Route Planning

2 Design Factors –

You can pass a lot of the planning over to B4RN, but the more you know about the way a network ties together, the more likely you will be able to ask the right questions. Some of the planning will be your responsibility. You could pass most aspects of your project over to B4RN, but you can also do the whole thing unaided. No aspect is difficult (apart from getting wayleaves maybe, and B4RN can't help you there). It is quite possible that you have someone among your volunteers who has skills you can use. Use them.

These are the factors which govern the design

• · Every property should be on the map
• · Each property must be connected to a chamber
• · There need to be chambers about every 800 metres to help physically construct the network and to contain spare emergency fibre through the network
• · Chambers should be fairly easy to get to, preferably by vehicle.
• · Each chamber has to link back to the cabinet, usually via a string of other chambers
• · The total distance of digging needs to be as short as possible
• · The Core route (the connection lines between the chambers) especially needs to be as short as possible.
• · The route lines should follow easy routes for digging
• · Each branch that emanates from the cabinet has a maximum number it can connect of 144 properties. (Some spare capacity is needed, so the practical maximum is about 120 properties)
• · Core fibre sizes should reduce towards the ends of the network to reduce costs.

This gives a tree diagram with no loops. Core routes connect chambers and spurs radiate from chambers, but often share trenches for part of their route with Core routes to minimise digging. These lines will be generally across fields.

Turning the map into a viable route is up to the volunteers. They must

• · Inspect all the routes to see that they are feasible and that there are no simpler or cheaper variations
• · Get permission from landowners to dig those routes
• · Comply with any landowners who want it to take a particular route across their land
• · Find every property and any possible future connections that might be needed
• · In particular consider alternatives for the expensive bits such as road and river crossings

There may be bits that can be excluded from the detailed planning to start with. For example, the urban bits might involve a lot of people and a lot of complications, and they can be put on hold until later.

There may be whole sections that can be considered pretty much as a separate unit – like a hamlet or valley. That will simplify the overall task, especially if you have a local leader you can pass the work over to.

Some sections of the map will be easy to consider in isolation. Often routes follow the same general lines as the roads do, because that’s where houses tend to be. The duct line will often be roughly parallel to the road, but in the fields, and enter the houses from the back. This usually means that there are road crossings in the plan, to reach houses on the other side of the road. This will be something the volunteer will be assessing – trying to find good places to cross the road (farmers sometimes have their own routes under roads) and to determine which side of the road is best for the main line of chambers.

6 Tinkering with the design

To change the routing a lot you need to understand the constraints of the fibre network. Or at least be aware of what changes make no difference - like the specific route across a field or moving a chamber 20 metres does not matter.

Deciding to connect a house from a different chamber can sometimes make significant changes to the network and sometimes make no difference whatsoever. You can change the route to a single spur pretty much how you like, it doesn't affect much.

Within a Sector, you can change quite a lot of things

This is a real example – it is the Blue area in the previous map, it has 7 Sectors

Inside the first Sector (Cabinet to 703)

you can make any of the following changes -

• change the line of the Spur routes
• change the line of the Core route

these changes may affect the chamber or bullet size -

• supply any of those 22 houses from a different chamber within the Sector (701, 702, or 703) or indeed direct from the Cabinet
• supply any of the houses beyond 703, from 703

these changes can affect fibre counts, chamber sizes and bullet sizes

• supplying any of those 22 houses from a chamber beyond 703
• Identifying more connections needed in the sector up to 703
• Identifying more connections in the rest of that network
• Not being able to connect the chambers in that pattern, say 703a has to come from 704 rather than 703

Notes

• · If say a house was located between 703 and 704 but nearer 704, it might still be worth suppling it from 703 before the fibre count changes
• · Once you have the 192 fibre installed to 703, then you can only supply a maximum of 96 properties in this whole section. There are 77 properties on the map as drawn. If you wished to re-jig an adjacent area and suddenly want to tack another 20 houses on to this area, it is too late.
• · Provision is made for spares spread through the network, so a 192 fibre count will never be planned to supply as many as 96 properties

7 Your Sector build

You want to complete all of the Sector up to 703 at the same time because the fibre should be continuous without a join. If you happened to have another Sector ready before B4RN turn up, then that might well receive its fibre at the same time. So you could decide to go further and get to 703a or 704/5 - those would be your next priority.

Your strategy would be

1. Get 'Cabinet to 703' ready plus spurs to a lot of those houses

2. Tell B4RN you are ready for fibre in that Sector

3. Get some idea of how long it will be before B4RN turn up and try to get one of the next Core Sectors finished. (concentrate on the Core route, it is more difficult to arrange to get the Core fibre installed than Spur fibre)

4. If they haven’t arrived, try to get another adjacent Sector ready.

5. Keep B4RN informed as to newly completed sections.

6. Once B4RN have been and given you some fibre, you can move on to continue your network. The Core route is your priority since it takes a while to be able to arrange to get fibre for it. However, if you have a large number of houses ready to go live then B4RN will have more incentive to come and give you Core fibre.

Your first task in all that is to get the bit up to 703 completed plus some of its spurs. How you tackle it will probably depend on what landowners are involved in that section. As it is the section starting at the Cabinet (which is likely to be in your village centre) you might have a complicated beginning to your route. You will also have to consider the other Sectors that begin at the Cabinet, since you may be sharing trenches with them.

Your first plan might be to get all the bits of one particular landowner’s land finished. You might have access to a plough or a digger or both. You might have some keen volunteers who you would like to get working at walls, streams, whatever. You need to draw a plan, write a list of all the bits in that Sector and whether they need ploughing/digging/manual labour.

You might also be considering trying to recruit volunteers

Soon you will want to get something constructed. You could get odd bits of manual stuff done, you might get hold of someone with a digger to do a small section, but eventually you are going to get to have a proper longer session.

That gets you to Dig Day

Keep it flexible. Adjust for weather. Motivate your volunteers. Good luck.

Route Choice

The Core route is more expensive than the spurs. So the Core route should follow a general direction rather than zigzag between all the houses.

(This also depends a bit on what size fibre it is - laying the biggest fibre is around £6 a metre and the smallest £2.50 a metre - compared with about £2 a metre for laying spurs)