Imperial Valley press., 1924-10-23

dependabilitv of an airship's motors
largely rests the biggest factor of
safety for the ship. To obtain the
most dependable motor efforts were
made to design the most simple
motor possible.
The simplicity of the Shcnan-
doah s engines was demonstrated
stBikinglv when the ship had her
successful fight with the gale Of
last January. Because the regular
engineers were at dinner in their
quarters when the accident occurred
there were only three men on hoard
who were familiar with the engines.
Inexperienced men started the mo-
tors without a second s delay, which
might have been fatal 10 The ship
and the % men aboard her. The
same inexperienced men kept ,hem
running without e miss during the
whole fight against the elements
until the ship was safe in her lang
ar.
Economy Was Essired
Reliability, durability, economy
and light weight were the char
acteristies desired in the order Civ
en- when the bureau of aeronadtics
prepared set of specifications Tor
an ideal motor FOX the Shenan loah.
Economy was desired above weight
as the weight of the fuel to be
carried was to be nearly four times
the weight of the engines and the
specifications provided that every
possible effort should be made to
obtain the last ounce of power from
the fuel.
The net result of this provision
was that in 300-hour endurance
test Of the engine a world s "eeord
for economy was obtained. Less
than .45 pounds of fuel per brake
horse power were consumed. On
the first long flight taken by ahe
ship when distance of 600 miles
was covered 600 gallons of gasoline
were consumed, making one mile to
the gallons. In terms of the family
! automobile one mile TO the gallon
of gasoline is anything but econo-
nv but, despite her tremendous size,
one mile 10 the gallon repres ants
with the Shenandoah "a greater eco
lnomy per passenger carried than
that shown by any automobile.
On cross country trips wherever
the Shenandoah lands she is hand
led by a ground crew of more than
two hundred men. The technique
of landing the ship has been highly
developed by the naval officers who
handle her. +;
The ground crew is spread out in /
a big letter "U' with the closed i
end of the lines toward the direc- !
tion from which the wind is blow
ing, Giant signal boards give the !
navigators the force of the wind, |
its direction, barometer readings
and the temperature of the air and
of the ground. Other signal de
vices permit the crew to "talk'
with the officers in charge of the
landing crew.
When the ships barometer has
been corrected by the land baro-
meter and temperatures in the air
have been compared with tempera-
lures at the ground to insure against
any mistake in determining altitude
or in bringing the ship to the prop
er equilibrium in the warmer ground
air /the elevating rudders turn her
nose toward earth. The engines
drive the ship down against the.
lifting pressure of the helium gas.
Only when such action is absolutely
necessary is any of the helium re-
leased, because of its great cost.
Big Ropes Released
As the bow is driven down tow
ard the earth, two big ropes are
released through trap doors on the
under side of the hull. These are
seized by the crew assigned to that
task. The bow is held down, and
is forced down until ropes all along
the engines driving ahead, the tail
the under side of the ship can be
grasped by other details of men.
When leaving the ground the ship
first is "weighed off" which con