On the WD-1 wire one of the conductors had a raised edge on one of the conductors jacket. I remember learning the ridge identifies the ring and the round is the tip. I also remember learning in AIT that the tinsel strength of WF-16 was 225 pounds. My first duty station in early '91 was Panama and the cable dogs were pulling a WF-16 wire for a teletype circuit from a warehouse on one side of Corozal next to the canal across the highway to our switching site next to the bank. We went from roof top to roof top, under the railroad tracks through the trees across the highway. My partner and I was working the wire over the roof of a warehouse. We didn't have any ladders so I had to climb on his shoulders on to the top of a Quonset hut, jump on to an eave then haul ourselves onto the roof of the warehouse. After we got done working the wire I found some old WF-16 clove hitched to a vent stack. Remembering the tinsel strength I told my partner since I was just 130 pounds I was going to use the wire to climb off the roof. I get into a perfect piked repelling position of the side and "DOINK!" one of the pairs snapped and the other burned through my hand. I land on the sidewalk 20 feet below (probably not quite that high but it seemed like a long time in flight). I laid there waiting for the lightning bolts of pain to tell where I was hurt but they never came. I got up and told my partner "Don't tell SGT Brown, he'll be mad."
That was WF-16. The green pair had ridges so it could be identified at night by feel. I've never seen WD-1 or WD-1A that had ridges nor field phones that were T/R sensitive. Must be an Army thing!
