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Other anchor rod configurations may be used with a concrete pad, but the size and
depth of the pad must be at least as large and as deep as shown. The anchor rod and
its attachment to the foot that is to be imbedded in the pad must have at least the
strength of the anchor supplied with the tower kit.
Rock Anchors
Expanding rock anchors or bonded rock anchors are the best choice for Class 0 and
Class 1 soil. Rock drilling is hard and tedious work. It requires special equipment, in-
cluding a compressor and air drill. When needed, rock anchors should be installed by,
or with the advice and assistance, of a local contractor familiar with this type of anchor.
In all cases, the recommendations of the anchor manufacturer should be followed. Ber-
gey Windpower can also provide advice on rock anchoring.
Customer-Supplied Anchor Rods
The oval eye anchors supplied by BWC allow guy wire thimbles to be installed, prevent-
ing sharp bends in the guy wires. Any alternative anchor rods should incorporate simi-
lar provisions.
Guy Wires
Guy Wire Slack
There must be visible slack in all guy wires during all phases of tower installation. It is
possible to have too much slack or too little slack. The following discussion is aimed at
defining these conditions.
Unless the anchors are placed precisely in their correct locations and the site is perfect-
ly level, some guy wires will tighten and some will loosen as the tower is raised or low-
ered. For this reason, all guy wires must be watched and adjusted as needed through-
out the tower raising or lowering process.
When a guy wire loses its slack and becomes tight, there is no easy or obvious way to
tell how much tension there is in the wire. A wire that becomes tight can quickly apply a
very large force on both the anchor and the tower to which it is attached. If the tower
lifting or lowering process is continued, the force may increase to the point at which the
tower will buckle, causing it to fall and endanger people, vehicles, or equipment nearby.
When the tower has been assembled and is first lifted slightly off the ground to test the
winch anchor, the lifting wires running from the top of the gin-pole to the tower should
be studied. They will all have a certain amount of droop or slack. Studying the tower's
top lifting wire will give all members of the lifting crew a good idea of slack. Make sure
that the side guy wires have noticeably more slack than this reference wire. They
should not, however, appear sloppy. A droop greater than three or four feet should not
be allowed to develop during the raising/lowering procedure.
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