3-69. Which of the following means should
be used for water drainage from a
1. Ducts that slope down from the
2. Pumps installed in the manhole
3. A central drain hole, a dram line,
and a sump for the manhole
4. A series of drainage holes bored on
the deck of the manhole
3-70. When a duct line is set in concrete,
there should be a minimum of how
many inches of concrete around each
line of duct?
3-71. Which of the following methods is
used to clean ducts?
4. Each of the above
3-72. You are pulling multiple cables
through a duct. You should pull the
cable at what rate?
25 feet per minute
35 feet per minute
3. 50 feet per minute
75 feet per minute
3-73. Before you enter an underground
structure, which of the following
people must certify it as being safe?
1. Safety chief
2. Safety officer
3. Confined space manager
4. Commanding officer