Evening star., 1915-11-14

by the rapidlty in advance displayed
by the Germans in certain recent ac-
tions there is not very much wrong
with their military motor transport
system.
IN the army transportation service
in the European war, at least on the
western front, there are two different
phas on good roads
up to within a few miles of the firing
line and transportation on bad roads In
the territory traversed several times
by the opposing armies and more or
less badly rutted by thousands of vehi-
cles and possibly damaged by artillery
fire. There is also a fair amount OF
transportation across fields and open
country to the firing line. The first
kind of transportation. over good
the haulage in the commercial world
in times of peace: so this phase of the
subject can be dismissed.
Troubles Due to Bad Roads.
TT is on the bad roads. damaged by
heavy vehicles of all kinds and some-
times by shell fire, that most of the
troubles of motor trucks in the war
have occurred. Vehicles of English
manufacture, which on the beautiful
roads and boulevards Of London aver
aged anywhere from 10000 to $4,000
miles on their original tires. have need
ed new tires after from 1000 to 1000
miles of travel near the army depots
near the front.
"A type of motor truck peculiarly
fitted to the operating conditions that
arise in active army service has been
developed in America. The truck re-
ferred to drives, brakes and steers on
all four wheels. Its ground clearance
traction of the fourwheel-drive is well
known. The truck with power applied
at all four wheels can climb grades
and pull through mud. sand or snow
truck. Obviously truck with brakes
on all four wheels can be brought to
a standstill more easily than one which
brakes on only two wheels. A truck
with both front and rear wheel steer
ing can turn in half the distance re-
type
Another feature of the truck is the
automatic locking differentials which
put the power into any wheel or wheels
cannot. These differentials, of which
there are two, one in the front power
axle and one in the rear, have spiral
gears that are irreyersible. The action
in such that none of the road wheels of
the truck can lag in speed behind the
motor The two outermost wheels can
overrun the others in turning a corner,
but as soon as any wheel tends to lag
behind the motor, the differential locks
automatically and the driving shaft is
virtually solid from wheel to wheel
If one wheel does not get traction and
the other does. the latter Immediately
takes all the power that previously
was shared between the two wheels,
and as long as 1t can get traction it
Will pull the vehicle out of the hole,
provided the motor has the power to
move the truck at all.
Location of the Motor.
The motor is situated partly under
the f1oor-boards and partly under a
hood in front of the driver, to the
right. The motor drives through a
dry-disk clutch and longitudinal
shaft to four-speed Transmission
situated about the middle of the
chassis. This four-speed transmission
Is OF the selective type with the for
ward speed gears constantly in mesh.
ne speed changing is effected by dog
erorches. er e broad silent chain drives
from the intermediate spindle of the
transmission to shaft which runs
right through the transmission, so that
power can be taken from both ends.
AT each end of this shaft is connected
propeller shaft with universal
joints at each end), which drives the
power axle through a pair of beyeI
gears and the differential that has al
ready been mentioned. Each differen-
tlal casing is bolted firmly to its re-
.ne vehicle Is supported on two dead
axles. and not carried, even in part.
BY the power axles.
me hnal drive is by internal gear
IN each OF the four wheels. The power
axles. which emerge one from each end
OF the differential, connect through. a
UNIVERSAL tball and socket joint with
pinion that meshes with an internal
gear nxed firmly In an opening ON the
,nsioe hnn race OF the road wheel. The
pail and socket connection between the
power axle and the driving pinton in
each wheel permits the wheel to be
turned at an angle to the live and dead
axles.
"All through the machine. wh.r.ver
IT is possible. standardized details
have been used. The result is that
fewer different parts enter into the
construction. Notwithstanding the APP
parent compiexity involved In the
four-wheel drive, brake and steer fea-
lures.
1T will be interesting to compare
the leading dimensions of the truck
under discussion with those of the
trucks that before the war were ac-
cepted under the French army sub
sidy plan. and which during the war
have proved out so successfully The
average French army truck motor has
ss-inch bore and 5.7-ineh stroke, as
O.$C n.
The average speed Of the French
motors is 1.132 revolutions per minute.
as against 1.1l2. The average French
truck tires are aes inch by 80 inch
front and 3s.1 inch by as inch rear, as
compared with 36 inch by inch front
and rear. The water-cooling system IL
by centrifugal pump and the lubrica-
tion force feed and splash system, both
of which are the prevailing practice In
the French army trucks. Many other
similarities could be noted.
Reversible Four-Wheel Drive Truck.
The reversible type Of four-wheel-
drive truck is important from the army
standpoint. This machine can be driven
from either end and has four speeds
forward and four REVERSE It was de-
signed for carrying q machine gun
mounted In a revolving turret. The
truck can run up to the enemy's trench
and. II necessary, retreat without hav-
ing to turn around. This 10 a great
advantage under any circumstances,
and especially SO on narrow country
lanes. Such truck can turn in q circle
of from IS to SO feet diameter.
which is about one-haf the space re-