Figure 1-19. Wire construction across roads,
using lance poles.
c.
Lance poles used to support aerial field wire lines must be guyed at each pole. Each pole
has two guys at right angles to the direction of the line. Each tenth pole is four-wire guyed, with two
guys on each side of the line at a 45-degree angle from the line at the one to one ratio. The length of
each span will vary according to the storm loading in that particular area. The normal span is 100 feet.
d.
Other methods of crossing a road. This can be done by placing the lines through a
culvert, installing aerial lines, or burying the lines. For hard surfaced roads that are subject to wheeled
vehicle traffic and do not permit burial, the wire may be laddered. This is done by cutting the field wire
and by splicing one or more lengths of twisted pair to each conductor. These lines are then laid across
the road in parallel paths at distances greater than the longest vehicle expected to use the road. The ends
of the laddered arrangement are spliced to the original conductor on the other side of the road in the
identical manner. When properly staked, these laddered lines (each rung serving as a single conductor)
will provide initial communication, but should be replaced by an aerial crossing when the line is policed.
1-27
SS0440
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