THE PROPELLING MACHINERY OF THE U. S. S. LEVIATHAN. 



223 



of the barrel, the pedestals which support the bearings, etc., being bolted to the cas- 

 ing and arranged so that they can slide in the aft direction. 



The diameter of the rotor drum is about lo feet lo inches, and it is made up 

 in two sections bolted together. The disc ends are bolted to internal flanges ar- 

 ranged at each end of the drum. 



The dummy at the steam inlet belt is of the radial fin type and the overall length 

 of the drum is about ii feet (Fig. 7, Plate 98). 



There are thirty-seven rows of impulse-reaction blades in casing and rotor, ar- 

 ranged in five expansion stages, with blade heights varying from 6-^^ inches to 13^ 

 inches in length. 



The steam is admitted to the aft end of the casing through a nozzle about 29 

 inches diameter. 



The area of the exhaust branch to the condensers is about 50 square feet. This 

 branch is built up of steel plates and flanges in five sections of rectangular shape, 

 and forms a large arch from the exhaust end of this astern casing over to the niain 

 exhaust trunk (Fig. 8, Plate 98). 



Main Bearings. — The lower half of the rotor bearing shells are made of com- 

 position, and the design is such that cold sea-water circulates in a jacket through 

 the casting. The surface of the bearing bush in contact with the rotor journal is 

 faced with white metal. 



Safety strips are also provided for, so that the blading will not be damaged 

 if the white metal face is melted out. 



The dimensions of the rotor bearings are as follows: — 



The safety strip is arranged at the center of the bearing shell where the lu- 

 bricating oil is admitted under pressure ; grooves for oil are cut in the white metal 

 surface, and in addition four semicircular grooves have been cut on the rotor jour- 

 nals, these being about ^-inch wide and extending for almost the whole length of 

 the bearing. 



Turbine Glands. — The glands have the usual steam supply and leak-off con- 

 nections and take the regular form of alternate rows of brass fin strips on rotor 

 shaft and gland casing sleeve. At the outer end of each is fitted four Ramsbottom 

 split rings of composition. 



