro-ximations only." 



P. 17. 



"Dimensions of Edgewater: 



Length on water-line 173 ft 



Beam on water-line 34 ft 



Draught to base on trial 9 ft, 6 5/8 in 



Displacement to base on trial 687 tons 



Wetted surface to base on trial 5,764 square ft 



Propellers — diameter 8 ft 



Pitch, bow 10.03 ft 



stern 10.19 ft 



Projected area, each 26.4 square ft." 



(d) Stevens, E. A., "Progressive Trials of Screw Ferry- 



boat Bremen," SNAME, 1903, pp. 1-14 



(e) Stevens, E. A., "Some Problems in Ferry Boat 



Propulsion," SNAME, 1905, pp. 1-7 and Pis. 1-4 



(f) DuBosque, F. L., "A Fire-proof Ferry-boat," 



SNAME, 1906, pp. 7-29. The table on pp. 11-12 

 gives principal dimensions of ferryboat Hammonton. 



(g) Olsen, H. M., "Danish State Railway Ferries," lESS, 



0.34 16 154 



0.42 18.5 133 



0.36 18.5 144 



0.42 14.5 173 



1908-1909, Vol. LII, pp. 180-193 and Pis. X-XIV. 

 This paper describes and illustrates the ferries 

 Helsingborg, Storebaell, and Prins Christian. Table 

 I on p. 191 hsts the principal dimensions and 

 particulars of 22 Danish ferries; there are 12 

 entries per vessel. 



(h) Wyckoff, C. D. S., MESA, Oct 1921, pp. 750-751. 

 This article describes and illustrates the diesel- 

 electric ferryboat Poughkeepsie, which has its bow 

 and stern propellers carried at the ends of a fin 

 keel e.xtending below the hull; see also SNAME, 

 HT, 1943, Fig. 6, p. 170. 



(i) The Boston Harbor ferryboats Lieid. Flaherty and 

 Ralph J. Columbo are described and illustrated in 

 MESA, Nov 1921, pp. 826-830. The vessels are 

 174 ft long overall and 57 ft wide over the guards, 

 with a hull beam of 40 ft. The hull depth is 15.33 

 ft and the service draft 9 ft. The two propellers, 

 attached to two shafts bolted together amidships, 

 have a diameter of 7.5 ft and a pitch of 10.5 ft. 



(j) Kennedy, A., Jr., and Smith F. V., "Electric Propul- 

 sion for Double-Ended Ferryboats," Amer. Inst. 

 Elect. Engr., Pac. Coast Conv., Sep 1925. The 

 general conclusions arrived at in this paper are 

 reprinted in SNAME, 1926, pp. 225-226]. 



(k) Gross, C. F., and Green, C, "Some Considerations in 

 Design of Ferryboats," SNAME, 1926, pp. 217- 

 248 and Pis. 119-130. PI. 128 is a midship section 

 of the San Francisco Bay ferryboat Hayward. 



(1) Mitchell, E. H., "The Design and Propulsion of Fast 

 Double-Ended Screw Vessels," INA, 1928, pp. 

 88-102 and PI. X 



(m) Ferry Lymtngton with Voith-Schneider propulsion, 

 SBSR, 14 Apr 1938, p. 495; also 5 May 1938, pp. 

 590-591 



(n) Johnson, Eads, "Ferryboats," SNAME, HT, 1943, 

 pp. 165-196, 378-380, 386-387 



(o) Nordstrom, H. F., and Freimanis, E., "Modeli- 

 forsok med en Farja (Model Experiments with 

 a Ferry)," SSPA, Rep. 7, 1947. Summary in Enghsh. 



(p) Motorship, New York, Aug 1950, pp. 15-29, 36-43 



(q) S. S. Vacationland, Diesel Prog., Aug 1950, pp. 33-35; 

 also Apr 1952, pp. 42-45 



(r) SNAME RD sheets 27, 84, 100, and 150 



(s) Ferryboat Pvt. Joseph F. Merrell, MESR, Feb 1952, 

 p. 61, showing wave profile; also Dec 1952, p. 85. 

 This vessel is 290 ft overall by 277.5 ft on the 

 14.25-ft WL, by 69 ft over guards by 49 ft beam of 

 hull at 14.25-ft draft. Propeller Z) = 20 ft and draft 

 is 13.17 ft in normal operating condition. 



(t) Great Lakes carferries Spartan and Badger, Mar. 

 Eng'g., Mar 1953, pp. 42-57 



LoA = 410.5 ft 

 B = 59.5 ft 

 D = 24.0 ft 

 H = 18.5 ft 

 A = 8,860 t 



Cb = 0.656 



Ps = 7,000 horses, normal 

 V = ISmphor 15.66kt 

 Twin screws 



(u) Ferry Carabobo for Venezuela, Mar. Eng'g., Dec 1953, 

 p. 76; Dec 1954, p. 73 



LoA = 162 ft D = 12 ft 



Lpp = 161.67 ft H = Sh 



B = 42 ft A = 850 t 



