TM 5-852-9/AFR 88-19, Vol. IX
snow can enter small cracks in doorways, windows, or louvers intended for ventilation. Generator intakes
are occasionally blocked, and warm exhaust stacks and vent pipes coated with ice. Large snowdrifts can
accumulate on low roofs and in other areas of "aerodynamic shade." In permafrost areas, snow infiltration
in ventilated foundations can be a serious problem. Material and equipment must not be stored adjacent to
or under buildings elevated above permafrost since that can result in snow drifts which allow soil warming
in winter. Observing site conditions gives important indicators of potential snow drifting problems, and aerial
photographs are quite valuable. Weather records should also be consulted to determine the intensity,
direction, variability, and frequency of storms and prevailing winds. At one site, prevailing winds may be
responsible for most drifting; at another, occasional storms may generate the most problems. It is not
uncommon for snowdrifts to cover doorways (see figure 1-4). Winter site visits can be very valuable.
(2) Solutions to snow drifting problems. Drifting patterns are difficult to predict but the following
guidelines will help minimize problems:
(a) Use trees, shrubs, snow fences or other obstructions to precipitate snow before it reaches
the site proper. Where storms may come from any direction, provide protection from all quadrants.
(b) Place major roads parallel to the prevailing wind direction.
(c) Do not locate roads directly upwind or downwind of large obstructions. Where possible,
maintain 100-foot upwind and 200-foot downwind clearances.
(d) Locate parking lots alongside roads to act as buffer zones. Do not place parking lots among
buildings. Expect additional snow accumulation around parked vehicles, and provide ample room for snow
storage away from roads and on the downwind end of the lot. Because curbed islands hinder snow removal
operations, they are not suitable in most cases.
(e) Parking aprons should be placed alongside, not upwind or downwind, of hangars and
(f) Orient surface structures with their longest side parallel to the winter storm wind. Winter
storm winds may come from a different direction than prevailing summer or winter winds.
(g) Doors are best located along the sides of the building, toward the upwind end. Doors on
the downwind end of the structure may be rapidly blocked with drifting snow: those on the upwind face are
difficult to seal.
(h) Orient large garage doors so they are nearly parallel to the wind, even if this results in a
building orientation that is perpendicular to the wind. Adjust this orientation slightly to assure that the doors
are not in the lee of the upwind corner of the building.
(i) Place structures in rows perpendicular to the wind. Allow enough space between buildings
to permit effective snow removal. Each row of structures should be placed directly downwind from the
(j) Provide snow dumping areas to eliminate large piles or windrows of snow in the camp area.
Piles and windrows are obstructions which increase future snow removal requirements.
(k) Avoid decorative earthen berms around buildings and in parking lots. Berms can cause
additional snow accumulation problems and interfere with snow removal operations, disrupt building access
for maintenance and fire protection, and create moisture problems at the foundation wall.
(3) Sources of climatic information. Due to the relatively brief developmental period and sparse
population, long-term climatological records are primarily unavailable. Short-term observations are often
incomplete and may be misleading. Extrapolation of available records is frequently necessary. Governmental
agencies are generally the best source of information with the principal source for worldwide data the
National Climatic Data Center, Federal Building, Asheville, North Carolina 28801. Much of the information
available at Asheville is supplied by the Environmental Science Administration (ESA). DOD agencies should
request climatic information through the U.S. Air Force Environmental Technical Application Center
(ETAC), Building 159, Navy Yard Annex, Washington, DC 20333. TM 5-785/AFM 88-29 contains
information obtained at military sites.
1-5. Cost Factors. Many cost factors must be evaluated to provide a cost effective design.
a. Labor. Skilled labor is usually in short supply locally, so costs are high. Minimizing skills needed and
scheduling work to occupy each worker's time fully will reduce total work time. Providing housing