MIL-HDBK-1025/10
will not produce sparks in striking the manhole cover Do not use an open flame or salt to thaw
ice around or over the cover. An open flame may cause an explosion if a combustible gas mixture
is present in the manhole. A salt solution seeping into the manhole may contribute to cable
corrosion. Make test holes in the ice to locate the edge of the manhole cover.
c. A line or cable locator is useful in finding manhole cover locations when records are
inadequate or when marking points are covered with ice and snow. If the exact location of the
manhole is not known, a small channel may be cut from the outer edge of the general location to
the center of the area where the cover should be. If the manhole cover is icebound, use enough
hot water to melt the ice around the edge of the cover.
d. Do not leave a manhole cover in a location where it will present a hazard. If the cover
cannot be left near the manhole opening, skid the cover to a safe location. If necessary, place a
warning device near the removed cover.
e. Before removing a manhole cover, mark the cover and the frame with a piece of chalk
so the manhole cover may be replaced in its original position. Improper alignment of the cover
within the frame may cause considerable noise when vehicles cross over the covers. When the
noise condition does exist, place a thin layer of oakum (or similar material) in the cover seat of the
frame.
f. In a traffic area, the manhole cover is removed in a direction that will prevent personnel
from falling into the path of traffic should the manhole cover hook slip during the cover removal.
The removal position should permit observation of oncoming traffic. When possible, insert
manhole cover hooks in the hook holes on the side away from moving traffic. Place the covers of
opened manholes on the side away from traffic, when conditions permit. In case of two section
covers, place one section on each side of the opening.
g. When this is not practical, insert the manhole cover hooks in the holes that permit the
cover to be moved in the direction of traffic. Keep the oncoming traffic under careful
observation.
h. Replace manhole covers with the same care as used for removing them. Be careful that
manhole covers are properly seated when replaced. The bearing surfaces should be free from dirt
or ice which might prevent them from fitting properly.
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