LUCIA FOR THE UNITED STATES SHIPPING BOARD. 43 



Boxing in machine and engine-room 150 



Boxing for cargo 3,000 



Frame filling 450 



Dunnage for cargo boxing 160 



14,180 



Reserve buoyancy 1,140 



Average reserve freeboard 33" 



From the foregoing it is apparent that a liberal margin of reserve buoyancy 

 can be obtained, at the same time retaining 86 per cent of the ship's former cargo- 

 carrying capacity. 



DESCRIPTION OF DRAWINGS. 



Plate 23 gives a typical cross-section of the ship and the general arrangement 

 of the boxing located along the sides under the three decks, and on both sides of the 

 transverse bulkheads. This drawing also shows the draught lines under various con- 

 ditions of loadings. 



Plate 24 gives details of the various framing construction and fittings necessary 

 to secure the boxes in place. As far as possible a standard size of lumber has been 

 used throughout the ship for this work. 



Plates 25 and 26 give details of the three types of boxes found necessary. The 

 boxes have been so standardized that a uniform size of lumber can be used for all 

 types. 



Plate 27 gives a general layout of the ship, showing space occupied by the box- 

 ing and space available for coal cargo. This drawing also shows a longitudinal sec- 

 tion of the ship, giving the various transverse bulkheads and decks. 



From the plan as outlined by the figures and drawings above referred to, it will 

 be perfectly plain to engineers, but the carrying of it out for the first time under war 

 conditions was found to be anything but a simple matter. The only material avail- 

 able immediately for creating the buoyancy boxes was ordinary lumber and galvan- 

 ized iron, and the quantity of sheet metal required was rather a surprise to local 

 markets. 



It was soon found that ordinary methods of construction would not do, and care- 

 ful experiments were necessary to develop the details of construction for the boxes 

 as set forward in the plan. 



A testing plant capable of testing the dififerent sizes and types of boxes to de- 

 struction by outside water pressure was created and, as might be expected, had to be 

 completely rebuilt before satisfactory results could be obtained. 



After the type of box and entire construction for withstanding pressure had 

 been developed, many difficulties were met with before absolutely watertight results 

 could be obtained, and these results were finally maintained only by testing every box 

 by air pressure and floated in a tank before placing it in the vessel. 



