AMERICAN LEGION CLASS. 189 
are 1734 inches diameter with composition sleeves about 7 inch thick shrunk on in way of 
bearings, the latter being of lignum vitae. The line shafts are 169 feet 5 inches long from 
the coupling of the gear shaft to the center of the propeller, and each line has seven bear- 
ings 24 inches long. The bearings are lined with white metal and arranged for ring oiling. 
The screw propellers are made of bronze, and are solid, three-bladed, 16 feet 6 inches 
diameter, 17 feet pitch, and each has 80.7 square feet of developed surface and 69.4 square 
feet of projected surface. They are machined to pitch on the driving faces, balanced and 
polished. Plate 54 shows the form and gives full particulars of these wheels. 
The lubricating oil is arranged on the gravity system with two pumps, two coolers and 
one gravity tank to each engine. 
There is one V-shaped condenser to each engine with built steel shell, rolled brass tube 
plates and cast iron water ends. There are 4,405 54-inch diameter tubes, 10 feet long be- 
tween tube plates, making the cooling surface 7,200 square feet. 
A section of the bottom tubes is pocketed to form a cooling chamber over which the air 
and vapor must pass on their way to the air ejector suction. 
The turbines, condensers, condensate pumps, air ejectors and lubricating system make a 
complete unit for each shaft. 
The boiler installation consists of eight water-tube boilers of the Yarrow type, arranged 
in two boiler rooms. The total heating surface in the eight boilers is 40,000 square feet. 
The tubes are 1 inch outside diameter, 0.095 inch thick, except for the two rows next to the 
fire which are 1%4 inches outside diameter, 0.109 inch thick. Superheaters of the Foster type 
are fitted, enclosed in the tube nest so that they can be drawn into the stokehole by remov- 
ing the covering plate. The total superheating surface is 5,000 square feet, and they are lo- 
cated so that the temperature of the gases will be from 900 to 1,000° F. 
The boilers have cylindrical steam drums, 4 feet 2 inches diameter, and 12 feet 9 11/16 
inches long, which are large enough to furnish ample steam space and a reasonable amount of 
reserve water. The water drums are also cylindrical and are 2 feet 6 inches in diameter. 
The boilers are oil fired, using mechanical burners and closed stokeholes. The burners 
were originally of the navy type, but the stokeholes did not prove very comfortable and on 
the last two ships they were changed to Dahl burners, which resulted in the ships being able 
to make full power on natural draft and allowed of working under much more favorable con- 
ditions. The remaining three ships of this group will be changed accordingly. 
[The boilers installed on the passenger ships of this class, built at the New York Ship- 
building Co., are as follows: 
Numberrotuboilersroomsanser ac meee eae 2 
Number cots botlensianscticis crs wie sense keine ee ene konchate 8 
ABN cer nea ta ciai wieic b wicks w old-c Gow er Ore meee ie tein nce Cre a Water tube 
Migke so baka Nercm cater sveneneneee pista atari A atACURIE ete Babcock & Wilcox 
Workinsapresstunes (pounds))aremenarer i ori oe ciate 265 
Superheatinn cantare chen Soitre article soir aes Wibamantrs ates 75°F. 
Total heating surface (4 boilers) evaporating surface.......... 41,376 
Total superheating surface (4 boilers) ..................... 4,160 
Drak tee ieen to hee ere eae aa ae Forced, closed stokehole (1”) 
Rite lea titer canes iret cre eaters Tous i aereerararavcyie ny iaranetostapatistel sc woxtar ons Oil 
INumberotbumienrs) permbotlen. crate scabies eerie oe 7 
My pevotabunnena ia atame amitteeciere ets Sfoleay= Ouch eestor cine nents B. & W. 
