Fibre through existing domestic cable duct?

[SteveWest]

@ptrduffy  Thanks. Yes, I bought a reel of thin cord today and I'm going to try pulling it in behind the coax. The difficulty or otherwise of getting the coax out should give me some idea of the practicality of using the duct. For instance, I should get some feel for how tight the corners are!

[Paul608085]

@SteveWest 

Are you by any chance in Milton Keynes, or another town/city that used to have BT Cable TV?

I am in MK, and was hoping to use the tube from the wallbox in the front wall of our house to the lounge TV position when Openreach get around to fibreing our area.

I don't think that you will have to worry about tight corners, coax should not be bent anyway and the cable used in our house has a solid dielectric which makes it stiffer than air-spaced.

[SteveWest]

@Paul608085  Hi Paul. No, not Milton Keynes but yes this area had cable TV put in by BT. The developers put the ducting into the house, probably in co-operation with British Telecom, as it was named then.  So it seems like we're in a similar position. I think my coax has also got a solid dielectric so I'm not terribly worried about the bends in the duct, but I should have a better idea when I pull the cable out later today--unless it pours with rain. The external wall box has to be opened with a square key and is a bit awkward to get open, especially as previous people seem to have opened it by wedging a flat headed screwdriver into the square hole--at least, that's what it looks like.

[Paul608085]

@SteveWest 

Why not leave the coax in place for now, the Openreach installer may want to use it to pull the fibre or tube through?

"The external wall box has to be opened with a square key and is a bit awkward to get open, especially as previous people seem to have opened it by wedging a flat headed screwdriver into the square hole--at least, that's what it looks like."

Ours has more of a crescent shaped keyway, which also requires a special key to open it properly. I think that BT also used it on their CCTV cabinets? Few Openreach people seem to have the correct key these days, but luckily I managed to acquire one!

@pippincp 

"Openreach cannot use another providers duct even if it is no longer in use."

"If the duct was supplied by the builders of the house then it isn't another provider as in Communication company."

But if the duct originally contained a cable, (in this case the coax), fitted by BT/Openreach, then how would they justify not reusing it for another of their cables?

[SteveWest]

@Paul608085 Too late! I didn't read your message until after the cable was out. The coax--which must be getting on for 50 years old--pulled out very easily so there can't be any sharp corners in the duct. I pulled in a length of cord behind it so the OpenReach engineer has got something in there for pulling in another cable. In fact I pulled in a pair of cords because I've also got a cunning plan that I might be able to use the duct as part of a convoluted route to get a Cat6 cable to one of the upstairs rooms.

[Paul608085]

@SteveWest 

"I might be able to use the duct as part of a convoluted route to get a Cat6 cable to one of the upstairs rooms"

Is your house similar to mine then, with another duct from the front wallbox carrying a second coax to a TV socket in the master bedroom?

[SteveWest]

@Paul608085  No, unfortunately not. The house was built in the 70s when the concept of master bedrooms had not really caught on, and the idea that someone might want a TV in the bedroom was probably considered totally decadent. But I might be able to get from the BT box via the wall cavity to a void which would take my ethernet cable upstairs and then to the spare bedroom which needs the wired ethernet.

[pippincp]

"But if the duct originally contained a cable, (in this case the coax), fitted by BT/Openreach"

You really want me to answer that dumb question?

What if the duct originally contained a coax from YM/O2, Cable & Wireless or NTL or TeleWest or even Granada or Redifusion.

I don't recall Openreach ever supplying a coax cable for any service but am willing to be shown wrong.

What if a cable company supplied the builder with the duct and they'd agreed on exclusive supply for a year or more?

The OP will find out if the duct can be used when the install engineer attends. No ifs, buts or maybe's if the engineer says no then that's it. If he says yes, then happy days!

[SteveWest]

@pippincp The original local cable TV system was definitely installed by BT (or, rather, its predecessors) in the 1970s. There are still a few of the old green street pillars around with GPO embossed on them, which were part of the cable TV distribution network. The coaxial cable to my house comes from a nearby BT footway box, through a duct that also contains the phone cable. Both arrive in a box on the outside wall of the house. The duct inside the house could only have been installed by the builder and it leads from that wall box to the place where they thought the TV ought to be.

As you say it all depends on the engineer who turns up on the day. He may take the view that the duct is of unknown provenance and therefore not to be touched, or (again as you say) May go for the “happy days” option.

Thanks all for the advice and interest in my problems. I’ll let you know what happens.

[SteveWest]

I thought I'd just report on the final outcome.

The engineer came today and was a bit reluctant to use the internal duct--because we really don't know much about the state of it or the sharpness of the bends. However, the nearest footway box with fibre access turned out to be at the end of the road and, by the time he had brought a fibre to the house, there was only a very small length left for the splice. So at that point he changed his mind and decided to try the duct. The final result is that the external fibre comes to the house entirely through the old PSTN/TV ducting; the splice is in the wall box on the front of the house; and the internal fibre goes through the internal ducting. So there is nothing visible externally and a few centimetres of fibre internally.

My main motivation for getting full fibre was that fibre-to-the-cabinet was only giving an upload speed of about 2.5Mbit/s. The upload speed as of this afternoon is about 28Mbit/s (download 148Mbit/s).

The installation engineer was very helpful and left everything very tidy. A great result