The severity of the Russian winter, with its heavy snowfalls, creates serious transportation
problems. This is particularly true in northern Russia, where lack of roads formerly made
dog- or reindeer-drawn sleds necessary for transport. Soviet technical skill and ingenuity, however, have
successfully coped with the problem by developing mechanized sleds, which have good traction
both on hard-packed snow and soft new snow.
The most satisfactory and efficient type of mechanized sled for winter transport has been found
to be the aero-sled, powered by an airplane-type engine and mounted on either three or four skis.
The accompanying sketch shows a general view of the Soviet NKL-16 aero-sled with
an M-11 motor. All accepted types of aero-sleds have a closed streamlined cabin (1) which
transports six to eight persons plus freight, depending on the horsepower of the motor and
design of the sled. The cabin is mounted on shock absorbers (2), which are connected to
the three (or four) skis. The motor (4) is generally mounted in the rear with the
pusher-type propeller (3) and a guard (6). The skis are connected to the body also
by means of universal-joint semiaxles (7) and "unloading" connecting rods (8).
This three-rod type of mounting of the skis insures proper shock absorption and fixes the
skis rigidly in relation to the body of the sled. A turn of the steering wheel (9) causes
the front ski to turn. In the four-ski-type aero-sleds of the latest design, the two rear
skis glide in the tracks made by the front skis. The brakes are applied by pressure on a
foot pedal which causes 1 to 1 1/2-inch metal rods to protrude from the bottom of the
skis and engage in the snow. An air-cooled motor in aero-sleds eliminates radiator and
water complications in the cylinder sleeves and lends to light design.
The following discussion of various aspects of the problem of transport operations
by aero-sled is taken from a recent issue of a Soviet trade magazine.
"Aero-sleds must satisfy certain technical requirements. For example, the supporting
surface of the skis must completely safeguard the sled from falling through the snow
or getting stuck in it. Experience in the U.S.S.R has proved that the load weight of
the sled while in movement must not exceed 1,200 to 1,350 pounds per square yard of
supporting surface. The total weight of the loaded sled must not exceed 33 pounds per engine horsepower.
"Other essentials include durability of construction, using inexpensive, plentiful materials. The
driver and crew must be protected from headwinds and must be able to observe the road to the front
and on both sides. Brakes are needed to assure safe descent on steep inclines, especially on slippery
and rolled roads. The propeller must be equipped with some form of guard to prevent accidents.
"It may be said that the essential qualities of aero-sleds are: simplicity of manufacture, low
cost, ease of repair, and good driving power.
"The improvement of travel qualities of aero-sleds can be accomplished by: reducing the weight of
the sled by lighter construction, reducing the load capacity (a serious disadvantage), or increasing
the traction power of the propeller. The latter may be accomplished by improving the design of
the propeller or using a motor of greater power. It may be considered that the present models
of aero-sleds yield roughly a power effort of the propeller equivalent to 6 to 6.5 pounds per
"Although the average speed in actual work is lower, it is possible to drive aero-sleds at a
speed of 20 to 30 mph, depending on the snow surface and the experience of the driver.
"As the Soviet Union lacks winter roads, the opportunities for using aero-sled transportation
are very numerous. For that reason, in spite of the favorable achievements in design and efficiency
for use over even rough snow and ice, many improvements can yet be made. A switch to the use of
heavier fuel, as well as to simple and inexpensive motors and steel propeller should
be combined with further perfection of body design and of moving parts."
On the basis of sketches of aero-sleds which have appeared recently in the Soviet press, it
seems probable that the Russians are employing aero-sleds as combat vehicles, both as a
reconnaissance car mounting a heavy machine gun, and as an armored fighting vehicle with
a sizable-caliber gun mounted in a revolving turret. No details, however, are available
on this aspect of the employment of aero-sleds.