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The Problem Of Unused Cabling
Makarand writes "Technological advances constantly render functional cable obsolete by
demanding data transfers at higher rates which older cabling cannot
support. New cables that support higher data rates are laid right over older wires.
The old wires are simply left in place and abandoned. This interesting article talks about the
problems
caused by abandoned cabling. According to an estimate several billion feet of
abandoned cable lies unused in the plenum spaces of buildings that allow air to circulate
creating a fire hazard. Also, very few firms currently worry about removing cabling when they
move out of a building."
Wonder how much it would cost to remove and recover the metals in unused cables, and would it be offset by the sale of the metal?
Several years ago, I took some of that old cabling and stripped out the copper wire. I then used that wire as the loop on fishing sinkers. Saved me a good $0.02 - $0.05 per sinker, and I got to go fishing all summer. Life's pretty good sometimes.
Be excellent to each other. And... PARTY ON, DUDES!
This is one of those situations where it's just so *easy* to not take responsibility. I think the final solution in the article is best -- require a fairly large deposit when people move in, on top of requiring them to pay to install and remove the cable they use. If they don't remove it for whatever reason, you just take it out of their deposit.
This is the most logical way to handle the problem, but it puts the business using this method at a disadvantage becuase they are possibly requiring higher deposits than competitors.
dmiessler.com -- grep understanding knowledge
I can't RTFM so I will just say that if you look at some of the mess that companies actually leave such as old cat5 cables 1/2 hanging out the walls as well as some of the under floor.
I did work at a DC once where to lay in new cable under the floor you had to physically have someone to push other cables aside so you could get another cable in. There was meant to be 3 ft of room between the tiles and the concrete floor. IT was all full of cables.
They had a lot of downtime as each time your moved one cable it ended becoming disconnected from the switch or the machine. Soon went bust
Rus
Cheap UK and US VPS
Removing cable can be a little tricky (you don't really want to put new strain on the production cables), but it is generally recyclable which can pay for the operation. However, if you start removing things, you had better make sure that the cables are tagged.
See my journal, I write things there
I don't know if I really believe this article all that much. A couple years back, at the place I work (*cough* will be unemployed from after Wednesday), they upgraded the network to CAT-6 and three times the ports. That meant they had to rewire the entire front office cubefarm, which is two stores with a 6" subfloor each, and wiring columns running between stories.
When all those cables converge on a wiring closet, they start to get bundled up pretty high. There's almost no room to run additional cables, plus it would be a huge unsightly mess. We hired an outside contractor to do the job, so they did professional work and disposed of the old wiring. They almost had to...with a 6" subfloor, you either pull cables through with the old wiring, or rip up every single carpet square and floor tile. I can't imagine this situation being much different for other companies.
...
It surprises me that landlords over there do not take the same view, though it is possible that there is some liability question under US law of which I am unaware.
We are not without our cabling problems here though, my first job was at a major university, in a 1930s building. The original rubber insulated telephone cables were disused but still in place, and they had coagulated into a malevolent black mass in the risers and cable ducts. I am told they have now been removed, I pity the poor people who had to do it, they must have had to cut them out with an angle grinder.
Oxford Dictionaries Online
I know that here in Massachusetts the state laws require contractors to remove unused cable from plenums, raised floors, etc. when doing any renovation that involves those spaces. As was explained to me by one contractor the primary reason is the toxic gasses that can be released by PVC & other plastic coatings when they catch fire. Apparently contractors can be fined if they don't remove unused cables. This actually caused a problem at one place where I worked - we had 3/4 of a floor in a renovated office and the other 1/4 was vacant. When that space was leased out it was rebuilt and one day in the middle of the construction all our network connections on the walls between our space and this other space suddenly stopped working. The contractors incorrectly assumed that these were old cables so they ripped them out. Needless to say they ended up paying to have new cables run, but that took a couple days...
In montreal, we have quite a few buildings where several companies are installed, and when it comes to cabling, you just can not install anything yourself. You rent the space, you rent the lines.
You need a new drop ? No problem, a contractor is on site to install them, label them, keep track of them.
It can lead to some pretty conflicts, but overall, when you get used to the fact that your responsability ends at the wall jack, it's a pretty good way to relieve us IT guys from one of the most boring area of the job.
