BASIC SIGNAL COMMUNICATION

[Music] the army uses fieldwire extensively in combat areas and even in rear areas when time is limited this is because fieldwire lines are less likely to become damaged and can be installed much more rapidly than other types of lines field wire is laid by various types of wire laying devices known as real units the type use depends largely on the terrain and the length of the line to be laid the different real units require a varying number of men to operate them the personnel required to operate one real unit is known as a wire laying team before wire teams begin the installation of a wire system they receive instructions from a communications or signal officer these instructions include an outline of the general routes to be followed in laying the lines and whatever other orders are necessary for the teams to do the job the instructions cannot be too specific however as many circumstances will arise where the construction chiefs must use their own judgment after receiving instructions the wire teams move toward the command post area from which the lines will be laid since the real units cannot be allowed to group together around the switching central the teams laying the longest and most urgently needed lines are given precedence in making the initial installation when a real unit comes in to the command post area enough wire is reeled off for an overhead or underground construction the end of the wire is turned over to the wire chief who ties it into the switchboard if the switchboard has not been installed the wire must be connected to a telephone so that it may be tested back to the starting point as the work progresses wires are never left lying on the ground around the command post or other areas where they may be damaged by troops and vehicles they must either be buried or placed overhead the extra wire which has been reeled off as tied to a support and the truck moves out leaving part of the team to take care of the wire this permits the next truck to move in and begin its installation at the switching central without losing time after completing the special construction the men who were left at the command post follow along the line doing whatever is necessary to protect it they are shown following on foot however they follow in another truck if one is available in the meantime the part of the team with the real unit has gone ahead with laying the line stopping only when necessary the object is to establish communication as soon as possible at frequent intervals they stop to pull in the slack and tie the line to a support a slack line is important because it is less likely to be broken than a taut line further if a wire is broken the extra length is needed for repairs wires must be tagged at frequent intervals so they can be easily identified particularly where they parallel each other for a long distance the tag should be tied on in such a way that they can be removed easily they are marked with the number of the circuit and the name of the unit doing the installation lines must also be tagged at points of special construction such as where an overhead tie is made well where wires go through a culvert they are tagged where several lines running parallel to each other change direction and about a foot from where they are connected to an instrument or a terminal strip they placed the line on the inside of curves of practicable however when wire must be laid on the outside of a curve the unit stops to tie it to a support that will keep it off the road another job for the team arises when a reel of wire is exhausted the end of the wire is prepared for splicing while a new reel is placed in the unit the new reel is then spliced to the line meanwhile one team member connects a test telephone to the line at the far side of the splice the line must be tested from the far side of every point where the continuity of the wire may be doubtful when the splice is finished a call is made back to the switchboard when a line is to be over ten miles long loading coils may be necessary to increase the transmission range of the wire in order to be effective they must not be closer than two tenths of a mile from terminals neither can they be farther than a mile from a terminal these coils should be spaced about a mile apart the C 114 coil is protected by a watertight case it weighs about two pounds the conductors of one end of the line are fastened to the binding posts on one side of the coil when the binding post is tightened a contact pierces the insulation and establishes the connection the line is continued from the other side of the coil the wire should be tied to a support to take the strain off the coil connections the ends of the wire should not extend more than a quarter of an inch from the terminals the four conductors fit into grooves when closing the cover the wires must be in place field wire lines are always passed under a bridge or colored if one is available where a team has to cross a highway or a railroad at a point of special construction like this the men do only as much as is necessary to enable the rest of the team who are following along the line to complete the job in this way no time is lost in establishing communication one team member pulls off enough wire to make the crossing he tags the lines other members prepare to pass the wire through the culvert the lines are cut and the tagged ends are given to the other men the ends from the reel are taken to the other side of the road where they are prepared for splicing the wire is passed through the culvert at the far side the lines are spliced together again meanwhile equipment is replaced when the splices are completed the lines are tied to a stake and the truck moves on an overhead must never be made over a railroad because of the danger to persons on top of railroad cars when there is no bridge or culvert under a railroad the lines are tagged cut and passed under the rails the wire is then spliced together again while the wires being spliced one member of the crew digs a trench from the track to the edge of the improved area he places the wire in the trench the lines are tied to a stake at the far side when there is no bridge or culvert at a road crossing enough Flair should be reeled off to make an overhead tie at least 14 feet high a main highway should have a clearance of 18 feet the extra wire is held by tying the lines to a support at times the quickest and easiest way to cross a secondary dirt road is to bury the wire extra wire is reeled off this extra wire is to replace the Buried line in case it is broken a trench is dug straight across the road this trench should be at least six inches deep the wire which has been tied to a stake he's laid loosely in the trench when the unit comes to a stream enough wires reeled off to make an overhead crane this wire must have good insulation and contain no splices had a stream crossing wire is unreeled and tied in place the same as at a road crossing in the meantime while the unit truck is laying the wire the team members who were left back at the command post follow up for special work they make sure that the wire is off the road but it lies close to the ground and does not hang over obstacles however the team's main job is to finish the special construction work started by the other men at points where the wire might be damaged at the culvert the slack is pulled out of the line at points where the insulation is apt to wear off the wire is protected by a friction tape the line is tied to a stake at a high point this keeps it from coming in contact with the water the tags are placed about a foot from the stake the same procedure is followed on the other side of the culvert at the railroad track the men fastened the wire and bury it to complete the overhead tie the men put on their line equipment the lines are carried up the trees they are first tied on the far side of the road by a loop nut when one knot is tied the soldier on the other side of the road takes up the slack and ties it in there the line should not come in contact with branches which sway in the wind the job is finished by tying in at the base of the tree when the tie is completed hi trucks can pass clear the lines if there are no trees or telephone poles Lance poles can be used for an overhead they can be lashed to a support or guide with field wire where the trench was dug across the road the linemen fastened the wire and bury it ordinarily a stream is crossed by an overhead tie just as in the case of a road crossing except that the tie need only be high enough to clear the water at all times while the team members are following up with special construction work the unit truck arrives at its destination enough wire is reeled off to complete any special construction that may be necessary the wire is tied into a support a call is made back over the wire to see that the line is in working condition the taglines are then given to a member of the operating detail who ties into the switchboard after the installation a final test is made over the entire line if the operating detail had not yet arrived a telephone would be attached and a member of the team would be left at this point to inform the detail as to the location of the lines [Music]