The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1898-12-25
BoTTLING THE AIR.

! In the air power plant now building
| at West Twenty fourth street and
Eleventh avenue. New York, the power
is developed by what is described as a
! three-Stage compressor. N the first
( chamber the air is driven I'D to a Ires-
sure of about 100 pounds to the square
J inch. It is then cooled by a " alter
jacket. and enters a second cylinder,
where the pressure is increased. The
| cooling process is repeated, and the air
passes to the third chamber, where it
is driven UP to, the pressure OF $500
lpounds to the square inch. at which
/ 1t is to be used. For the third time
the air is subjected to The cooling and
| drying process, after which it is cc1-
veyed to a series of connected Names
mann steel TASKS, where it is stored
awaiting use. The purpose of the
water jackets is to do away with the
heat, which naturally ACCOMPANIES the
compression.
Each OF the air motor cars is flied
with Mannessmann steel bottle y
extending lengthWise beneath the Goor
OF the car. This bottle is q long steel
tube with a capacity Of dfty-one cubic
leet Before being placed in the car it
is tested to resisting strength Of 5000
pounds to the square inch. 81 that
there viii be no danger of breakage
under service conditions.
CHARGING THE CARS WITH AIR.
The empty cars are run up TO the
charging stand in the power house and
| connected with the main storage cham
bers. Air is admitted to The car flask
until the desired preSSure-2,0 600 pounds
is registered by the storage gauge
Then the connection is broken, the air
in the chambers being prevented from
escape by check valve, and the car is
ready for a journey Of from fifteen to
twenty miles. The whole process of
charging occupies only TWO minutes,
and in the event of haste, can be COM
pleted in less than a minute. so that it
will not cause delay, even WITH Il cen
gested traffic
While this charging process is going
on connection is established With an
other chamber beneath 5he car. and live
steam is introduced to this corpart-
ment until a temperature of 81 . degr ees
Fahrenheit is registered. This device
is one of the most important improve
ments in the development of compress
ed air traction. 1t makes possible the
relocating o fthe air before it is used,
thereby increasing its efficiency 100 per
cent, and making it possible fo% air to
compete with electricity in the item of
expense.
AS the cold air leaves the bottle he
1Sdlu the Car. II passes tilTOuSu dl
automatic valve, which reduces the
pressure from 1000 pounds 20 150. the
latter being the pressure at whi2n It is
applied to the motor. The air rasSeS
through the reducing valve to the hot
water chamber, the heat thus applied
to it causing an expansion which near
ly doubles its working power. Thai is
to say, each cubic foot of air, altar be-
ing heated. carries the air twice as far
as it could if it remained cold.
MACHINERY IS SIMPLE.
The motor mechanism consists of two
link-motion, reciprocating engines. hav-
ing cylinders seven inches IL diameter
and a 14-inch stroke. The Iower is ap-
piled by connecting and parallel rods
direct to the crank pins of the four
driving wheels. The entire weight OF
car and apparatus is mounted on clip
tic springs. which give II slnoothness
of motion not obtained in the ordinary
car. At the point where The air IS fin
ally set free, the pressure is SO slight
that there is no sound of exhaust The
only way in which the eScaD ping current
manifests itself is by little puff Of
steam, such as is caused by Cne's bl tn
on frosty morning. This, of course,
is due to the difference in temperature
between the atmosphere ami the air
operating the motor.
According to its advocates COM
pressed air possesses many points of
superiority over street traction over
any other power at present n use. Ed
ward h. Pettee, the consulting engi-
neer Of the air power company, says:
Street railway engineers have long
demanded an independent motor-one
that should make each car automobile
so that an accident at a central
no -4e,+f
up whole system. This is provided
by compressed air. and may be describ-
ed as one of its chief engineering adj
Vantages. Perhaps its greatest recon-
mendatfon from the point of view of
the public is its safety. In case of con-
troll, it eXcels any other system that I
know Of. The high pressure air is al
ways at command to set the wheels
and can be applied by a simple wrist
movement by the motorman.
1.-THE entire mechanism is simple and
does not require any special skill to
operate. The installation is much
cheaper than that required by electric
power thus effecting a saving in inter
est charges. 1t is never necessary to
tear up the streets in order to extend
the power. The cars can be run where
ever there are tracks. In all these par
ticulars I believe compressed air to be
veloped;'' r ~
Whatever advantages compressed air
possesses on the score of safety or
esthetic qualities, the point which is
likely to determine its final acceptance
or rejection by railway capitalists is
the matter of cost as compared with
other forms of power. If it costs the
railway company less for each car mile
run by compressed air than it does
with any power at present employed,
compressed air win be installed sooner
or later.
COST OF THE NEW SYSTEM.
On this point it is impossible to make
a convincing comparison, for the reason
that air has never been EMPLOYED on
a. large system. and on such 2 road the
cost of operation for each car mile is
likely to be less than on a small line
For electricity, cable, gas and animal
power approximately exact figures are
to be had. In the following table the
from figures complied in New York
and London. The figures given for air
power are computed by a conservative
engineer from the showing of the air
motor cars in their trial service:
Animal ...................... II
CaDle -. -. ...-''..... .-.......... IL
(undergrOund). .......... .12
(overhead) ,...... 10
Gas (LOndon) -. ................ IL
Compressed air ...........-....10 to u
The cost of operating the three air
power cars run in New York was 20
cents per car mile, as follows:
Coal .......... -.-..-..--.-.--.....SO O433
Water ....................... .0103