42 APPLICATION OF BUOYANCY BOXES TO THE STEAMSHIP 



"The buoyancy of a metal boat shall be not less than that required above for a 

 wooden boat of the same cubic capacity, the volume of the air cases and external 

 buoyancy being increased accordingly." 



The discussion of the application of internal buoyancy boxes before the com- 

 mittee and Naval Advisory Board found a unanimous opinion that something along 

 these lines should be undertaken immediately. 



The writer, on behalf of the committee, prepared preliminary plans and calcu- 

 lations and investigated the vessels available. This resulted in the selection of the 

 former Austrian steamship Lucia of the following general dimensions and ton- 

 nage: — Length, 418 feet; beam, 54 feet; depth, 37 feet; gross register, 6,744 tons; 

 net register, 4,386 tons; coal bunker capacity, 620 tons; water ballast, 1,583 tons; 

 dead weight capacity all told, 9,600 tons; summer draught, 28 feet ii>4 inches. 



The Lucia was a modern steel freighter, built in Trieste, Austria, in 1912 and 

 equipped with English machinery. 



At about the time referred to, the early part of 19 17, the shortage of coal in the 

 Mediterranean had reached such a degree that $100.00 a ton freight was being 

 offered, without avail, for ships to carry coal to Italy. In view of this, it was decided 

 to fit out the Lucia so that she could carry coal when water-logged. 



A simple statement of this problem is as follows: — 



Weights to be Supported. 



, Tons. 



Weight of coal 8,200 



Coal consumed 600 



Net weight of coal 7,600 



Weight of ship 4,100 



Weight of boxing 1,000 



Weight of frame filling 250 



Weight of dunnage for cargo boxing 90 



13.040 

 Displacements or Buoyancy. 



Tons. 



Coal displacement (specific gravity 1.36) 5^3^ 



Displacement of fittings of hull 400 



Steel and machine displacement 520 



Double bottom and peaks 1,600 



Propeller tunnel 300 



Side boxing, 150 lbs. per foot run 7,860 x 150 lbs. 



Bilge boxing, 200 lbs. per foot run 808 x 200 lbs. 



Deck boxing, 150 lbs. per foot run 4,060 x 150 lbs. 



Deck boxing, 150 lbs. per foot run 4,060 x 150 lbs. 



Deck boxing, 200 lbs. per foot run 4,060 x 200 lbs. 



Bulkhead boxing, 200 lbs. per foot run 5,270 x 200 lbs. 



1,970 



