The Bridgeport evening farmer. [volume] (Bridgeport, Conn.) 1866-1917, 1915-12-07
HOW SPEED AND
HILLS TAX CARS
Chronic Speeder Must Bear in
Mind He Is Putting His
Auto to Severe Trials

Most of US know the motor1st who,
| imagining himself a miniature Resta
or Oldfield, will tear through the
town with a wide-open throttle, in
gleefuI realization of the fact that his
| machine, by being pushed to the very
| limit of it's capabilities, will attain, and
maintain speed of mile minute,
or even more.
! 1t is to the everlasting credit Of the
automobile that these Civilizations of
speed may be continued with COM
parat1Ve impunity for a considerable
time. However, he who is familiar
with railroad mechanics and knows
the intervals within which the average
! locomotive goes to the round-house
for repairs understands that though
| the locomotive travels on an ideal
road surface which is not interrupted
by the slightest inequality, every de-,
mand upon the engine beyond the
normal service conditions for which
| it was designated must result in alb
| normal wear and tear.
/ The point is not often made, but is
worthy of attention, that for purposes
of transportation it is impossible to
consider the motor vehicle apart from
the road on which it travels; the one
is as necessary as the other.~And, ul-
tin1ateIy, the mechanism of an auto
mobile rests not on the brick founda-
= tons of stationary engine, nor on
the ideally conditioned steel rails of
the railroad, but on the ordinary road
surface which changes during every
second of running. True the modern
automobile acquits itself nobly of it's
tasks, when used sensibly. But the
chronic speeder, who is apt to be dis
grunt1ed at what to him may seem
| unreasonaba1e wear and tear, must
bear in mind that he is putting his
car to severe trials every time he
races it over the ever-changing road
surface with every ounce of reserve
power in action.
Similar observations may be in or
der in regard to hi1l-clinbi bling. The
persistent high-speed hi11-climbing is
first cousin to the scoFcher. Climb
ing every hill on the high gear, while
it may be done, imposes the hardest
kind of work not only the motor
but on every other part of the car.
| The lower gear ratios are provided
for hilI-climbing, and they should he
: used for it. 1t may be. we'll to con
slider a. little more carefully the
: amount of work done by automo-
= bile climbing a gradient on, say, a
e gear ratio of three to one. This means
that one revolution of the driving
! wheel is produced by three revo1u-
: lions of the engine crankshaft. With
. the other gear ratios. the intermediate
and the low, the number of revo1u-
: tons Of the engine become still great
| er as compared with the number OF
Y driving wheel revolutions.
It is not difficult to compute with
exactness the distance which a, car is
T propelled by one explosion of the
engine, and the power consumed in
0 hi11-chn1bing. The circumference OF
i a thirty-two-inch wheel is approx
o mately 100 inches, and in covering
q one mile the driving wheel revolves
n | 632 times. Since the motor turns
: over three times as fast as the driving
:. | wheel, will require 1899 revolution
9 of the crank-shaft to prope1 the cal
one mile. Thus, if, for instance, {
= touring car should proceed at the
. rate of thirty miles per hour, approx
= mate1y $50 engine revolutions are re
- quired. s With two power strokes fol
/ each revolution there are 1900 expIo-
Z sions a minute, or $500 explosions
per mile, and each explosion propel
the car about one foot and four and
a half inches
: This estimate presumes that the cal
is propelled oyer level ground. TX
mount a hill means simply that grade
u resistance is added toN the various fric
. tiona1 and other resistances. n auto
$ mobile weighing 2, 100 pounds, includ
e ing gaso1ene, oil and water, climbing
. a hill 200 feet high, measured VERT
9 cally), simply performs the task O
overcoming the action of gravity, o.
: lifting, and the calculation of tn
9 power required to do this must in
n vo1ve the factors from which the
9 horsepower unit is derived! ToS 1if
100 pounds 200 feet high IN on
7 minute is the same thing as lifting
: q, 1OOx2OO-42O,O 900 pounds one foo
: high in one minute. Theoretica1l
. then, the lifting of 2,1O0 pounds 20
d feet high requires 42o,0 divided b
t33,0OO-12.75 horsepower, and tn
losses through friction air resistance
etc, consume the remainder of tn
= theoretical horsepower output.
From the foregoing it must becom
apparent that rushing up steel
= hill on the high gear must subject an
= car to enormous stresses, which ar
: likely to affect the life and the ser
= vice to a considerable extent Gear
e shifting is not a cumbersome tasl
and the mounting of gradients vii
Q not be attended by harm, if the gear
S are put to the use for which the,
= were intended.
e F'orty-three officers and electrician
# from United States navy yards ar
q being taught at west orange, N: j
l. ET-E-a .