boxes have a removable plug in the bottom of each
shore-line connection box and the other end will be
box for inserting the cable.
connected to the lightning arrester box on the ship.
Figure 6-47 shows the basic circuit
Each set of shore-line telephone leads from
arrangement for a typical lightning arrester box.
the switchboard pass through a lightning arrester
Each lead of an incoming line has a 5-ampere fuse
box and end in a shore-line connection box. The
and a set of carbon contacts in the line. If lightning
lightning arrester box protects the telephone operator
strikes the line, the fuse will blow to open the circuit
and telephone equipment should lightning strike the
to the switchboard equipment. The carbon contacts
incoming telephone lines.
will fuse together to provide the incoming potential a
path to ground. Most ships have a lightning arrester
The lightning arrester and shore-line
box on each side, port and starboard.
connection boxes may be combined. The installations
vary from ship to ship, and those mentioned here
serve only as examples of the variety you may find in
the fleet. On a large ship you are likely to find one
arrestor box and one connection box on each side,
port and starboard. Some small ships have only one
lightning arrester box in the circuit ahead of the lines
that branch off to the port and starboard shore-line
connection boxes. Normally, standard electrical
connection boxes are used where the incoming shore
lines connect to the ship's lines. A practice that is
gaining favor calls for the use of amphonel-type,
multipin, jack-and-plug combinations. In such a case,
the plug fits the shore-line connection box and the
jack attaches to a portable cable that is run to the
Figure 6-47.--Shore-tine connections.
local shore-line connection box on the pier. The new
Figure 6-46.--Current flow test set controls and indicators.