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Comment by wickerman | Hacker News Reader

I didn't know about this at all! Why is it not done anymore?

For telephone exchanges "Plastic flow" was the reason we were given - if you lace plastic cables and the lace is too tight then the plastic will flow and may expose the wires / cause internal shorts etc. Also lacing can increase cross talk (because the wires run beside each other for long distances).

Cable lacing was used in old "step by step" telephone exchanges which used cotton wrapped wires. When the new fangled cross bar exchanges came in, PVC insulation was the cable of choice, this suffered from plastic flow. The recommended way to run cables was just throw them in the cable trough (the steel shelves running above the equipment, which were also good for the occasional nap). They were looking at many years of installation, I imagine cable ties cause the same problem, but installations probably don't last as long now days, and the cables aren't twisted pair. Source: Ex telephone exchange tech.

> ... (the steel shelves running above the equipment, which were also good for the occasional nap).

You've just given me a fun idea for the office. :)

It was not unknown after a long lunch to find a tech having a little nap. I can't imagine that happening these days, there'd be forms to fill out, meetings with HR....

Thanks for the insight! I wonder if ability to resist creep[0] has ever been much of a goal when formulating wire insulation. Or is this "plastic flow" a different phenomenon than creep? For installations that are intended to be long-term (inside walls, buried under ground or concrete, etc.), it seems like the failure mode you describe would be really annoying to fix.

[0] https://en.wikipedia.org/wiki/Creep_(deformation)

Most cables had "spare pairs" in case problems occurred. In a hundred pair cable, there'd be 10 unused for example, and if a short / open developed somewhere then you'd use a spare pair. I remember there was a procedure for replacing a cable in a form (the tied set of cables), but not something I ever did, they were in the process of phasing out lacing when I started and I only did it for a few years, there were these new things called "microprocessors" which seemed interesting.

It is still done on aircraft (where vibration and consequence of failure is higher).

It's not done much in industry because it's slower than zip ties or velcro wraps (which also require essential zero skill).

Likely same reason as many, many other things: the modern 'automated' version (tie wraps usually) is easier, cheaper, faster. And has the standard consequences which unfortunately get ignored: requires close to no skill, plastic, seldom reusable, probably won't get recycled and ends up as waste eventually. Lacing has some of those disadvantages as well though.

One big problem with lacing is that it's one long string of knots instead of many individual tie points. You can always cut a zip tie and replace it with another. For lacing that was cut in the middle fixing is a slightly more involved process. So unless it's a final install it could bring some headaches. It's very unforgiving if you realize you got something wrong.

With regards to the material used, I have never used or seen waxed linen cord. It was always purely synthetic (plastics) possibly due to cost, availability, or performance.

> For lacing that was cut in the middle fixing is a slightly more involved process.

Only if you are speed lacing and do not knot the intermediate restraints. If there is any chance that you will need to break apart mid line you add a stable knot at each intermediate and can simply break between any tie.

True and this may help if you just want to detach 1m of cable from one end (perhaps to route it another way). But replacing one cable in such a bunch is either a nightmare or a serious time sink, depending on how you look at it.

Zip ties are cheaper and faster, velcro might not be cheaper but still faster and a lot more flexible. This being said if I want to send a rover to Mars (so definitely a final install) I will not use zip ties :).

Why is it a negative consequence that the replacement requires no skill? Turning on a light switch requires far less skill than trimming wicks for oil lamps, but I'd consider that a feature not a bug.

Creating a wiring loom is a skilled task. If you keep those same skilled workers and make part of the job easier that's probably a good thing.

What sometimes happens is that a PHB will see the switch away from lacing and to cable ties and think that the rest of the job is now lower skilled, and they put lower skilled workers on that job. This is bad, because wiring looms are tedious to inspect and test, and we now need better inspection and test to compensate for the lower skilled staff.

Also, because cable tying tends to be done with a hand tool (reproducable tension, uniform cuts, speed of assembly etc) there's a small risk of repetitive strain. I used to use this tool, and it was okay if I was doing the entire loom, but it sucked if I had a big pile of other people's looms and all I was doing was adding cable ties. https://uk.farnell.com/duratool/d03033/cable-tie-gun-stainle...

Panduit has an even nicer, more ergonomic one- I use a Panduit GTS at work, and I love it.

That panduit does look lovely.

Here's a link to one model: https://uk.farnell.com/panduit/gts-e/tool-cable-tie-installa...

Good hand tools are always worth the money.

It's a bit double. On one side: yes it's obviously better, faster, if anyone can do it. On the other hand learning a skill is valueable as well.

A person can learn another (likely more valuable) skill in the time that they would have had to take to learn to lace cables.

Labor is expensive, materials are cheap. Cable lacing doesn't protect the wire from abrasion like wire loom does.

For bigger bundles of wires there's also the "plasic flow" (basically the weight of the bundle causing the cable to cut the insulation) issue another commentor mentioned that loom is basically immune to.

The comments below the article outline a few reasons. Overcompression of the cables, difficulty making changes later, etc.

Cable ties and velcro wraps seem to make more sense.

The comments mention overcompression as a problem of zipties, not cable lacing.

“Zip tie” cable ties aren’t only the ones that risk overcompression but also have a big “box” that juts proud from the bundle which can interfere with threading, moving other things around it, can snag on things passing by, etc.

And people in a hurry with dull tools inevitably cut off the tail of the zip tie less than flush, and at a 45 degree angle. Those things will gouge up the back of your hands and forearms and draw blood. They're not only a hazard to humans but also to other fragile cable jacket that might run up against it during installation.

Zip ties are totally banned from the fiber meet me rooms at many major internet traffic exchange points.

Not sure why you're getting down voted. As part of our stand procedure we have to file down zip ties because it caused too many issues with damaging cables - and having been sliced while inspecting a unit, the fact they are now all nice and smooth is fine by me.

to answer your question, because. because they can and because it's easier than actually engaging with content you disagree with.

Cable ties can cause friction issues over time. They are all but banned from Airbus and Boeing aircraft unless you have some sort of silicone tape or fabric round-it beneath for protection, at which point it's easier for most engineers to just design it with lacing cord.

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