The Fibre Stage

The Core Fibre Stage explained in detail here. The House Fibre Stage explained in detail here.

The join in the chamber is a Bullet That big tin box is the Cabinet

Finally you reach a stage where a whole sector of Core and a set of houses are ready. Walk the whole route. You will find one or two places where it needs a bit more infill, you will find some discarded bits of duct, you will check that all walls and fences have a marker. The marker can be very obvious but temporary, to be replaced with a subtle marker after fibre has arrived. You may find a couple of places where the duct can be seen that need to be sorted, if this has to be done later, then fibre can still be blown. If you have a point with lots of joins, where you suspect a problem, then the hole could be left open until after fibre.

Here, someone did not walk the route and notice a join hadn't been done at all. When they came to blow fibre, after a bit of head-scratching as to why the air test wasn't working, a loud hissing was found in the adjacent field.

There will come a day when you are ‘ready for fibre’, you may have done all the work yourselves up to now, but now you need B4RN.

“Ready for fibre” means you have a sector of your area ready with all the ducting, chambers and your cabinet prepared such that if you had fibre in your ducts, some joints at chambers and a bit of magic at the cabinet then some houses could go ‘live’.

You can see there are several jobs for B4RN there. When you are ready for your very first sector to go live, B4RN will probably turn up in force and flurry around doing all the work and you will have houses live within a week of them arriving.

Later, when you get other sectors “ready”, B4RN may not work this way and some jobs will get done at different times. This is partly due to the fact that the B4RN personnel tend to specialise. Several of the staff can do all the sub-tasks but tend not to.

What are the tasks?

Core Fibre – that’s the black bundle of fibres that goes down your 16mm ducts. This job needs a team of 3 to 6 people and may involve digging for faults, it needs the trailer and an expensive drum of fibre.

House Fibre – that’s the thin white stuff that goes from the chamber to every house. This is a simpler job with smaller kit, but it needs a compressor. It can involve digging but not so often. That needs 2 people, but 1 B4RN person and a volunteer should be able to cope.

Splicing Bullets – the joints at chambers is the most specialist. Joining up to 300 fibres in a day takes a special person. They work in teams of 2 and usually just get on with the job, maybe not even informing you that they are in town.

House Splicing – finishing off the router backplate and adding a router also involves people who tend to specialise. They work as individuals but need volunteers to arrange access to houses. This is the only part of the operation where you need to enter the house.

Inside the Cabinet – there are two different jobs here. One is a splicing job to prepare the ‘trays’. A tray is where the individual fibre to your house ends in a socket - if you shone light down this socket it would reach your house. So each house has its own unique socket in the cabinet

If your socket is already prepared in the cabinet then the 2^nd job is very simple – to link that socket with a short cable to an Optic. The Optic is a socket on a different sort of cabinet unit called a Switch.

As you gradually add live houses in your village, then occasionally a new tray will be needed when you have run out of sockets, or a new switch when you run out of optics The ‘trays’ job is done by the same people that do bullets, but if there are sockets available then ‘patching’ is very simple and any B4RN person can do that.

(The cabinet is has other parts as well)

So you may be involved with 4 sets of people as there are 4 jobs.

Core Fibre House Fibre Bullet/Cabinet Splicing House connection

They do not have to be done in sequence. It will often be better not to.

Some jobs are sometimes convenient to lump together.

Core fibre is a big job and takes more organisation, and occasionally there may be a delay in supplies being available of the size your section needs. You may be waiting for core.

In the meantime you can have readied a lot of houses with house fibre, and routers even.

Then when the core arrives you will be waiting for bullet splicers.

So you need a manager volunteer – someone who knows what stage your sectors are at and knows what team to try and call in from B4RN. You will know some of the B4RN people already – they all can advise. Remember that you are competing with other villages for your work to get done.

Be a competitor.

