The Legend of Arni’s Woodpecker

I’m going to tell you a story that isn’t mine. It’s Arni’s. Arni is a 32-year tech with the kind of territory most veterans would kill for — established residential plant, manageable density, a fishing lake on the way to the office that he has used for diagnostic time more than once. He keeps his territory in the kind of shape other techs notice. Anything broken in Arni’s territory gets noticed by Arni first, because Arni knows what “normal” looks like there better than most people know what their own kitchen looks like.

This is the story of the one fault that beat him. We tell it at the office. Arni does not tell it at the office. Arni walks out of the room when somebody else starts telling it. I have not yet had the courage to find out what Arni thinks of the version we tell, but I suspect he has opinions.

It started with a node showing intermittent upstream issues. A cluster of customers calling about latency. A few about disconnects. No clear pattern to time of day. The PNM data showed in-channel frequency response ripple — the upstream wasn’t flat anymore, it had a visible standing-wave shape — and microreflections with a time delay that put the fault somewhere downstream-distant from the node but not at any active equipment. Some days the data was clean. Some days the ripple was textbook. Whatever was wrong was a fault that came and went on its own timeline, which is the kind of fault that drives a methodical man to consider a less methodical line of work. Like sales.

Arni did the math the way Arni does math, which is methodically, with a pencil, on a notepad with a coffee stain on it. Time delay on the microreflection put the fault somewhere in a 200-foot window of distribution cable. That’s a precision number on paper. In the field, it means: somewhere along a stretch of .540 hardline that ran from a riser pole at the road, across an easement, into a wooded back lot, where it transitioned aerial-to-buried on a final pole and went underground for the last leg to the customer’s tap.

Two hundred feet. Forested. Property line ambiguous in two directions. Half of it not visible from any road or driveway. Most of the cable not visible from below because it sat above brush level. Nothing on the route that anyone had ever had reason to look at, because none of it had ever caused a problem before. Arni’s territory does not have problems. Arni’s territory has, on this one occasion, a problem.

He walked the route the first time on a Thursday afternoon. Found nothing. Climbed two poles to inspect spans. Found nothing. The PNM data was clean that day. He went back to the truck and noted, in his careful pencil, “no apparent fault.” That should have been the end of it. It was, instead, the beginning.

The fault came back the next week. PNM data showed ICFR ripple, microreflections at the same approximate distance. Arni went back. Walked the same route. Found nothing. Climbed the same poles. Found nothing. Drove off swearing in two languages, one of them the Icelandic his grandfather had insisted on teaching him, which he reserves for situations where English is insufficient.

This continued. By the third visit he had walked that easement enough times that the property owner — a retired schoolteacher who had initially viewed Arni with the suspicion appropriate to a stranger in coveralls walking past her hydrangeas — had started bringing him coffee and asking polite, curious questions about the diagnostic process. Arni now had to be social as well as frustrated. By the fourth visit, I am told, he had briefly considered changing careers. By the fifth visit he had gotten the kind of look on his face that you do not interrupt.

The damage was on the back side of a span between the second-to-last pole and the dip pole. You couldn’t see it from the ground because brush blocked the view. You couldn’t see it from the road because trees blocked the line of sight. You couldn’t see it from the front of the cable on the pole because the damage was on the back side, facing into the woods, against the wood of the pole itself.

It was a hole. Drilled cleanly into the .540 jacket and through the outer shield, exposing the dielectric. Round, neat, and — in retrospect — exactly the diameter you would expect a determined woodpecker to produce in something that looked, from a tree’s point of view, more or less like another tree. A Pileated woodpecker had identified Arni’s distribution cable, decided it had structural promise, and put a hole through the outer shielding of about seventy thousand dollars’ worth of regional plant.

I know you want to know what Arni said. I am told what Arni said. I am not authorized to repeat it.

The fault was intermittent because woodpeckers do not drill a hole once and walk away. They come back. They expand it. They occupy it. Sometimes there’s debris in the hole — bark, insulation fibers, on at least one occasion a small mushroom we chose not to identify. The breach changed shape with bird traffic, weather, and the seasonal disposition of whatever the bird had going on. There was no pattern to the fault because there was no pattern to the bird. The bird does not file a route plan.

Woodpecker damage to utility infrastructure is, it turns out, a known industry problem. Utility companies have entire mitigation programs — rubber sleeves, reflective deterrents, in some markets contracts with wildlife biologists. None of this was news to anybody who had been in the industry for any length of time.

What was less typical — and what made this case specifically Arni’s, rather than just another routine pole-damage call — is that the documented industry problem is mostly damage to the wooden poles, not to the cable. Birds excavate the poles. Poles are wood. Poles look like trees from a woodpecker’s point of view, which is the only point of view a woodpecker has, and the standard mitigation playbook is built around protecting poles. Cable strikes happen, but they are uncommon enough that most field techs go their entire careers without seeing one. Some birds, for reasons no one is paid enough to explain, decide the cable on the strand looks more interesting than the pole it’s mounted to. Whether that is ambition, confusion, or some specific grievance against coaxial design specifications, no one can say. This particular bird flew past several perfectly good poles to drill a hole in the cable on the back side of a span. None of this had ever happened to Arni’s territory before, because Arni’s territory does not get problems, except for this one time when it got an unusually specific one.

We replaced — well, Arni replaced. Arni cut the damaged section out and put a splice in. Twenty minutes of actual repair, after weeks of trying to find the thing he was repairing. He recovered, mostly. He still doesn’t tell the story. He has, however, started carrying a pair of binoculars in the truck, and he glances up at any cable run that goes through woods now in a way that suggests he is no longer assuming anything.

Here is where the story becomes a CPAT story.

The methodology Arni used was the only methodology available to him: look at PNM, estimate distance from time delay, walk the route, hope to find visible damage. That methodology depends on the fault being visible when you happen to look at it, in good light, from the right angle, on a span you happen to inspect, on a day the bird is not actively occupying the cavity. The methodology fails on intermittent faults. It especially fails on intermittent faults in wooded back lots where most of the cable is not inspectable from the ground.

The CPAT ingress detection methodology changes the question entirely. The IRX1 sits at the head-end, listening on the upstream return path for a known signature to arrive where it shouldn’t be. The tech carries an ITX2 portable ingress transmitter into the field. As the tech walks or drives the suspect route, the ITX2 transmits its signature continuously. Anywhere the cable shielding is breached — anywhere there is an ingress path, by definition — the ITX2’s signal enters the cable and travels back to the head-end. The IRX1 detects the signature. On the field side, the tech has the Mobile App / RIM open on a phone or tablet, showing live signal-strength readings from the IRX1, with audio tone keyed to the level. Closer to the breach, the tone climbs. The match between “the ITX2 was here at this time” and “the IRX1 picked up the signature at this time” localizes the breach to the span. Often to the specific clamp.

The methodology doesn’t care whether the fault is intermittent. It doesn’t care whether the bird is currently home. The hole is an ingress path whether the bird is in it or not, whether there’s debris in it or not, whether the customer’s modem is currently complaining about it or not. The ITX2 does not depend on the customer’s service being loud at the moment of detection. It puts a signal into the path that wasn’t supposed to exist, and the path tells you exactly where it is.