New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1916-03-12
Overlooking IS
TRUCK SUICIDE
Analysis of Damage from
Carrying Loads Over
Makers Limit.

Probably the most serious problem
confronting the manufacturers Of com
mercial motor vehicles to-day IS that
Of educating the motor truck owner
or operator against the overlooking of
his vehicle. At recent meeting OF the
Motor Truck Club OF New Jersey, the
members Of which are all users of mo-
tor trucks. Joseph Husson, Of the edi-
tcrial staff Of 1.-THE Commercial Nehi--
Gle delivered an address on overload
ng in which he pointed out the damage
and expense resulting from this prac-
tice. Mr.. Husson's talk was on "Why
Overlooking ls Motor-Truck Suicide
End in part was as follows:
"Overloading is one Of the surest
forms Of truck suicide. OF course.
there are others. such as overspeeding
and lack of care due to Inc erroneous
belief that because IL is made of metal
instead Of flesh a motor truck has none
Of the characteristics of the camel Of
old whose back was broken by the ad-
dtion OF a straw 10 its already heavy
load.
"Overloading affects every part Of
the truck. II affects the frame. springs,
wheels. axles. tires. power plant and
driving mechanism. II affects the
frame because II was designed by en-
ginners 20 carry a certain weight in a
certain position. True, the frame and
practically every other part OF the mod
ern motor truck is designed with Ger
tain factor Of safety or reserve
strength. like the columns in a building
or the girders of bridge. This re-
serve strength. however, is for emer-
gencies, not for every -hour-of the day
use.
Limit TO Frames Capacity.
Exactly the same as that which
takes place in the tissues of horse
takes place in the steel Of the motor
truck frame. The fatigue of steel is
much slower than that of flesh tissues,
but il is there Just the same. The
frame of motor truck ia designed as
q beam to carry certain specified load,
Just as girder of railroad bridge Is
designed to carry certain number OF
locomotives and coaches.
THE molecules of steel forming the
beam in each case move IN relation 10
one another when the loads are APP
piled. OF course. you cannot see the
movements of these molecules with the
naked eye, but science has proven that
they do move. When the loads applied
are not greater than those for which
the beams were designed. the molecules
tend TO move back TO their original po-
sitions after the loads have been re-
moved. But if the loads are greater
than those for which the beams were
designed, these molecules cannot re-
turn TO their original positions. and the
beam assumes set or bend and does
not return TO its original position
afterward.
The Elastic Limit.
"The steel in this case is said TO have
reached its elastic limit, or that load al
which the beam will not return 10 It's
original position after the load has
been removed. This is exactly what
happens when the frame of motor
truck is overloaded. II assumes per-
manent set. Just as II is harder ana
harder for the flesh tissues of horse
TO recuperate after each overload
period. so the steel of the truck frame
is less able 10 withstand overloads
after II has once assumed Pc manent
set.
SUBSEQUENT continued overlooking
tends TO pull the steel molecules apart.
This results in fracture OF the
frame. and a truck with a cracked
frame is a makeshift at the best. even
If repaired at considerable cost be
cause the life of the steel IS gone. Inc
frame does not respond TO the loads
carried and IS liable 10 crack IN other
places. The cheapest way out OF the
difficulty is 10 buy new frame or
frame members. and this cannot be had
for a song. so that overlooking is de-
cidedly expensive on the frame
Geared for the Load.
Besides injuring the frame. springs,
wheels and tires. overlooking also
places a greater strain on the motor
and the remainder of the power plant
than that for which II was intended
II is true that the average motor truck
engine can develop more power than 10
normally needs to move the specined
load. II is also true that several manu- .
facturers use the same motor IN al OF
their chassis. in one case ranging from
, TO 6 tons capacity. Ia the latter IN
stance. however, the final gear reduc
ton from the motor 20 the rear Whe'lS
in high gear is increased from one rev
olution of the rear wheels TO SIX OF the
motor on the two-tonner 10 one reVoiu-
ton TO ten and one-half in the six
tonner. The power produced by the
motor in each case is the same.
power is the rate Of work. Work IS
tho sustained eXertion OF pressure
through space. With the given gear
reduction the two-tonncr carries rs
load in high speed az the rate or saw
fourteen miles per hour. whereas the
six-tonner carries its load at the rate
OF about ten miles and hour. The same
amount Of work has been done in each
case. but the rate OF work has been
varied from moving a relatively light
load quickly to heavy load slowly.
Excessive Wear.
when a truck is overloaded The