Core Fibre

Fibre can only be blown a certain distance before the mechanical effort of pushing it is too great. This depends on the particular size fibre bundle, how hilly the route is, how many tiny dents you have put in the duct. So in order to gain access to the duct, chambers are put in on the longer runs every so often, even when there are no house spurs at that point. These are called blowing chambers. They will contain about 20 metres of spare fibre but do not usually contain a bullet. They are spaced at no more than 1000 metres, which is a full drum of 16mm.

In a long run of a few kilometres between villages with no houses, there might be several blowing chambers. The fibre passes through the chamber without a join, and the spare 20m is coiled inside.

To explain simply. You have two villages about 3km apart with 2 intermediate chambers at the 1km and 2 km marks. You start at one village with 3km or so of fibre, you blow it all through to the first intermediate chamber, where you coil 2 km of fibre neatly onto the grass (fleeting). You start again blowing all that fibre from that chamber to the next chamber, and blow the remaining 1km of fibre out onto the grass. Then you blow this towards village 2 and it just reaches. You then have a few adjustments to make to leave about 20 metres in each blowing chamber. Once the intermediate chambers are sealed, they are unlikely to ever need visiting again.

If there are a couple of houses along the way, then there will have to be a bullet. (And you might consider having a chamber close to the houses as it minimises the spur length) At this bullet, only a few of the fibres in the fibre bundle are actually cut, in order to join them to the house fibre which will be in the spur ducts - most of the fibres in the bundle will continue uncut. This makes it a fairly simple job to put the bullet in.

You could join the whole bundle at a chamber if you had to (if for example it would be a long time before the duct could be completed beyond a particular chamber), but you obviously prefer not to.

This becomes even more true for the largest size bundle which is a 288f, nobody wants to join a 288. However, being the largest size it is the most likely to get stuck and it will not be an easy job getting a 288 through a section of several chambers without a join somewhere. Joining a 288 will take 2 people a day, and a not very exciting day.

This is the machine that shoves the fibre down the 16mm orange tubes that you've just laid.

It holds the orange duct tightly and grips the black fibre bundle between two chain belts. The belts rotate to push the fibre into the duct. This is driven by a compressor.

Another compressor is pumping air into the duct at the same time. This acts as a secondary drive force, fluttering the duct along rather than pushing it.

The machine also adds a little oil to the proceedings at the same time.

(In fact, you can manage with a single compressor doing the blowing and the pushing)

The fibre blowing operation isn't really about the mechanics of getting the fibre in, it's about the logistics of working along a section of several chambers and solving the problems you come across.

When a complete section of core route is continuous from the starting chamber to the next chamber where the fibre count changes then you are ready to get fibre blown into it. Where this section starts, and finishes is ascertained from the spreadsheet.

All we do is to e-mail B4RN to tell them that section is ready. It gets a quicker response if a lot of houses are ready to have their fibre blown at the same time, or if that has already been done then this will increase B4RN's enthusiasm.

Blowing in fibre is a job where B4RN do all the work and they can do this without any volunteer assistance (in some cases they prefer it that way). A volunteer can help the process along however, and we always insist we are there. Someone should really be there because someone needs to liaise with the landowners. Even if you are just going to leave B4RN to it, it is useful to understand the whole procedure so that when you do your own planning and get digging organised you can make their job easier and eliminate some likely problems.

And you need a volunteer around that knows that section and can help locate the line of the duct and where the joins are in case a fault has to be located.

What can go wrong

We have had about 10 visits from B4RN to do sections of Core Routes, ranging from half a day to 2 weeks. We have over 30km of Core Route now with fibre.

Faults – 12 in Total

9 occasions where the duct was crushed by rocks and the core fibre couldn’t get through. three of these were on the Supply Route between us and Barbon where there was 6km of rough rocky verge. Of the other 9, two were in a section that should really have been put in outer ducting, but no volunteers were there at the time to supervise (which rarely occurs).

2 faults at the same location where joints had been put in the middle of a tight bend.

1 where someone had forgot to finish off a joint. (Two 16mm duct ends sticking out the ground, one of them hissing away with the compressed air)

So, to sum up – there were 3 in the verge where it was really tough going, 3 that we learnt from and 6 that occurred because it’s quite rocky here.

