By Carmen FerriPublished on
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APC’s local access and community networks team hosted a webinar called “We ♥ Bamboo: How to grow and construct your own bamboo masts for extending rural connectivity – sharing experiences”. The aim of the webinar was to offer guidance to those who would like to build bamboo community network towers or further develop their work in this area. The organisers invited practitioners from India, Indonesia and Mexico with field experience in using bamboo for construction to share their knowledge and explore opportunities to use bamboo towers for extending rural internet connectivity and connecting the unconnected.
The webinar also covered the broader role of bamboo in addressing community needs for local construction materials, along with the spin-off benefits and income generation for the community that can be acquired by the usage of bamboo. The topics covered included the planting and treatment of bamboo, the many different ways to use bamboo to support local communities, important design parameters for durable structures, and construction and maintenance.
Using bamboo to support local communities
Bamboo can be used to build community network towers that are extremely important for expanding connectivity, especially in remote and rural areas. Bamboo significantly reduces the costs of building the towers: because it is a local resource, it can be harvested and then used to build the towers by community members themselves.
Bamboo presents an important opportunity as it is strong, fast-growing and a prominent feature of the rural landscape in large parts of the world. The benefits of bamboo are that it is a renewable and versatile resource that is characterised by high strength and low weight. It is the world's fast growing woody plant, usually growing 7.5 to 10 centimetres in a day, and has historically been used as a low-cost building material.
A bamboo tower costs approximately USD 320, as compared to the USD 1,380 cost of a galvanised iron tower. In terms of an overall life-cycle cost comparison, a bamboo tower ends up being 18% less expensive than a galvanised pipe tower of equal height. Bamboo is also an extremely durable material which is earthquake resistant, and has a better ecological footprint as compared to galvanised iron, steel and other materials commonly used for community network towers.
Construction with bamboo can easily be adapted to various types of bamboo found in different regions, and because it is a local resource, it enables community ownership of connectivity, which also enables community participation. This takes on particular importance given the fact that the high cost of network infrastructure is one of the primary causes for low penetration of connectivity in remote rural areas. Towers for signal relay, and often for picking up a connection at the local premises, are a key part of the infrastructure required to provide rural connectivity and are perhaps one of the most expensive elements of infrastructure in any rural network deployment. To enable connectivity to unconnected areas, cost-effective solutions are needed that can minimise the cost of towers and rely as much as possible on local resources. This ultimately results in more community-based ownership and responsibility for the maintenance, upkeep, costs and service.
Planting and treatment of bamboo
There are more than 70 genera of bamboo divided into about 10,000 species, which are found in diverse climates, from cold mountains to hot tropical regions. The physical and environmental properties of bamboo make it an attractive material to meet a wide range of purposes. This was explained by Klaias Andhale from India, who offered a presentation on bamboo nursery techniques and cultivation among tribal communities in Maharashtra state. Andhale shared the experience of his programme, which effectively established bamboo nurseries with the purpose of both vegatative propagation and seed propagation. Andhal’s primary focus in growing bamboo is to promote crop diversification. “Crop diversification through bamboo plantation yields excellent returns,” he noted, adding, “It not only enriches the environment but also generates employment opportunities and supports the local economy.”
For his part, Pon Purajatnika spoke about the multiple treatment processes of bamboo used in his work in Indonesia, such as soaking bamboo in rivers, ponds or rice fields, immersion in organic water, boiling with an organic preservative mixed with water, and fumigation systems. The best growing and treatment techniques differ in accordance with the type of bamboo, regional climate and available resources, he explained.
Design parameters for durable structures and construction and maintenance
Professor Siddhartha Ghosh from the Indian Institute of Technology-Bombay spoke on the structural engineering of bamboo community network towers. Ghosh highlighted that when building a network tower, the most important things to keep in mind are wind loading, material property, uncertainty, geometry and load paths, and constructability and connections. He based the building of bamboo towers on the specialised design structures that are normally used when building a steel tower – these standards can differ between countries. The structural design of the bamboo tower is important, as it will determine if the tower is safe.
There are multiple countries with specific standards for building with bamboo, he noted, and although these standards differ, very few look into the importance of structural design when building network towers with bamboo, as it is a material that has only recently started to be used for structural design on a large scale. When building network towers, wind loading tends to be the most important issue with structural design. While bamboo is durable, tall and flexible, bamboo structures are sensitive to wind loading.
Design structures are still being developed, and it remains a challenge to build bamboo towers to be safe, and therefore it is important to keep in mind the material strength of each piece of bamboo, Ghosh stressed. While offering an overview of best practices to date, he highlighted that there are still many areas that need to be examined to ensure safe and durable structures , and emphasised the need to develop a manual for grading, testing, design and creation of design drawings that can be applied across different countries.
Watch the full webinar here: