196 ELECTRIC PUMPING EQUIPMENT AND NOTES OF INTEREST ON 
only to the reduction gear turbines and location of cargo pumps and motors indi- 
cated on the profile inboard and upper deck. Tanks 1, 2 and 3 are much smaller than 
the remaining tanks and have an independent discharge line. These were intended 
for light distillates, but have not been used for that purpose up to the present time. 
The propulsion equipment was furnished by the General Electric Company and 
consists of a Curtis turbine of the type developed for ship-propulsion work, operat- 
ing at a speed of 3,500 revolutions per minute, direct-connected to a double reduc- 
tion gear suitable for reducing the speed of the turbine to 90 revolutions for driving 
the propeller (see Fig. 3, Plate 111). The normal rating of the turbine and gear is 
2,600 brake horse-power, with a steam pressure of 200 pounds at the throttle valve, 
50 degrees superheat and exhausting into a vacuum of 28% inches, measured at the 
exhaust inlet with the barometer at 30 inches. 
The steam turbine consists of a forward 5-stage element and a 2-stage re- 
versing element mounted on the same shaft and exhausting into the same chamber 
(see Figs. 4 to 6, Plates 112 to 114). Control of these turbines is effected by means 
of a throttling lever actuating balanced valves located respectively in the steam lines 
to the ahead and reverse turbines. Speed of the turbine is controlled by throttling, 
and there is also provided a hand-operated stop-valve in the reverse line which is 
normally kept closed while at sea, in order to prevent any possibility of leakage of 
steam into the reversing turbine. This valve is opened when it is desired to maneu- 
ver or make a landing. 
The ahead turbine consists of five Curtis stages as stated above, the first or 
high-pressure stage carrying two rows of buckets and the remaining stages a single 
row of buckets. The buckets for each stage are mounted on a rolled steel plate 
wheel, into the periphery of which the buckets are dovetailed in a manner developed 
by the General Electric Company and successfully used for many years to meet the 
severe requirements of central station turbines. Steam enters each stage succes- 
sively through nozzles carried in the diaphragms between each stage. 
The reversing turbine is of the same construction as the head turbine, with the 
exception that it consists of two stages only, of smaller diameter. The reversing 
turbine is capable of developing two-thirds torque and two-thirds speed with the 
same steam flow taken by the ahead turbine under normal operating conditions. 
The nozzle capacity, however, is greater than that of the ahead turbine, so that the 
requirement of reversing power may be considerably exceeded under normal op- 
erating conditions. 
The reduction gears are of the helical type and arranged to give two speed re- 
ductions, the high-speed reduction ratio being 5.03 and the low-speed reduction ratio 
7.75, making a total reduction ratio of 39.1. The high speed or driving pinion 
meshes with the two gears, one on each side, the three shafts lying in a horizontal 
plane. The low-speed pinions are mounted on the same shaft as the high-speed 
gears. The adjustment is such that work is divided equally between the two low- 
speed pinions. 
The high-speed gears are built in accordance with the “Alquist” patents and 