Marriage is considered capital punishment for the theft of a goat in some third world countries...
..leave a building with unused cables and the street pirates will get it, don't worry.
There is an old hotel where the elevator motors on the roof have had all the copper stripped off and there are holes in the walls where people have torn wiring out.
People have also stolen manhole covers here to sell for scrap, so I guess anything is fair game.
A. Limitation of Knowledge. The guys who do a lot of the wiring work don't know what the cables do -- believe it or not. My two most experienced, and best, pullers couldn't tell you what ethernet was if their life depended on it. Heck, I had one guy who didn't know what T568b was, but could punch down Cat5 to a T568b block in five seconds flat. All they knew was what they were told to install.
In the past I had specifically had discussions with them about pulling cables out. Unless they are explicitly directed by the landlord of the building (who knows even LESS than they do) they will not, and probably should not, touch cables that are pre-existing. This is due to fear of not knowing what they could be doing, and worse, what they are, or aren't, doing.
B. Cross-office runs. In one of my buildings, for example, each floor was an average of 12,500 feet. The average office was 800 sq. ft. Most floors had upwards of 10-12 offices on them. In order to get riser pulls (cabling run in the central, vertical risers of the building) to office drops (termination points for those cables), these typically ran over the other offices. It was typical for the first office, closest to the riser) to have anywhere from 20-40 cables running through their plenum cores that had nothing to do with that office.
Imagine you come in Monday morning, after a neighbor moved in that weekend, to find all your cabling (data, phone, cable TV, leased lines) had be removed by the overly eager data people.
C. Simple CBA. The bottomline for any real estate firm is, well, the bottomline. The risk of fire due to overly full cabling space is fairly minimal compared to the risk of losing money and facing lawsuits -- or worse, losing tenants.
The cost of pulling existing cabling plus the risk of damaging infrastructure minus the value of open space is just not in the favor of making the change. It's really that simple.
When all is said and done, with my engineering cap on, I'd like to see thorough documentation on cables and better diagrams of floors showing what cable goes where -- and it's really not that hard. But try telling a rushing tenant that they have to wait two weeks while your engineering team documents cables, yeah right.
Also, with my engineering cap on, I'd make one suggestion for anyone moving into a new office. If you are going to pull out the old cables, and it is in roughly strong strength, use it to snake your new cables! That's what we often did. There are a few snares with this trick to watch out for, but if you have good pullers they'll know what to do -- if you give them the green light.
"Ain't I a stinka..." - Bugs
Which is why building codes require special jacketed cables for use un plenum spaces (ie: plenum rated). If you install non-rated cables in the plenum space you are breaking the law, and could be liable to future tenants for remove of the non-complying cabling. Yes, that fact is usually ignored since nobody pulls a building permit when retrofitting low-voltage cabling and therfor there's no inspector to make sure it is done correctly (or, at least, to code).
As a structural engineer, I deal with folks every day who do things "wrong" but they've never had a building fall down. I call it Luck, as defined by the myriad little things which don't have any reproducable/quantifiable strucutral value which - in the real world - tend to help out a bit (friction, drywall screws, adhesive on gun-nails, etc.). Combine that with safety factors approaching 3 and the rarity for a building to see a code-required load (usu. less than 2% chance per year) and builders and owners get away with a lot of $#!+.
The fact is that the actual danger is fairly low, but when it's your family member that get's turned into medium steak - crispy on the outside with a warm red center - suddenly the $50,000 to remove the cabling seems like a small price to pay (and would have been a small price compared to the settlement or jury award).
Well, I didn't mean for this to sound so gloom-and-doom. Remember that crispy human with gypsum and ash crust requires multiple failures - bad/blocked exits, non- or sub-functioning alarm and fire supression, ignition source, flammables. Keep your buildings well maintained and you can handle a bit of non-compliance.
Is it just my observation, or are there way too many stupid people in the world?
We actually had a flag day, a few years ago, when a load of new comm. gear came in. The comm. guys spent days pulling up several layers of old cable 'cos they needed the space for the new. It made working under the floor much nicer. Now if we could get the power guys to stop laying 100kg of copper on top of our phone and data cables.... (Yeah, a structured wiring plan would help.)
