To prevent loss of the transmitter, use a lanyard to tie it down. When in the defense, units normally communicate by wire and messenger instead of by radio. Your leaders will often have you lay the wire and install and operate the field phones. A surface line is field wire laid on the ground. Lay surface lines loosely with plenty of slack.
Slack makes installation and maintenance easier.
Surface lines take less time and fewer soldiers to install. When feasible, dig small trenches for the wire to protect it from shell fragments of artillery or mortar rounds. Conceal wire routes crossing open areas from enemy observation. Tag all wire lines at switchboards and at road, trail, and rail crossings to identify the lines and make repair easier if a line is cut. An overhead line is field wire laid above the ground.