1. Dial Before You Dig (DBYD)
Before starting any project we must call DBYD to ascertain who owns underground infrastructure in the area and roughly where it is. These plans all come in various scales and qualities so they cannot be relied on 100%.
Our civil engineers design the route, taking into account existing conduits and fibers that can be used.
3. Locating assets
Knowing roughly where other assets are from DBYD we use non destructive digging, which involves spraying high pressure water into the ground and sucking up the muddy soil into a truck. This ensures that any existing pipes aren’t damaged, although it is time consuming and labour intensive and the pumping truck is also costly.
4. Directional Drilling
To minimize restoration costs our preferred method is to use a horizontal directional drilling truck as seen in the picture above. This means that footpaths don’t need to be dug up. The process is fascinating to watch as the machine is loaded up with drilling rods that are hollow and spray high pressure water into the soil. Once the machine has drilled one rod into the ground it automatically attaches another rod to the end of the first and continues drilling. The process requires one person to drive the machine and another to locate the drill head and warn the operator when to stop and what direction to take. When other assets are discovered using the locator drilling must stop so that more non destructive digging can take place.
5. Installing conduit
Once the directional drill run is completed the drill rod is attached to a coil of plastic conduit and the rod is pulled back through the newly drilled hole, leaving the conduit in the ground.
6. Installing Pits
A small excavator and shovels are used to dig a hole for the pit. Pits are needed to join conduits together and larger pits are needed to hold the waterproof protective splicing covers that join all the fiber cables together. Pits are often installed in strategic locations to allow for new clients to be added to the network without having to cut existing fiber services.
7. Rod & Roping Conduit
Once the conduit is in and ready the rope (blue and yellow rope that you often see on Telstra trucks) is installed. This is either done using a rod, or when possible a balloon is attached to the end of the rope and blasted through the conduit with high pressure air. This method is very fast and can install rope over several kilometres in a short period of time.
8. Hauling fiber
Once the rope is in, it is attached to the strength member of the fiber cable (as the fiber strands themselves are very fragile) and the fiber cable is hauled back through conduit with coils of spare cable usually left in the pits so that repairs can be made to the network.
9. Splicing & Testing
Having determined which fibers are going to be used for the customer circuit the splicer will join each segment together to form one long continuous fiber. This method is called splicing and is extremely intricate and requires a splicing machine worth approximately $20,000. The splices are reinforced with a small piece of metal housed in heat shrink plastic. This is then sealed up into a splicing tray. When the circuit has been spliced end to end the splicer will use a testing machine to work out how much loss is caused by each of the joins. The better the quality of the joins the less overall loss on the fiber.
When the job is completed all of the footpaths, driveways and topsoil that were disturbed by the works must be replaced as it was prior to commencement. In rare and unlucky circumstances any existing assets that are damaged such as water pipes or sewerage must also be repaired at our expense. Asset holders will also demand compensation if their assets and clients are affected.
11. Updating As builts
After the network has been changed these changes must be reflected on the civil engineering diagrams and submitted to Dial Before You Dig for other people working in the area to become aware of.