:-|
And whenever I retire a cable, or find that some less industrious person has abandoned one, I pull it up *now* before it becomes part of a mat that's too much to deal with. It's a great way to be productive late on Friday afternoon when you don't want to touch production software just before the weekend. But then, I actually fasten the holddown screws on connector shells, too, so I'm obviously a fringe nutcase.
If that's what you meant by "inflammable," sorry. The word is "nonflammable."
When I said "inflammable," I meant "inflammable," not "nonflammable." I'm so sorry that you are dead wrong on that one.
According to the article, not some fire code, the cables can be toxic under fire. I was hazarding a guess that what the author wanted to say was that the cable was inflammable, but I might be wrong. The author should have explained what s/he meant by that. If the old cables are a fire hazard now, weren't they a fire hazard when first installed? How does the fact that they are old cables make them more dangerous? What is the problem now and what were the regulational loopholes that created the current state?
Sure they can take the patch panels, but cutting the cables is rediculous. They can disconnect the telco connectors from the punch blocks and take their equipment (thus leaving the cabling intact).
This cutting of cable sounds more like unscrupulous contractors at work.
Money saved and resources usage reduced. The Planet will thank you
Beware of those who profit off the docile and persecute the unbelievers.
IMH(Cowardly)O, the root of the problem is our distinctly American habit of ignoring any financial problem that falls after the coming quarter. Why remove the old tenant's cables when the whole shoddily-built office strip will be torn down or completely remodeled within ten years anyway?
I'm reminded of Steve Martin attempting to impress the English woman in "L.A. Story": "Some of these buildings are over *twenty* years old!"
I think (firefighting and telecom) (training and experience) trump one misinformed article. The insulation on plenum cable does not "burn" in an "inflammable" sense, but id does smolder. (Meaning that it still combusts, but it's much too slow to provide visible flame.)
Unfortunately, the cumbustion does produce toxic smoke, but that's true of nearly all general cumbustion. We don't completely understand pyrolisis in the "real world" yet, so producing a product whose smoke is non-toxic is an empiracle persuit, at best.
There are important points in the article, though. The one that strikes me first is airflow blockage. In fires, there are times when you don't want to ventilate an area, and times when you do. Airflow blockage prevents gases from reaching some places. While this is bad if you need oxygen (for a human), it could be good in the sense that the hot gasses from the fire may not penetrate the building as quickly. (HVAC systems are notorious for that.)
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According to the NEC 2002 ed, section 800.53(A) states that, "Abandoned cables shall not be permitted to remain." Section 800.53(B)(1) states the same thing. So, abandoned cables in plenum & riser spaces MUST be removed according to the NEC. Your local jurisdiction might have something different to say, but that's what's written in the NEC.
Since that's cleared up now, I can move on to your question, "...what about when you have to do both."
Section 800.53(G) & Table 800.53 state that you can substitue cable type CMP (communications plenum) for type CMR (communications riser). You CANNOT substitute CMR for CMP though.
So, the layman's answer to your question is to run type CMP when you have both situations.
Phil
For shipboard installs, The US Navy requires Kevlar jacketed CAT5 vice the more common PVC (PolyvinylCHLORIDE) as PVC releases chlorine gas when burned.
On a side note, when they decomissioned the USS Connstellation (CV-64) a 10'x 10' cable junction between the island and rest of the ship below the flight deck(03 level, i think, i heard this second hand) was completely filled with 40 years worth of all manner of cabling (phones, comms, radar, power) that no more cable could be run through that conduit. My roomate estimated that about 85% of the cable was dead.
Ummm, err, say what, now?
I live in an old house (1840), in the UK, and when we had the floors up we found lead piping for gas lighting, which was the premium source of light before electicity came along.
After admiring the historical quaintess of century and a half old technology, we pulled it up and sold it for enough to cover some of the costs of the woodwork repairs, then laid down CAT5 (attenuation in stone is atrocious, especially for 802.11a, so CAt5 is the backbone).
I hope in another 150 years someone will find the cat5 wiring and find it equally quaint, as they laugh at 100mbit bandwidth and IPv4 net addresses. At least I hope so -as I doubt they will find as much resale value in the wires as we did in the lead pipes.