We do not go out of our way to avoid joins, we do not de-burr them and they do not appear to cause problems so long as they are not on bends. That is our experience.

There have been 4 or more occasions when the duct had to be cut into to do a fleet at a point between chambers.

And 2 occasions when the core fibre has been damaged in the blowing process. 1 survived with a little bit of taping. 1 needed a long new chunk of core fibre.

House fibre installation

Blowing the fibre into the 7mm ducts from the chamber to the house is a different operation from Core fibre blowing - okay, you have a machine pushing and blowing fibre down a tube, but the scale is much smaller and you may need to start to involve the householder.

It doesn’t require the use of a trailer, but if there are quite a few house connections to do and especially if there is other work to do on bullets or at the cabinet then B4RN might work from their horsebox trailer. Otherwise the equipment would fit in the boot of a car. A compressor, a blowing machine and a drum of duct.

It is simple enough that given an hour or two's training and the gear, you could do the operation yourself. It is certainly a job where you can do the house end of what is really a 2 person job. (That means you only need to get hold of 1 B4RN person)

The house fibre can be blown from the house end to the chamber, which can be a good idea if the chamber is a long way down a hill from the house.

**It can also be blown from house to adjacent house - all you need to do is connect the right two ducts across at the chamber. I did that one with Paul once - I think we must have been without radios or something - I shouted over the wall to Paul when the fibre got to the next-door property I was at. Return to chamber. Cut. Two houses fibred. Job done.

The procedure in its simplest form is;

Person A sets up a blower unit (driven by a compressor) at the chamber. This will push 2-core fibre down a particular 7 mm spur. The fibre will self-feed from a medium-sized drum.
Person B is waiting at the other end at the house and radios back to the chamber when the fibre gets there.
Job pretty much done. Person B moves on to next house. Repeat.

If the house owner is in, then the fibre can be blown right through in to the house to the router backing plate and a metre or so spare duct is wrapped into the plate. If the owner is out, then a longer length of fibre is left outside the house. In this case someone needs to know the distance to the router inside the house, so that enough fibre can be left. (This spare fibre is the bit they use if they have to make a join in your garden because you have gone through it with the garden fork)

A volunteer is almost essential for this part to talk to the house owners and to locate the house in the first place. Given a radio they can at least say when the fibre has reached the house, and, given about two minutes extra training they can complete the house side of things.

Also, in cases where the fibre couldn’t be threaded through the wall because the owner was out, this slightly skilled volunteer can feed through and finish off some days later when the owner is about, without having to call B4RN back in.

This simplifies all the fuss about householders having to be in when B4RN come and leaving keys with people, etc. You can do it that way of course, but you don’t have to. You just turn up and blow as many as you can, all the way into houses if there is someone at home, and all the others where people are out you blow to the wall outside.

· The volunteer is also useful for being able to locate or borrow a ladder for example.
· There will also be questions from the owners or information that needs to be acted on.
· There will be people to try and locate.
· and the unexpected.....

Faults during our house fibre blowing:

5 faults total in well over 150 house blowings.

3 were joints on bends early in our career.

1 case where the mole plough had somehow mangled the duct but not quite breaking it when it was installed.

1 duct had a lot of water at a low point and had to be cut and bled out. Since you are leaving one end of the duct in the care of the householder, there should be more problems than there are.

We also had one case where a volunteer pulled too much fibre through into the house and was pulling it all the way from the chamber. So, it had to be re-blown. (It was funny though)

Again no problems with joins as long as they are not on bends.

From what I have heard them say, water in the duct is apparently one of the biggest problems. We have had one spur with that problem and that is it. There again we do not often use end caps, we prefer taping.

Every picture tells a story

There's a nice game you can play eventually. A nice complicated picture of a chamber being worked on. What's going on here?

Core fibre, one of the smallest sizes 24 ?, has just been successfully fed though to the next chamber. There are 7 spurs, 4 of which have already got their house fibre. Someone's probably going to finish off the bullet here today, it'll only be a small one Those 4 houses might go live by the evening.

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