up and mix) the snow, and thus maximum effi-
this allowed the snow blower unit to do a fair job
ciency for us was obtained when the snowblower
of stripping the ice. However, we found that the
tackled the windrows left by the bulldozer blade.
machine could not generate enough down pres-
sure in many cases to adequately strip the snow
from the ice. More importantly, the machine had
to move very slowly and the volume of snow
RUNWAY CONSTRUCTION
removed from the area per unit of time was very
Comparing the natural ice survey results to the
small compared to the rated capacity of the blower.
selected final grade, we could easily determine
Thus, it became obvious that the most efficient
the amount of grading that will be required and
use of the snow blower was to "feed" it large
the areas that will require the most effort. Using
mounds of loosened snow, where it could make
this information, and all known constraints
reasonable forward speed while ingesting signifi-
(workforce size, seasonal operating windows,
cant quantities of snow.
equipment resources, and support requirements,
A similar lack of efficiency was found when
such as fuel), the management team can refine the
the snowblower followed the ripper. Forward
construction schedule.
progress was slowed by the need 1) to remove
some of the snow not detached from the ice by
Up until this point in the construction sequence,
the ripper teeth, and 2) to break up the snow
the runway is fairly protected from solar influ-
slabs from the drum somewhat before the sec-
ences by having some snow cover. However,
the following steps will bare much of the ice
ond stage would accept them for ejection. Over-
surface and they should not begin unless ample
all, the volume of snow removed per unit time
time and cold temperatures exist to complete
with this scheme was also well below the blower's
the tasks and then recover the surface with a
capacity.
protective cap of snow. Of course this is only
The capabilities of the blower were better used
critical for sites like Pegasus where tempera-
by operating the snowblower along the wind-
ture and solar effects can cause melting during
rows generated by the grader. As noted above,
some periods of the year.
we used the bulldozer to further process (break
Figure 32. Ice surface following initial snow stripping.
34
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