22 METHOD OF CONSTRUCTION OF CONCRETE SHIPS. 



coats was to neutralize the alkali and harden the surface. This treatment was nec- 

 essary where it was intended to apply an oil or varnish paint. It was found, how- 

 ever, that the varnish paints were of uncertain durability on the exterior surface 

 of the hull, and a bituminous paint was substituted which obviated the necessity for 

 the application of the magnesium fluosilicate solution. In the case of one hull a 

 rapid oxidizing vegetable oil known as "Repello" was substituted for the magnesium 

 fluosilicate. This material not only neutralizes the alkali but considerably reduces 

 the absorption of the concrete. 



The following combination of coatings has been applied to the outside surface 

 below the light draught line — either two coats of magnesium fluosilicate, two coats 

 of spar varnish and one coat of anti-fouling paint or three coats of bituminous paint 

 and one coat of Mclnnes anti-fouling paint. 



The outside surface above the light draught line is covered with the same coat- 

 ings as the surface below the light draught line except that the anti-fouling coat is 

 omitted, and where the two coats of spar varnish have been applied it is followed by 

 a third coat of grey enamel. 



The weather deck is covered with an asphalt mastic % to ^ inch thick, which 

 acts as a wearing surface and will prevent leakage through cracks if any occur. 



The interior surfaces of all oil compartments are covered with two coats of 

 magnesium fluosilicate and three coats of spar varnish. In some cases a grey 

 enamel is substituted for the third coat of varnish. Cheese cloth is placed as re- 

 inforcement between the layers of varnish on the oil-exposed surface of all bulk- 

 heads which are exposed to oil on one side only. Cheese cloth is also placed in a 

 similar manner on the inside surface of the shell of the hull between frames in the 

 oil compartments. 



The interior of all water tanks are covered with either three or four coats of 

 bituminous paint. 



The interior of cargo holds and boiler and engine-room compartments are coated 

 with either one or two coats of magnesium fluosilicate and three coats of spar var- 

 nish; or two coats of magnesium fluosilicate, two coats of spar varnish, and one 

 coat of grey enamel ; or three coats of bitumen. 



OUTFITTING. 



After the concrete hull has been launched, the task of installing the machinery 

 and piping, erecting the cargo-handling apparatus and rigging, and fitting up the 

 accommodations for the officers and crew still remains before the ship is ready 

 for sea. These items are all included under the heading of "Outfitting." 



At the yards in Mobile, Oakland and San Diego, the superintendent who con- 

 structed the hull for the corporation is also doing the outfitting, and from these 

 yards the ships are to be turned over ready for service. The ships built at Wil- 

 mington and Jacksonvile are surrendered after launching to the Jacksonville Ship 

 Outfitting yard at Jacksonville, Fla. 



The first of the three items mentioned, the installation of machinery, is the most 



