Hello, everyone!
Today, I want to continue to explain a new topic – ODN engineering and maintenance. Now, I will start to explain ODN engineering. Today, the topic is the civil work of ducts. Let’s get started.
The trench has 5 levels: bedding, padding and three layers of backfills. After the first layer, PVC pipes are laid, then the second layer goes over them. These first two layers are sand, both 150 mm deep. After that, the third layer at a depth of 300 mm is the backfill. Then comes the marker tape and two more layers of 300 mm and 200 mm. This is for a classic trench, for a micro trench everything is much smaller. But that is the subject of a special article.
Pipes that are installed for optical cables are PVC or HDPE pipes. The pipes are usually coiled, and it is about 500 m. If a longer length is required, the pipes can be continued with special elements. Also, if the pipes are not used, they should be closed and thus prevent the penetration of water and moisture. The inside of the pipe should have grooves so that air can flow. The pipes must withstand a certain pressure. Fiber optic cables can be installed by manual retraction in a tube or by a blowing machine.
Manholes and handholes are places to store optical cable reserves, optical closures, etc. They should enable the safe and uninterrupted work of technicians. Prior to the works, provide the construction site with traffic signs and barricades. Manholes should allow technicians to enter. Before entering, the presence of hazardous and/or flammable gases is checked with a special instrument. The tool is not thrown but carefully lowered. Splicing into manholes is prohibited due to the danger of ignition and explosion. Prefabricated concrete elements are used for realization. Manholes and handholes have multiple entrances and exits, those that are not used should be closed. And to prevent water penetration.
This is the end of this article. I will continue to explain this topic in the next article >> ODN Engineering and Maintenance (12).
Thank you!
