Comment by jandrese
16 hours ago
Looking at the pictures it looks like the fiber itself might be inside of that spiral metal conduit in the middle and the outside is just abrasion protection. There are way too many strands for that outside bit to be the fiber. It's obviously bad that the outside plastic disintegrated, but it looks like the buried cables might be fine.
I have a similar problem on my car where the 12v wiring is disintegrating like this because the manufacturer tried to switch to a more environmentally friendly wiring. Now the wire jackets turn to dust at the slightest touch or if they vibrate too much. I'm forever tracking down intermittent shorts in the wiring harness.
The metal coil will hold the actual fibre itself, yes - after a few more layers of protection. This is what is usually called “armoured” cable and is suitable for suspension and direct in ground. Dunno why he’s using it indoors.
Honestly, this writeup is… weird? Dude doesn’t know you can terminate fibre at home with like $50 of gear?
I had the fucking fox attack a freshly laid 500 meter line, literally the day before I was going to stuff it in conduit and bury it. Didn’t just break the fibre, she (I know this fox, well) chomped it into pieces, hauled on the exposed Kevlar, generally had a party.
Did I despair? Did I launch a baby complete with bathwater into the sun?
No. I bought a cleaver, some alcohol wipes, some stripping pliers and a whole bunch of mechanical terminators.
Needn’t have worried. Repaired it, outdoors, first attempt, in the rain, and have since buried it - no problems five months on.
Hey actually I didn't know! It's my very first time dealing with fibre networking so I just maxed out the supposed durability specs. I figured I'd rather go overkill than regret not having done so. Ironic I know.
Unfortunately I can't easily dig the cable out and bury it again in this case. I'll have to figure out how to pull a new cable using the existing cable through the PVC conduits as the cable shares a larger conduit with multiple other fibre and Ethernet cables. The whole project was orchestrated remotely in a different timezone with me giving the electricians instructions over WhatsApp photos and audio recordings, so that limited what I could realistically control onsite back then. Often the contractors would proceed with a do first ask questions later approach while I was still asleep. The networking project was holding up the entire home renovation so everything was learnt and planned in a short amount of time.
AFAIK fibre splicing and terminating tools are very expensive. Do point me in the right direction for the $50 tools and I could go get some and DIY.
> AFAIK fibre splicing and terminating tools are very expensive.
They're more like $600 expensive than $6000 expensive these days. For very low budget, you could go with a mechanical (aerobic) splice; it's more loss, less robust and takes up more space, but doesn't require a fusion splicer.
If you want to pull another cable:
- secure a string to the old cable
- pull the cable out the other end, pulling the string through
- secure the string to the new cable
- pull the string out the other end, pulling the new cable into position
9 replies →
Yes, the whole thing is built like bike brake cables, with a spirally metal support core, the goodies up the inside, and then a nylon braid and PVC jacket over the top.
I have issues with the PVC-jacketed cables under the bonnet of my nearly-30-year-old Landrover, where the plasticiser has been baked out of the insulation and they've gone brittle. Worst affected are the wires to the fuel injectors and the lambda sensors, presumably because the former are at the top of the engine and get reflected heat off the bonnet, and the latter because they're near the literally red-hot exhaust downpipes.
That's okay for an old vehicle that you'd expect to repair, though.
I've seen the same problem in three-year-old Toyotas, and that is Just Not On.
Your car wouldn’t happen to be a Volvo would it?
Mini Cooper. From what I've heard it's a BMW thing.
BMW and Toyota have famously used bio-derived insulation reported to be like catnip for rodents.
The bio-oil plasticizers also migrate out more quickly in thermal cycling than the old dead dinosaurs approach. Hilariously, when I asked my mechanic about getting an M5, he laughed and explained that the radiator components are known to turn brittle and crack after 5-6 years because of this.
(I don't envy automotive folks. The stuff they have to deal with is next level.)
1 reply →
1990s Mercedes would be my guess.
The outside strands are kevlar. The fibers are inside the armored core often inside another jacket.