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: | ' August, 1909 THE Marine REVIEW New Method of Steel Hull Construction TEEL vessels as generally de- signed and built for carrying lumber or other bulky cargoes have two principal disadvan- tages; exhib- iting in the extreme a.tendency to longitudinal weakness, break in two, and lack of sufficient ballast capacity to make trips through stormy seas in safety when running without cargo or with -high deck loads. If sufficient 'ballast is provid- ed to make the vessel stable when light, then the double 'bottoms are so deep that with a full load the center of grav:ty of the ship is too high, almost as high as the meta- center, making a very tender vessel. An extreme case of these conditions is found in the lumber trade of the Pacific coast where the vessels are loaded southbound and light north- bound, at both times being subject to heavy coastal seas. Many attempts have been made to evolve a design of ship for this trade or for similar con- ditions met elsewhere which would be equally satisfactory at all times wheth- er loaded or light and regardless of conditions. To weather solve this 7 Saye ~~ TERE * ee ne ak Sih ' ' ~~ = eo Ga AOS 4 WINCHES Fic. 1--Prans or Lumser SCHOONER Fittep WiTH CENTRAL TR problem effectually is unusually diffi- cult. Ships have been proposed and some have been built with ballast tanks arranged. under the decks or-on the sides. We present herewith draw- ings showing a new system of con- struction designed by Edward C. Hough, San Francisco, which is claim- ed to obviate the objections to the usual systems of ballasting. The feature of the design is a cen- tral trunk or longitudinal double bulk- head extending from the fore peak to. the engine room, so built as to stiffen the hull longitudinally, in the direc- tion in which it is weakest, and also to provide high and low tanks for fuel oil which can be also used as bal- last. A vessel has been designed em- bodying these principles, the plans and. -cross séctions. of ~which. are shown herewith. The vessel is 295 ft. 6°in, In-leneth : Over -all,..276 tt10 length between perpendiculars, 48 ft. molded beam and 21 ft. molded depth. This steamer has the usual equip- ment sof a. steam sehooner: -a 1,600 H. P. triple expansion engine and two Scotch marine boilers, each 15 ft. in diameter and 11 ft. 6 in. long; a sub- POrE ek E : PORTABLE 2 pin Bowk ' " 4 wea \ i i | ny ily {I ql rr i 1 may t 1! 1 il i wily il tty i i ATCH ' wal Wt "71 i 'y HIGH TANK" 3 O1L FUEL Low TANK "3. OM FUEL y, Lidhet hy pat yt iN ! { iI ty Wy fl it yall ---- 400 -- Ie 20/04 >- ee -- ke --2b+0'- >< -- --40'o_ ---- 4 ALL CARCOBOOMS 60-0 LONG. WIGH TANK "2 Olk FUEL ae Lowrank "2 OILFUEL 261 merged tube donkey boiler 7 ft. in diameter and 11 ft. long: a towing machine; six sets of cargo gear and six cargo winches. The central trunk, referred to above, is simply a double longitudinal bulk- head which divides the hull into two complete holds. The space between these bulkheads, which are not usually over 4 ft, apart, is utilized for fuel oil tanks. Each of the two holds are 21 it. 6 in. wide in the clear, 180 ft. in length and 16 ft. deep. Each hold is served by three hatches, the hatches being 15 ft: 3 in.:= wide and 40 ft: Jong. [he under deck lumber capacity of the ves- sel is approximately 1,500,000 ft. board measure. The central trunk is 3 ff. 6 im. wide and extends from the floor to the main deck in the design shown with this article, Tt is built 'of 125 tb: plates and 314 x 314 and 5° x 5+. 'angles. This trunk contains six fuel tanks, three high tanks and three low tanks. The capacities of the tanks are approx- imately as follows, taking the weight of fuel oil at 59 Ib) pér cue th: igh tank Nola... 2,670 cu. ft. or 78.6 tons High tank No. 2.......2,170 cu. ft. or 64.0 tons High tank No. 3......+.2,415 cu. ft. or 71.2 tons Low. tank NO. dows 2,290 cu. ft. or 67.5 tons ow stank «NO. 20s. ss: 2,220 cu. ft. or 65.5 tons Low tank No: 3.7... 2,475 cu. ft. or 73.0 tons Total tons ballast in central trunk.419.8 tons UP FLYING BRIDGE | in i fu aN FORECASTLE SG STLTITIA OU: FUEL__--) __... HIGH TANK Low ran ou FUEL | | Sanssop Pit oe if '| ta ri. '4 UNK DeEsIGNED By Epwarp S. HouGcu, SAN FRANCISCO,