Field telephone wire is distributed on large drums and these are then fitted into different frames to allow them to be rolled out and laid where needed. The cable drums themselves need some protection from the elements to ensure the wire is in the best condition it can be as degraded wire will result in poor quality transmissions down it. The wire is made of copper and covered in insulation, lengthy exposure to UV light, moisture or frost will start to break down the insulation and then the copper inside is open to moisture and in turn corrosion. Special covers are issued to protect a reel of D10 wire from the elements and these are made of green nylon in two parts that open up to allow the reel to be fitted inside:
Inside the cover is an adjustable strap that goes around the edge of the cable drum and can be drawn tight to prevent a half filled wire from unravelling and tangling itself. It is made of very heavy duty nylon with a friction buckle to allow it to be tightened:
The drum is placed inside the two halves of the cover, which are then secured around the edges with six sets of straps and friction buckles to ensure a tight fit:
Note also the draw cord that allows the edges to be drawn even tighter for better weather proofing.
The covers are printed on both sides, with the top having the NSN number for the cover and a reminder that when paying out cable, it needs to come out of this side of the cover:
The bottom of the cover indicates that this is the side to face down and has additional D-rings to secure the cable and its cover when not in use:
Also included with the cover are a pair of vinyl self adhesive patches:
I believe these are to cover the central hole of the cover when the cable is not to be used for a long period of time to further protect it from degradation.
When full, the drum inside this cover would hold 100m of the cable allowing lengthy communication wires to be laid in one piece with the use of a cable winder, an example of which we will be considering in the next few weeks. In this photograph a pair of the drum covers can be seen on a manpack carrier: