TM 5-852-1/AFR 88-19, Volume 1
movements are so serious that the "rigid" type structure
Low ground-pressure tractor trains may be used to
should not be used unless conditions are such that
transport men, materials and equipment over frozen,
differential movements cannot occur.
Multistoried
snow-covered terrain in winter. Frozen lakes and rivers
concrete frame buildings and other buildings with
are frequently used very effectively for such
considerable structural rigidity should be separated into
transportation. Ice bridges can be used for crossing
independent units, by expansion joints and double
rivers and lakes by wheeled, tracked or sled equipment.
columns, at locations where differential movement can
Materials can often be stockpiled at convenient locations
be anticipated, such as at connections of wings to the
during the summer for surface transport to the site in the
central section of a building and at intervals along a long
winter. For protection of the terrain, operations on the
rectangular building. Control joints should be employed
natural tundra surface in summer are generally
to prevent or minimize unsightly cracking of exterior
prohibited in Alaska. Vehicles with rubber tires of very
facing. The principle of resisting differential movements
low ground pressure (1 to 2 pounds per square inch) are
by extreme rigidity is not recommended because the
an exception. In some areas, such as natural preserves,
costs are high, the forces cannot be estimated very
various other restrictions or permit requirements may
closely and failure is common.
apply. Other countries also have land-entry and land-use
j.
Specialized building design criteria and
regulations for northern regions.
c. Construction equipment. Heavy equipment
guidance are given in TM 6-852-9/AFM 88-19, Chap. 9,
is essential in arctic and subarctic construction. The
and design criteria and guidance pertinent to foundations
severity of construction and climatic conditions usually
for buildings are presented in TM 5-852-4/AFM 88-19,
makes the use of tractors weighing at least 30,000
Chap. 4.
pounds, of 10-cubic-yard dump trucks, of 2-cubic-yard or
larger shovels, of heavy ripping equipment, etc., very
5-8.
Construction management and practices
important.
All motorized equipment should be
a. General. Construction management and
winterized, including insulated cabs and facilities, fire
procedures in arctic and subarctic regions differ from
retardant engine shrouds, and heaters to protect
those in temperate regions because of deep seasonal
personnel from severe cold, wind and snow. Removable
frost, permafrost and climate. The environment and
cleats on tracked vehicles (i.e., grousers) or other special
short construction season critically affect field operation
traction devices and winches are frequently necessary.
schedules. Remote, isolated construction sites served
Preventive maintenance plays a key role in equipment
by long and difficult supply lines mean that mistakes in
operation, and a strict lubrication schedule should be
planning are time-consuming and costly.
A highly
maintained on all pieces of equipment. Cold weather
competent management team, possibly having
pre-operation, starting, warm-up and operating
decentralized authority with centralized support, must
procedures should be adhered to by equipment
carefully plan and organize field activities, and conduct
operators. "Cold-soaked" hydraulic systems not being
an intensive field inspection effort. Designs and cost
used are especially vulnerable to failure upon start-up at
estimates are strongly influenced by the construction
about 30F or lower.
Tires in extremely low
procedures and schedules that are feasible in the arctic
temperatures become brittle and are easily punctured.
and subarctic regions.
Brittle fracture of metal parts at temperatures around
b. Methods of transportation.
40F or lower is a potential problem, and all equipment
(1) Air transport is one of the principal
should be inspected regularly to locate cracks and
modes of transport to arctic and subarctic field sites. If a
breaks.
All cracks should be repaired when first
landing strip does not exist near the site, helicopters or
observed by pre-heating before welding, and broken
float-, ski or wheel-equipped small planes may be used
parts should be replaced. Statistics on one U.S. Army
in initial project stages, depending upon the available
Corps of Engineers project in Alaska showed that the
surface conditions.
In winter, fairly heavy wheel-
availability of equipment was reduced 2 percent for every
equipped planes can use ice landing surfaces. With
degree lower than 20F.
construction of a serviceable conventional runway, heavy
d. Cold and the worker. The efficiency of
planes can operate more permanently.
labor on construction projects in the Arctic and Subarctic
(2) Where a suitable road or waterway is
varies with the experience, attitude and morale of the
present, or where an access road, even of an expedient
workmen as well as working conditions on the job. Cold
nature, can be constructed, construction materials and
and darkness during the winter months combine to
equipment can be brought to the construction site by this
create safety and operational problems that directly limit
route. However, rivers and the arctic coastal waters
productivity. The degree of acclimation of the worker
have only limited ice-free periods during which they can
and how adaptable the worker is to cold are very
be used for water transport. Sometimes a north-flowing
important in all classes of labor and they directly affect
river may be open for upstream navigation before its
output.
For example, Alaskan contractors re
mouth becomes sufficiently ice-free in the breakup
period
to
permit
entrance
from
the
sea.
5-5
Previous Page
