188 MACHINERY AND TRIALS OF THE PASSENGER SHIPS 
Bilge keels are fitted at the turn of the bilge and extend along the ship for a distance 
of 190 feet. They are 15 inches deep with double angles at the shell and stiffened at outer 
edge with a half oval. 
The vessels of this size and type were constructed in three different shipyards, two by 
the Newport News Shipbuilding and Dry Dack Co., nine by the New York Shipbuilding 
Corporation, and five by the Bethlehem Shipbuilding Corporation, Ltd., at the Sparrow’s 
Point Plant. The machinery, therefore, while having the same general features, varies con- 
siderably in detail. The Hawkeye State, now the President Pierce, built at Sparrow’s Point, 
is the vessel which was run through the standardization trials, and it is the machinery of this 
ship which is briefly described in the paper. 
The engines are designed for 12,000 shaft horse-power on two shafts, and each shaft 
is driven by compound turbines through single-reduction gear. The turbines are of the Curtis 
type, and each high-pressure unit consists of twelve impulse stages. The first stage has a 
single wheel with two rows of l-inch blading on a 36-inch diameter pitch circle. The res 
maining eleven stages each consist of one wheel with a single row of 34-inch blading. The 
pitch circle diameter of these wheels varies from 3414 inches in the second stage to 36%4 
inches in the twelfth stage. The diaphragms between the wheels are of cast iron with nickel 
steel nozzle plates cast in and extend from the casing down to the hub of the wheels, where 
they are sealed by serrated brass packing. 
The low-pressure turbines have seven stages, each stage consisting of a single wheel 
with a single row of 1-inch blading, and the pitch circle diameters vary from 49% inches 
in the first stage to 54 inches in the seventh stage. The diaphragms are of similar construc- 
tion to high pressure. 
The astern turbine is located at one end of the low-pressure turbine and consists of two 
stages, each stage having a single wheel with two rows of 1-inch blading, and the pitch circle 
diameter is 363@ inches for the first stage and 391% inches for the second stage. 
These turbines were built by the Fore River Plant of the Bethlehem Shipbuilding Cor- 
poration, Ltd. 
The first stage nozzles of both ahead and astern turbines are machined and carefully 
reamed to gauge. The first stage ahead has eight open nozzles—that is, only controlled by 
the main throttle valve—and two sets of three nozzles, each set controlled by an individual 
valve so that the power can be varied from 7,000 to 13,000 shaft horse-power in three stages 
so as to get the greatest advantage of full boiler pressure. One peculiar feature of these tur- 
bines is that the blading is all of the same hand, the right and left-hand rotation being ob- 
tained by turning one set of turbines end for end. When going ahead the steam flows aft 
through the port turbines and forward through the starboard turbines. 
The reduction gears, built by the Falk Company, are of simple construction and of 
ample proportions. They are single-reduction gears with two pinions and main gear wheel 
in a single plane. The pinions are 9.143 inches in diameter at the pitch circle with 32 teeth, 
and the wheels are 131.143 inches in diameter at the pitch circle with 459 teeth. The width 
of the working face is 36 inches. The pinions are made of. chrome vanadium steel, heat 
treated, and the main gear wheel is of cast steel in one piece with the teeth cut-in the rim. 
These gears have given excellent service so far and show every indication of having a long 
life. The main thrust, which is of the Kingsbury type, is incorporated in the forward end of 
the gear casing and is 25 inches in diameter. 
The line shafts are solid mild steel, 1534 inches in diameter with solid couplings and are 
raised to 16 inches diameter for the bearings. The propeller shafts and stern tube shafts 
