Evening star. [volume] (Washington, D.C.) 1854-1972, 1926-01-17
AUTO MAKERS TEST
CARS THOROUGHLY
Proving Grounds Present
All Difficulties Met by
Tourist Travel.

Automobile makers are making {
greater effort to put value and utility
into their product by actual tests thar
any other line of industry This Is
the conviction of O. T. Kreusser OF
the General Motors Corporation eX
pressed in the January number OF
the journal of the Society of Auto
motive Engineers. in which he de
scribes the corporations new proving
grounds, where cars are submitted &c
oil kinds of tests
The proving grounds comprise ! .125
acres of private property located
within easy driving distance of the
corporations several automobile and
truck plants and engineering depart
nents. A large part of the tract Is
fat land adjacent to a hill section
that rises more than $50 feet above
the loWland. A speed track. mostly
Of tarvia paving and nearly four
miles long by 20 feet wide and banked
on the turns for a speed of 50 miles an
hour has been constructed on the
level land. where there is also a is
mile concrete straightaway that is
perfectly level, with graveled loops at
either end. At one end of the straight
away is a concrete road 200 feet .@lg.
having parapets to permit of flooding
a 100-foot section to a depth of feet.
Permanent Organization.
In the htlly section are three con-
crete roads with continuous grades
starting from level ground and in
creasing to 2I10, 9 92/100 and II 6/10
per cent Continuing from these
roads and winding through the billy
section is an endurance hill road hav-
ing gradients as steep as "a per cent.
A permanent organization of so per-
sons. headed by the director, controls
the maintenance and activities of the
proving grounds. The operations in
cIude endurance tests and observation
of the operation of experimental cars
by each automobile and truck division
of the corporation. The straightaway
road is used exclusively for making
engineering tests. such as accelera-
ton. braling, rolling friction, smooth
riding, and fuel economy at different
speeds. The underwater road is for
determining how wet ones feet be-
come in closed cars when driving in
puddled roads and for putting brakes
In condition for braking tests under
rainy weather conditions.
Some idea of the extent of the
analytical endurance tests Is afforded
by the fact that the car mileage made
on the proving grounds roads runs
we'll over 200,O miles a month and is
SLedullS llCISdSlIS.
Special Devices.
Many special instruments are used
for obtaining accurate records of per-
Torrance. Speed is recorded by a
speedometer carried on a fifth wheel
that is clamped to the running board.
Acceleration is indicated by an cleo
trio accelerometer that punctures
holes in a paper tape at 1-foot and To-
foot intervals of car movement and
at half-second time intervals. Deceler-
alton, or braking, is measured by an
instrument that records the rate of
stopping and also the amount of foot
pressure on the brake pedal. Steering
effort and clutch pedal pressures are
also measured, and vibration Is re-
. corded electrically. Obstruction of
tparts of the car to the drivers vision
lis determined by means OF wall
marked off into squares with chalk
lines, and angles of reflection from the
windows and windshield are measured
by placing the car in the center Of a
circle 100 feet in diameter and carry
ing a light around the circumference
OF the circle, which is staked off in
degrees.
AS most Of the test traffic comes on
about five miles of road, including
the test loop and the concrete test
l.ills, and there is a traffic density of
about one car per minute for the "a
hour day on the hard surfaced roads,
the proving grounds are affording a
good test of road durability as we'll as
car performance and endurance.